DAIKIN D-EOMHP01301-20 Air Cooled Chiller/Heat Pump User Manual

June 6, 2024
Daikin

D-EOMHP01301-20 Air Cooled Chiller/Heat Pump

REV

02

Date

April 2021

Supersedes D-EOMHP01301-20_01EN

Operating Manual D-EOMHP01301-20_02EN
Air Cooled chiller/heat pump with scroll compressors
EWYT_B EWAT_B

TABLE OF CONTENTS

1 SAFETY CONSIDERATIONS ……………………………………………………………………………………………………………………….. 4 1.1 General……………………………………………………………………………………………………………………………………………….. 4 1.2 Before switching the unit ……………………………………………………………………………………………………………………….. 4 1.3 Avoid electrocution……………………………………………………………………………………………………………………………….. 4

2 GENERAL DESCRIPTION …………………………………………………………………………………………………………………………… 5 2.1 Basic Information …………………………………………………………………………………………………………………………………. 5 2.2 Abbreviations used……………………………………………………………………………………………………………………………….. 5 2.3 Controller Operating Limits ……………………………………………………………………………………………………………………. 5 2.4 Controller Architecture ………………………………………………………………………………………………………………………….. 5 2.5 Communication Modules……………………………………………………………………………………………………………………….. 6

3 USING THE CONTROLLER …………………………………………………………………………………………………………………………. 6 3.1 Navigating …………………………………………………………………………………………………………………………………………… 6 3.2 Passwords…………………………………………………………………………………………………………………………………………… 6 3.3 Editing ………………………………………………………………………………………………………………………………………………… 7 3.4 Basic Control System Diagnostic ……………………………………………………………………………………………………………. 7 3.5 Controller maintenance …………………………………………………………………………………………………………………………. 8 3.6 Optional Remote User Interface …………………………………………………………………………………………………………….. 8 3.7 Embedded Web Interface ……………………………………………………………………………………………………………………… 8

4 WORKING WITH THIS UNIT ………………………………………………………………………………………………………………………. 10 4.1 Chiller On/Off …………………………………………………………………………………………………………………………………….. 10

4.1.1 Keypad On/Off ……………………………………………………………………………………………………………………………. 10 4.1.2 Scheduler and Silent mode functionalities ……………………………………………………………………………………… 11 The Fan Silent Mode function can be enabled only for units equipped with VFD fans. ……………………………………… 12 4.1.3 Network On/Off …………………………………………………………………………………………………………………………… 12

4.2 Water Setpoints………………………………………………………………………………………………………………………………….. 12 4.3 Unit Mode ………………………………………………………………………………………………………………………………………….. 13

4.3.1 Heat/Cool Switch (Heat Pump Only) ……………………………………………………………………………………………… 14 4.3.2 Energy Saving mode …………………………………………………………………………………………………………………… 14

4.4 Unit Status…………………………………………………………………………………………………………………………………………. 14 4.5 Network Control …………………………………………………………………………………………………………………………………. 15 4.6 Thermostatic Control …………………………………………………………………………………………………………………………… 16 4.7 Date/Time………………………………………………………………………………………………………………………………………….. 17 4.8 Pumps ………………………………………………………………………………………………………………………………………………. 17 4.9 External Alarm……………………………………………………………………………………………………………………………………. 18 4.10 Power Conservation……………………………………………………………………………………………………………………………. 18

4.10.1 Demand Limit …………………………………………………………………………………………………………………………….. 19 4.10.2 Setpoint Reset ……………………………………………………………………………………………………………………………. 19

4.10.2.1 Setpoint Reset by OAT (A/C units only) …………………………………………………………………………………. 20 4.10.2.2 Setpoint Reset by External 4-20Ma signal………………………………………………………………………………. 21 4.10.2.3 Setpoint Reset by DT …………………………………………………………………………………………………………… 22 4.11 Electrical Data ……………………………………………………………………………………………………………………………………. 22 4.12 Controller IP Setup ……………………………………………………………………………………………………………………………… 23 4.13 Daikin On Site ……………………………………………………………………………………………………………………………………. 24 4.14 Heat Recovery …………………………………………………………………………………………………………………………………… 25 4.15 Rapid Restart …………………………………………………………………………………………………………………………………….. 25 4.16 FreeCooling (Cooling Only) …………………………………………………………………………………………………………………. 27

4.16.1 FreeCooling Switch …………………………………………………………………………………………………………………….. 29 4.16.2 Network On/Off …………………………………………………………………………………………………………………………… 29

4.17 Collective Housing (Changeover Function, Heat Pump only) …………………………………………………………………… 29 4.18 Software Options………………………………………………………………………………………………………………………………… 31

4.18.1 4.18.2 4.18.3 4.18.4 4.18.5

Changing the Password for buying new Software Options ……………………………………………………………….. 31 Inserting the Password in a Spare Controller ………………………………………………………………………………….. 31 Modbus MSTP Software Option ……………………………………………………………………………………………………. 32 BACNET MSTP ………………………………………………………………………………………………………………………….. 33 BACNET IP ………………………………………………………………………………………………………………………………… 34

5 ALARMS AND TROUBLESHOOTING…………………………………………………………………………………………………………. 36 5.1 Unit Alerts………………………………………………………………………………………………………………………………………….. 36

5.1.1 5.1.2 5.1.3 5.1.4 5.1.5 5.1.6

BadLWTReset – Bad Leaving Water Temperature Reset Input …………………………………………………………. 36 EnergyMeterComm – Energy Meter Communication Fail …………………………………………………………………. 36 EvapPump1Fault – Evaporator Pump #1 Failure …………………………………………………………………………….. 36 BadDemandLimit – Bad Demand Limit Input …………………………………………………………………………………… 37 EvapPump2Fault – Evaporator Pump #2 Failure …………………………………………………………………………….. 37 Switch Box Temperature sensor fault ……………………………………………………………………………………………. 37

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5.1.7 5.1.8 5.1.9 5.1.10 5.1.11 5.1.12 5.1.13 5.1.14
5.1.15

ExternalEvent – External Event …………………………………………………………………………………………………….. 38
HeatRec EntWTempSen – Heat Recovery Entering Water Temperature sensor fault ………………………….. 38
HeatRec LvgWTempSen – Heat Recovery Leaving Water Temperature sensor fault…………………………… 38
HeatRec FreezeAlm – Heat Recovery Water Freeze Protect alarm …………………………………………………… 38 Option1BoardComm ­ Optional board 1 communication fail …………………………………………………………….. 39 Option2BoardComm ­ Optional board 2 communication fail …………………………………………………………….. 39 Option3BoardComm ­ Optional board 3 communication fail …………………………………………………………….. 39 EvapPDSen ­ Evaporator Pressure Drop sensor fault …………………………………………………………………….. 39 LoadPDSen ­ Load Pressure Drop sensor fault ……………………………………………………………………………… 40

5.2 Unit Pumpdown Alarms……………………………………………………………………………………………………………………….. 40

5.2.1 5.2.2 5.2.3 5.2.4 5.2.5

UnitOff EvpEntWTempSen – Evaporator Entering Water Temperature (EWT) sensor fault…………………… 40 UnitOffLvgEntWTempSen – Evaporator Leaving Water Temperature (LWT) sensor fault …………………….. 40 UnitOffAmbTempSen – Outside Air Temperature sensor fault …………………………………………………………… 41 OAT:Lockout – Outside Air Temperature (OAT) Lockout (only in Cooling Mode) …………………………………. 41 UnitOff CollHsngWTempSen ­ Collective Housing Water Temperature (LWT) sensor fault (Heat Pump Only) 41

5.3 Unit Rapid Stop Alarms ……………………………………………………………………………………………………………………….. 42

5.3.1 5.3.2 5.3.3 5.3.4 5.3.5 5.3.6 5.3.7

Power Failure – Power Failure (only for units with the UPS option) ……………………………………………………. 42 UnitOff EvapFreeze – Evaporator Water Temperature Low alarm ……………………………………………………… 42 UnitOff ExternalAlarm – External alarm ………………………………………………………………………………………….. 43 UnitOff PVM – PVM……………………………………………………………………………………………………………………… 43 UnitOff EvapWaterFlow – Evaporator Water Flow Loss alarm …………………………………………………………… 43 UnitOff EXVDriverComm – EXV Driver Extension Communication Error…………………………………………….. 44 UnitOff Option4BoardComm ­ Optional board 4 communication fail………………………………………………….. 44

5.4 Circuit Events …………………………………………………………………………………………………………………………………….. 44

5.4.1 5.4.2 5.4.3 5.4.4 5.4.5 5.4.6
5.4.7

Cx CompXStartFail ­ Compressor starting fail event……………………………………………………………………….. 44 Cx DischTempUnload ­ High Discharge Temperature Unload event…………………………………………………. 44 Cx EvapPressUnload ­ Low Evaporator Pressure Unload event ………………………………………………………. 45 Cx CondPressUnload ­ High Condenser Pressure Unload event ……………………………………………………… 45 Cx HighPressPd ­ High Pressure during Pumpdown event ……………………………………………………………… 45 CompxOff DischTmp CompxSenf ­ Discharge Temperature of compressor sensor fault …………………….. 46
CxStartFail – Start Fail …………………………………………………………………………………………………………………. 46

5.5 Circuit Pumpdown Stop Alarms ……………………………………………………………………………………………………………. 47

5.5.1 5.5.2 5.5.3

Cx Off DischTmpSen – Discharge Temperature Sensor fault ……………………………………………………………. 47 CxOff OffSuctTempSen – Suction Temperature Sensor fault (Heating Only) ………………………………………. 47 CxOff GasLeakage – Gas Leakage fault ………………………………………………………………………………………… 47

5.6 Circuit Rapid Stop alarms ……………………………………………………………………………………………………………………. 48

5.6.1 CxOff CondPressSen – Condensing Pressure sensor fault ………………………………………………………………. 48
5.6.2 CxOff EvapPressSen – Evaporating Pressure sensor fault ……………………………………………………………….. 48
5.6.3 CxOff DischTmpHigh – High Discharge Temperature Alarm……………………………………………………………… 48
5.6.4 CxOff CondPressHigh ­ High Condensing Pressure alarm ………………………………………………………………. 49 5.6.5 CxOff EvapPressLow – Low Pressure alarm …………………………………………………………………………………… 49
5.6.6 CxOff RestartFault ­ Restart Fault ………………………………………………………………………………………………… 50 5.6.7 CxOff MechHighPress – Mechanical High Pressure Alarm ……………………………………………………………….. 50
5.6.8 CxOff NoPressChange – No Pressure Change At Start Alarm ………………………………………………………….. 50
5.6.9 Cx FailedPumpdown – Failed Pumpdown procedure ……………………………………………………………………….. 51
5.6.10 CmpX Protection ­ Compressor Protection ……………………………………………………………………………………. 51 5.6.11 CxOff SSH LowLimit ­ SSH too low ………………………………………………………………………………………………. 51 5.6.12 CxOff LowPrRatio – Low Pressure Ratio Alarm ………………………………………………………………………………. 52
5.6.13 CxEXVDriverFailure ­ EXV Driver Failure (mono unit) …………………………………………………………………….. 52 5.6.14 CxOff BadFeedbackVlv ­ Bad Feedback from Valves Alarm (Cooling Only) ………………………………………. 52 5.6.15 Cx BadFeedbackVlvFC ­ Bad Feedback from Valves in FreeCooling mode Alarm (Cooling Only) ……….. 53 5.6.16 CxOff BadFeedbackVlvMech ­ Bad Feedback from Valves in Mechanical mode Alarm (Cooling Only) …. 53 5.6.17 CxOff BadFeedbackVlvMechPd ­ Bad Feedback from Valves in Mechanical PumpDown mode Alarm (Cooling Only)…………………………………………………………………………………………………………………………………………. 53
5.6.18 CxOff BadFeedbackVlvFCPd ­ Bad Feedback from Valves in FreeCooling PumpDown mode Alarm (Cooling Only) 54
5.6.19 CxOff BadFeedbackVlvOnTransition ­ Bad Feedback from Valves in Transition state Alarm (Cooling Only) 54

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1 SAFETY CONSIDERATIONS 1.1 General
Installation, start-up and servicing of equipment can be hazardous if certain factors particular to the installation are not considered: operating pressures, presence of electrical components and voltages and the installation site (elevated plinths and built-up up structures). Only properly qualified installation engineers and highly qualified installers and technicians, fully trained for the product, are authorized to install and start-up the equipment safely. During all servicing operations, all instructions and recommendations, which appear in the installation and service instructions for the product, as well as on tags and labels fixed to the equipment and components and accompanying parts supplied separately, must be read, understood and followed. Apply all standard safety codes and practices. Wear safety glasses and gloves.
Do not operate on a faulty fan, pump or compressor before the main switch has been shut off. Overtemperature protection is auto-reset, therefore the protected component may restart automatically if temperature conditions allow it.
In some unit a push button is placed on a door of the unit electrical panel. The button is highlighted by a red color in yellow background. A manual pressure of the emergency stop button stops all loads from rotating, thus preventing any accident which may occur. An alarm is also generated by the Unit Controller. Releasing the emergency stop button enables the unit, which may be restarted only after the alarm has been cleared on the controller.
The emergency stop causes all motors to stop, but does not switch off power to the unit. Do not service or operate on the unit without having switched off the main switch.
1.2 Before switching the unit
Before switching on the unit read the following recommendations: · When all the operations and all the settings have been carried out, close all the switchbox panels · The switchbox panels can only be opened by trained personnel · When the UC requires to be accessed frequently the installation of a remote interface is strongly recommended · LCD display of the unit controller may be damaged by extremely low temperatures (see chapter 2.4). For this reason, it is strongly recommended to never power off the unit during winter, especially in cold climates.
1.3 Avoid electrocution
Only personnel qualified in accordance with IEC (International Electrotechnical Commission) recommendations may be permitted access to electrical components. It is particularly recommended that all sources of electricity to the unit be shut off before any work is begun. Shut off main power supply at the main circuit breaker or isolator. IMPORTANT: This equipment uses and emits electromagnetic signals. Tests have shown that the equipment conforms to all applicable codes with respect to electromagnetic compatibility.
Direct intervention on the power supply can cause electrocution, burns or even death. This action must be performed only by trained persons. RISK OF ELECTROCUTION: Even when the main circuit breaker or isolator is switched off, certain circuits may still be energized, since they may be connected to a separate power source.
RISK OF BURNS: Electrical currents cause components to get hot either temporarily or permanently. Handle power cable, electrical cables and conduits, terminal box covers and motor frames with great care. ATTENTION: In accordance with the operating conditions the fans can be cleaned periodically. A fan can start at any time, even if the unit has been shut down.
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2 GENERAL DESCRIPTION

2.1 Basic Information
Microtech® IV is a system for controlling single or dual-circuit air/water- cooled liquid chillers. Microtech® IV controls compressor start-up necessary to maintain the desired heat exchanger leaving water temperature. In each unit mode it controls the operation of the condensers to maintain the proper condensation process in each circuit. Safety devices are constantly monitored by Microtech® IV to ensure their safe operation. Microtech® IV also gives access to a Test routine covering all inputs and outputs.

2.2 Abbreviations used

In this manual, the refrigeration circuits are called circuit #1 and circuit

2. The compressor in circuit #1 is labelled Cmp1.

The other in circuit #2 is labelled Cmp2. The following abbreviations are used:

A/C Air Cooled

CEWT Condenser Entering Water Temperature

CLWT Condenser Leaving Water Temperature

CP

Condensing Pressure

CSRT Condensing Saturated Refrigerant Temperature

DSH Discharge Superheat

DT

Discharge Temperature

E/M Energy Meter Module

EEWT Evaporator Entering Water Temperature

ELWT Evaporator Leaving Water Temperature

EP

Evaporating Pressure

ESRT Evaporating Saturated Refrigerant Temperature

EXV Electronic Expansion Valve

HMI Human Machine Interface

MOP Maximum operating pressure

SSH Suction SuperHeat

ST

Suction Temperature

UC

Unit controller (Microtech IV)

W/C Water Cooled

2.3 Controller Operating Limits
Operation (IEC 721-3-3): · Temperature -40…+70 °C · Restriction LCD -20… +60 °C · Restriction Process-Bus -25….+70 °C · Humidity < 90 % r.h (no condensation) · Air pressure min. 700 hPa, corresponding to max. 3,000 m above sea level
Transport (IEC 721-3-2): · Temperature -40…+70 °C · Humidity < 95 % r.h (no condensation) · Air pressure min. 260 hPa, corresponding to max. 10,000 m above sea level.

2.4 Controller Architecture
The overall controller architecture is the following: · One Microtech IV main controller · I/O extensions as needed depending on the configuration of the unit · Communications interface(s) as selected · Peripheral Bus is used to connect I/O extensions to the main controller.

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CAUTION: Maintain the correct polarity when connecting the power supply to the boards, otherwise the peripheral bus communication will not operate and the boards may be damaged.

2.5 Communication Modules
Any of the following modules can be connected directly to the left side of the main controller to allow a BAS or other remote interface to function. Up to three can be connected to the controller at a time. The controller should aut omatically detect and configure itself for new modules after booting up. Removing modules from the unit will require manually changing the configuration.

Module BacNet/IP Lon Modbus BACnet/MSTP

Siemens Part Number POL908.00/MCQ POL906.00/MCQ POL902.00/MCQ POL904.00/MCQ

Usage Optional Optional Optional Optional

3 USING THE CONTROLLER
The standard HMI consists of an inbuilt display (A) with 3 buttons (B) and a push’n’roll control (C) .

UC

A

A

B C

The keypad/display (A) consists of a 5-line by 22 character display. The function of the three buttons (B) is described

below:

Alarm status (from any page it links with the page with alarm list, alarm log and alarm snapshot if available) Back to Main Page Back to the previous level (it can be the Main Page)

The push’n’roll command (C) is used to scroll between the different menu pages, settings and data available on the HMI

for the active password level. Rotating the wheel allows to navigate between lines on a screen (page) and to increase and

decrease changeable values when editing. Pushing the wheel acts as an Enter Button and will jump from a link to the next

set of parameters.

3.1 Navigating
When power is applied to the control circuit, the controller screen will be active and display the Home screen, which can also be accessed by pressing the Menu Button. An example of the HMI screens is shown in the following picture.

Ma i n En t e r

Me n u Pa s s wo r d

1 / 11

Un i t St a t u s =

Of f : Un i t S W

Ac t i v e Se t p t =

7. 0° C

A bell ringing in the top right corner will indicate an active alarm. If the bell doesn’t move it means that the alarm has been

acknowledged but not cleared because the alarm condition hasn’t been removed. A LED will also indicate where the alarm

is located between the unit or circuits. Ma i n Me n u
En t e r Pa s s wo r d

1/

Un i t St a t u s =

Of f : Un i t S W

Ac t i v e Se t p t =

7. 0° C

The active item is highlighted in contrast, in this example the item highlighted in Main Menu is a link to another page. By

pressing the push’n’roll, the HMI will jump to a different page. In this case the HMI will jump to the Enter Password page.

En t e r Pa s s wo r d En t e r PW

2/ 2

3.2 Passwords
The HMI structure is based on access levels that means that each password will disclose all the settings and parameters allowed to that password level. Basic informations about the status can be accessed without the need to enter the password. The user UC handles two level of passwords:

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USER MAINTENANCE

5321 2526

The following information will cover all data and settings accessible with the maintenance password.

In the Enter Password screen, the line with the password field will be highlighted to indicate that the field on the right ca n

be changed. This represents a setpoint for the controller. Pressing the push’n’roll the individual field will be highlighted to

allow an easy introduction of the numeric password.

En t e r Pa s s wo r d

2/ 2

En t e r PW

5 *

The password will time out after 10 minutes and is cancelled if a new password is entered or the control powers down. Entering an invalid password has the same effect as continuing without a password. It is changeable from 3 to 30 minutes via the Timer Settings menu in the Extended Menus.

3.3 Editing
The Editing Mode is entered by pressing the navigation wheel while the cursor is pointing to a li ne containing an editable field. Pressing the wheel again cause the new value to be saved and the keypad/display to leave the edit mode and return to the navigation mode.

3.4 Basic Control System Diagnostic

Microtech IV controller, extension modules and communication modules are equipped with two status LED (BSP and BUS)

to indicate the operational status of the devices. The BUS LED indicates the status of the communication with the controller.

The meaning of the two status LED is indicated below.

Main Controller (UC)

BSP LED

Mode

Solid Green

Application running

Solid Yellow

Application loaded but not running (*) or BSP Upgrade mode active

Solid Red

Hardware Error (*)

Flashing Green

BSP startup phase. The controller needs time for starting.

Flashing Yellow

Application not loaded (*)

Flashing Yellow/Red Fail safe mode (in case that the BSP upgrade was interrupted)

Flashing Red

BSP Error (software error*)

Flashing Red/Green Application/BSP update or initialization

(*) Contact Service.

Extension modules

BSP LED

Mode

BUS LED

Mode

Solid Green

BSP running

Solid Green

Communication running, I/O working

Solid Red

Hardware Error (*)

Solid Red

Communication down (*)

Flashing Red Flashing Red/Green

BSP Error (*) BSP upgrade mode

Solid Yellow

Communication running but parameter from the application wrong or missing, or uncorrect factory calibration

Communication modules

BSP LED (same for all modules)

BSP LED

Mode

Solid Green

BPS running, communication with controller

Solid Yellow

BSP running, no communication with controller (*)

Solid Red

Hardware Error (*)

Flashing Red

BSP Error (*)

Flashing Red/Green Application/BSP update

(*) Contact Service.

BUS LED

BUS LED LON

Bacnet MSTP

Bacnet IP

Ready for

Communication. (All

Ready for

Ready for

Parameter loaded,

Communication. The

Communication. The

Solid Green Neuron configured).

BACnet Server is started. BACnet Server is started.

Doesn’t indicate a

It doesn’t indicate an

It doesn’t indicate an

communication with other active communication

active communication

devices.

Startup. The LED stays

Solid Yellow

Startup

Startup

yellow until the module receives a IP Address, therefore a link must be

established.

Solid Red

No Communication to Neuron (internal error, could be solved by downloading a new LON application)

BACnet Server down. Automatically a restart after 3 seconds are initiated.

BACnet Server down. Automatic restart after 3 seconds is initiated.

Modbus
All Communication running
Startup, or one configured channel not communicating to the Master All configured Communications down. Means no communication to the Master. The timeout can be configured. In case that the timeout is zero the timeout is disabled.

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BUS LED
Flashing Yellow

LON Communication not possible to the Neuron. The Neuron must be configured and set online over the LON Tool.

Bacnet MSTP

Bacnet IP

Modbus

3.5 Controller maintenance
The controller requires to maintain the installed battery. Every two years it’s required to replace the battery. Battery model is: BR2032 and it is produced by many different vendors. To replace the battery remove the plastic cover of the controller display us ing a screw driver as shown in the following pictures:

Be careful to avoid damages to the plastic cover. The new battery shall be placed in the proper battery holder which is highlighted in the picture, respecting the polarities indicated into the holder itself.
3.6 Optional Remote User Interface
As an option an external Remote HMI can be connected on the UC. The Remote HMI offers the same features as the inbuilt display plus the alarm indication done with a light emitting diode located below the bell button. All viewing and setpoint adjustments available on the unit controller are available on the remote panel. Navigation is identical to the unit controller as described in this manual.

MicroTech®

The Remote HMI can be extended up to 700m using the process bus connection available on the UC. With a daisy-chain connection as below, a single HMI can be connected to up to 8 units. Refer to the specific HMI manual for details.

3.7 Embedded Web Interface
The Microtech IV controller has an embedded web interface that can be used to monitor the unit when connected to a local network. It is possible to configure the IP addressing of the Microtech IV as a fixed IP of DHCP depending on the network configuration. With a common web browser a PC can connect with the unit controller entering the IP address of the controller or the host name, both visible in the “About Chiller” page accessible without entering a password. When connected, it will be required to enter a user name and a password. Enter the following credential to get access to the web interface: User Name: ADMIN Password: SBTAdmin!

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The Main Menu page will be displayed. The page is a copy of the onboard HMI and follows the same rules in terms of access levels and structure.
In addition it allows to trend log a maximum of 5 different quantities. It’s required to click on the value of the quantity to monitor and the following additional screen will become visible: Depending on the web browser and its version the trend log feature may not be visible. It’s required a web browser supporting HTML 5 like for example:
· Microsoft Internet Explorer v.11, · Google Chrome v.37, · Mozilla Firefox v.32. These software are only an example of the browser supported and the versions indicated have to be intended as minimum versions.
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4 WORKING WITH THIS UNIT
4.1 Chiller On/Off
Starting from factory setup, unit On/Off can be managed by the user using the selector Q0, placed in the electrical panel, which can switch between three positions: 0 ­ Local ­ Remote.

0

Unit is disabled

Loc (Local)

Unit is enabled to start the compressors

Rem (Remote)

Unit On/Off is managed through the “Remote On/Off” physical contact. Closed contact means unit enabled. Opened contact means unit disabled. Refer to the electrical wiring diagram, Field Wiring Connection page, to find the references about Remote On/Off contact. Generally, this contact is used to bring out from the electrical panel the on/off selector

Some chiller models can be equipped with additional selectors Q1 – Q2 used to enable or disabled specific refrigerant circuit.

0

Circuit 1 is disabled.

1

Circuit 1 is enabled.

Unit controller provides also additional software features to manage unit start/stop, that are set by default to allow unit start:
1. Keypad On/Off 2. Scheduler (Time programmed On/Off) 3. Network On/Off (optional with communication modules)
4.1.1 Keypad On/Off In the main page, scroll down until Unit Enable menu, where are available all settings to manage unit and circuits start/stop.

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Parameter Unit
Circuit #X

Range Disable Enable Scheduler Disable Enable Test

Description Unit disabled Unit enabled Unit start/stop can be time programmed for each weekday Circuit #X disabled Circuit #X enabled Circuit #X in test mode. This feature has to be used only from trained person or Daikin service

4.1.2 Scheduler and Silent mode functionalities The Scheduler function can be used when is required an automatic chiller start/stop programming. To use this function, follow below instructions:
1. Q0 selector = Local (refer to 4.1) 2. Unit Enable = Scheduler (refer to 4.1.1) 3. Controller date and time properly set (refer to 4.7)
Scheduler programming is available going in Main Page View/Set Unit Scheduler menu

For each weekday can be programmed up to six time bands with a specific operating mode. First operating mode starts at Time 1, ends at Time 2 when will start the second operating mode and so on until the latest.

Depending on unit type, different operating modes are available:

Parameter Value 1

Range Off On 1 On 2 On 1 – Silent On 2 – Silent

Description
Unit disabled
Unit enabled ­ Water setpoint 1 selected Unit enabled ­ Water setpoint 2 selected Unit enabled ­ Water setpoint 1 selected ­ Fan silent mode enabled Unit enabled ­ Water setpoint 2 selected ­ Fan silent mode enabled

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When the Fan Silent Mode function is enabled the chiller noise level is reduced decreasing the maximum speed allowed for fans. Following table reports how much maximum speed is decreased for the different unit types.

Unit noise class Normal maximum fan speed Silent mode maximum fan speed

[rpm] [rpm]

Standard

900

700

Low

900

700

Reduced

700

500

All data reported in the table, will be respected only if the chiller is operating within its operating limits.

The Fan Silent Mode function can be enabled only for units equipped with VFD fans.

4.1.3 Network On/Off Chiller On/Off can be managed also with serial protocol, if the unit controller is equipped with one or more communication modules (BACNet, Modbus or LON). In order to control the unit over the network, follow below instructions:
1. Q0 selector = Local (refer to 4.1) 2. Unit Enable = Enable (refer to 4.1.1) 3. Control Source = Network (refer to 4.5) 4. Close the contact Local/Network Switch (refer to 4.5), when required!
4.2 Water Setpoints
Purpose of this unit is to cool or to heat (in case of heat pump) the water temperature, to the setpoint value defined by the user and displayed in the main page:

The unit can work with a primary or a secondary setpoint, that can be managed as indicated below:

1. Keypad selection + Double Setpoint digital contact 2. Keypad selection + Scheduler Configuration 3. Network 4. Setpoin Reset function

As first step the primary and secondary setpoints need to be defined. From main menu, with user password, press on Setpoint.

Parameter Cool LWT 1 Cool LWT 2 Actual Reset
Heat LWT 1 Heat LWT 2 Ice LWT

Range Ranges of the Cool, Heat, Ice setpoint are reported in the IOM of every specific unit.

Description Primary cooling setpoint. Secondary cooling setpoint. This item is visible only when the Setpoint Reset function is enabled and it shows the actual reset applied to the basic setpoint Primary heating setpoint. Secondary heating setpoint. Setpoint for Ice mode.

The change between primary and secondary setpoint can be performed using the Double setpoint contact, always available in the user terminal box, or through the Scheduler function.

Double setpoint contact works as below: – Contact opened, the primary setpoint is selected – Contact closed, the secondary setpoint is selected

In order to change between primary and secondary setpoint with the Scheduler, refer to the section 4.1.2.

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When the scheduler function is enabled, the Double setpoint contact is ignored
When the operating mode Cool/Ice w/Glycol is selected, the Double Setpoint contact will be used to switch between the Cool and Ice mode, producing no change on the active setpoint
To modify the active setpoint through network connection, refer to Network control section 4.5. The active setpoint can further modified using the Setpoint Reset function as explained in the section 4.10.2.
4.3 Unit Mode
The Unit Mode is used to define if the chiller is working to produce chilled or heated water. Current mode is reported in the main page to the item Unit Mode.

Depending on the unit type, different operating modes can be selected entering, with maintenance password, in the Unit Mode menu. In the table below are listed and explained all modes.

Parameter Mode

Range Cool
Cool w/Glycol

Description Set if chilled water temperature up to 4°C is required. No glycol is generally needed in the water circuit, unless ambient temperature may reach low values. Set if chilled water temperature below 4°C is required. This operation requires proper glycol/water mixture in the evaporator water circuit.

Unit Range A/C
A/C

Cool/Ice

Set in case a dual cool/ice mode is required. The switch between the two modes is A/C

w/Glycol

performed using the contact physical Double Setpoint.

Double Setpoint opened: the chiller will work in cooling mode with the Cool LWT being

as the Active Setpoint.

Double Setpoint closed: The chiller will work in Ice mode with the Ice LWT as the

Active Setpoint.

Ice w/Glycol Set if Ice storage is required. The application requires the compressors to operate at A/C

full load until the ice bank is completed, and then to stop for at least 12 hours. In this

mode the compressor(s) will not operate at part load, but will work only in on/off mode.

The following modes allow to switch the unit between heat mode and one of the previous cool

mode (Cool, Cool w/Glycol, Ice)

Heat/Cool

Set in case a dual cool/heat mode is required. This setting implies an operation with Heat Pump

double functioning which is activated through the Cool/Heat switch on the electric box Only

· Switch COOL: The chiller will work in cooling mode with the Cool LWT as the

Active Setpoint.

· Switch HEAT: The chiller will work in heat pump mode with the Heat LWT as the

Active Setpoint.

Heat/Cool

Set in case a dual cool/heat mode is required. This setting implies an operation with A/C

w/Glycol

double functioning which is activated through the Cool/Heat switch on the electric box

· Switch COOL: The chiller will work in cooling mode with the Cool LWT as the

Active Setpoint.

· Switch HEAT: The chiller will work in heat pump mode with the Heat LWT as the

Active Setpoint

Heat/Ice

Set in case a dual Ice/Heat mode is required. This setting implies an operation with A/C

w/Glycol

double functioning which is activated through the Cool/Heat switch on the electric box

· Switch ICE: The chiller will work in cooling mode with the Ice LWT as the Active

Setpoint.

· Switch HEAT: The chiller will work in heat pump mode with the Heat LWT as the

Active Setpoint.

Test

Enables the Manual Control of the unit. The manual test feature helps in debugging A/C

and checking the operational status of actuators. This feature is accessible only with

the maintenance password in the main menu. To activate the test feature is required

to disable the Unit from the Q0 switch and change the available mode to Test.

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Parameter Energy Saving Heating Only

Range No, Yes
Not Active, Active

Description Disable/Enable of the energy saving function
Indicates if the unit can work ONLY in heating mode or not

Unit Range
Heat Pump only

Like the On/Off and setpoint control, also the unit mode can be modified from network. Refer to Network control section 4.5 for more details.

4.3.1 Heat/Cool Switch (Heat Pump Only) Starting from factory setup, Heat mode switch can be managed by the user using the selector QHP, placed in the electrical panel, which can switch between three positions: 0 ­ 1.

Chiller Unit will work in Cooling Mode

Loc (Local)

Unit will work in Heating mode

Rem

Unit Operating mode is managed through the “Remote” control through BMS communication.

(Remote)

In order to enable the Heat mode, the Unit mode must be set in “Heat/Cool” mode, and the QHP switch must be set in Loc position.

4.3.2 Energy Saving mode Some unit types provide the possibility to enable an energy saving function, that reduces the power consumption deactivating the compressors crankcase heater, when the chiller is Disabled.
This mode implies that the time needed to start the compressors, after an Off period, could be delayed until a maximum of 90 minutes.
For time critical application, the energy saving function can be disabled by the user to ensure the compressor start within 1 minute from unit On command.

4.4 Unit Status
Unit controller provides in the main page some information about chiller status. All chiller states are listed and explained below:

Parameter Unit Status

Overall status Auto:

Specific status
Wait For Load Water Recirc

Description
Unit is in Auto control. The pump is running and at least one compressor is running. Unit is in standby because the thermostatic control satisfies the active setpoint. Water pump is running in order to equalize the water temperature in the evaporator.

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Wait For Flow

Max Pulldown

Capacity Limit

Current Limit

Silent Mode

Off:

Master Disable

Ice Mode Timer

OAT Lockout

Circuits Disabled

Unit Alarm
Keypad Disable Network Disabled Unit Switch Test

Scheduler Disable Pumpdown

Unit pump is running but the flow signal still indicates a lack of flow through the evaporator. Unit thermostatic control is limiting the unit capacity as the water temperature is dropping too quickly. Demand limit has been hit. Unit capacity will not further increase. Maximum current has been hit. Unit capacity will not further increase. Unit is running and Silent Mode is enabled Unit is disabled by the Master Slave function This status can be shown only if the unit can work in Ice Mode. The unit is off because the Ice setpoint has been satisfied. Unit will remain off until the Ice Timer has expired. The unit cannot run because the Oustide Air Temperature is below the limit foreseen for the condenser temperature control system installed in this Unit. If the Unit has to run anyway, check with your local maintenance how to proceed. No circuit is available to run. All circuits can be disabled by their individual enable switch or can be disabled by a component safety condition active or can be disabled by keypad or can be all in alarms. Check the individual circuit status for further details. A unit alarm is active. Check the alarm list to see what is the active alarm inhibiting the unit to start and check if the alarm can be cleared. Refer to section 5. before proceeding. The Unit has been disabled by keypad. Check with your local maintenance if it can be enabled. Unit is disabled by Network. The Q0 selector is set to 0 or the or the Remote On/Off contact is opened. Unit mode set to Test. This mode is activated to check operability of onboard actuators and sensors. Check with the local maintenance if the Mode can be reverted to the one compatible with unit application (View/Set Unit ­ Set-Up ­ Available Modes). Unit is disabled by Scheduler programming Unit is performing the pumpdown procedure and d it will stop within few minutes

4.5 Network Control
When the unit controller is equipped with one or more communication modules the Network Control feature can be enabled, which gives the possibility to control the unit via serial protocol (Modbus, BACNet or LON). To allow unit’s control from network, follow below instructions:
1. Close the physical contact “Local/Network Switch”. Refer to unit electrical wiring diagram, Field Wiring Connection page, to find the references about this contact.
2. Go to Main Page View/Set Unit Network Control Set Controls Source = Network

Network Control menu returns all main values received from serial protocol.

Parameter Control Source
Enable Mode

Range Local Network –

Description Network control disabled Network control enabled On/Off command from network Operating mode from network

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Cool LWT Ice LWT Heat LWT FreeCooling Capacity Limit

Enable/Disable –

Cooling water temperature setpoint from network Ice water temperature setpoint from network Heating water temperature setpoint from network On/Off command from network Capacity limitation from network

Refer to communication protocol documentation for specific registers addresses and the related read/write access level.

4.6 Thermostatic Control
Thermostatic control settings allows to set up the response to temperature variations. Default settings are valid for most application, however plant specific conditions may require adjustments in order to have a smooth control or a quicker response of the unit. The control will start the first compressor if the controlled temperature is higher (Cool Mode) or lower (Heat Mode) than the active setpoint of at least a Start Up DT value, whereas other compressors are started, step by step, if the controlled temperature is higher (Cool Mode) or lower (Heat Mode) than the active setpoint (AS) of at least a Stage Up DT (SU) value. Compressors stop if performed following same procedure looking to the parameters Stage Down DT and Shut Down DT.

First compressor start

Cool Mode

Heat Mode

Controlled Temperature > Setpoint + Start Up DT Controlled Temperature < Setpoint – Start Up DT

Other compressors start Controlled Temperature > Setpoint + Stage Up DT Controlled Temperature < Setpoint – Stage Up DT

Last compressor stop Controlled Temperature < Setpoint – Shut Dn DT Controlled Temperature > Setpoint – Shut Dn DT

Other compressors stop Controlled Temperature < Setpoint – Stage Dn DT Controlled Temperature > Setpoint – Stage Dn DT

A qualitative example of compressors start-up sequence in cool mode operation is shown in the graph below.

ELWT [°C]

Compressors start-up sequence – Cool mode

SP+StartUpT

SP+StageUpT
S P

Compressors On 4

First Compressor
On

Compressor starting inhibited for maximum
pull down rate

3 2 1

Other Compressors On

Thermostatic control settings are accessible from Main PageThermostatic Control

Time
Dead band zone
Time

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Parameter Start Up DT
Shut Down DT
Stage Up DT Stage Down DT Stage Up Delay Stage Down Delay Ice Cycle Delay

Range

Description Delta temperature respect the active setpoint to start the unit (startup of first compressor) Delta temperature respect the active setpoint to stop the unit (shutdown of latest compressor) Delta temperature respect the active setpoint to start a compressor Delta temperature respect the active setpoint to stop a compressor Minimum time between the compressors startup Minimum time between the compressors shutdown Unit standby period during Ice mode operation

4.7 Date/Time
The unit controller is able to take stored the actual date and time, that are used for:
1. Scheduler 2. Cycling of standby chiller with Master Slave configuration 3. Alarms Log
Date and time can be modified going in View/Set Unit Date/Time

Parameter Time Date Day UTC Difference Daylight Saving Time: Enable

Range No, Yes

Start Month Start Week End Month End Week

NA, Jan…Dec 1st…5th week
NA, Jan…Dec 1st…5th week

Description Actual date. Press to modify. Format is hh:mm:ss Actual time. Press to modify. Format is mm/dd/yy Returns the day of the week. Coordinated universal time.
It is used to enable/disable the automatic switch of the Daylight Saving Time DayLight Saving time start month DayLight Saving time start week DayLight Saving time end month DayLight Saving time end week

Remember to check periodically the controller battery in order to maintain updated date and time even when there is no electrical power. Refer to controller maintenance section

4.8 Pumps
The UC can manage one or two water pumps. Number of pumps and their priority can be set from Main PageView/Set UnitPumps.

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Parameter Pump Control
Recirculation Timer Pump 1 Hours Pump 2 Hours

Range #1 Only

2 Only

Auto

1 Primary #2 Primary

Description Set to this in case of single pump or twin pump with only #1 operational (f.e. in case of maintenance on #2) Set to this in case of twin pump with only #2 operational (f.e. in case of maintenance on #1) Set for automatic pump start management. At each chiller start, the pump with the least number of hours will be Set to this in case of twin pump with #1 running and #2 as a backup Set to this in case of twin pump with #2 running and #1 as a backup
Minimum time required within flow switch has to in order to allow unit startup
Pump 1 running hours Pump 2 running hours

4.9 External Alarm
The External Alarm is a digital contact that can be used to communicate to the UC an abnormal condition, coming from an external device connected to the unit. This contact is located in the customer terminal box and depending on the configuration can causes a simple event in the alarm log or also the unit stop. The alarm logic associated to the contact is the following:

Contact state Alarm State

Note

Opened

Alarm

The alarm is generated if the contact remains opened for at least 5 seconds

Closed

No Alarm

The alarm is reset just the contact is closed

The configuration is performed from the Commissioning Configuration Options menu

Parameter Ext Alarm

Range Event
Rapid Stop
Pumpdown

Description Event configuration generates an alarm in the controller but takes the unit running Rapid Stop configuration generates an alarm in the controller and performs a rapid stop of the unit Pumpdown configuration generates an alarm in the controller and performs a pumpdown procedure to stop the unit.

4.10 Power Conservation
In this chapters will be explained the functions used to reduce the unit power consumption:

1. Demand Limit

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2. Setpoint Reset
4.10.1 Demand Limit The “Demand limit” function allows the unit to be limited to a specified maximum load. Capacity limit level is regulated using an external 4-20 mA signal with a linear relationship shown in the picture below. A signal of 4 mA indicates the maximum capacity available whereas a signal of 20 mA indicates the minimum capacity available. In order to enable this option, go to Main Menu Commission Unit Configuration Options and set the Demand Limit parameter to Yes.
Capacity Limit [%] Maximum Capacity

Minimum Capacity

4

20 Demand

Limit [mA]

Graph 1 Demand Limit[mA] vs Capacity Limit[%]

It is worth pointing out that it is not possible to shut down the unit using the demand limit function, but only to unload it to its minimum capacity. Note that this function does a real capacity limitation only if the unit is equipped with Screw compressors. In case of Scrol l compressors, the demand limit operates a discretization of the overall unit capacity according to the actual nu mber of compressors, and, depending on the external signal value, it enables only a subset of the total number of compressors, as shown in table below:

Number of Compressor 4 5
6

Demand Limit Signal [mA] 4< <8 8 < < 12
12 < < 16 16 < < 20 4 < < 7.2 7.2 < < 10.4 10.4 < < 13.6 13.6 < < 16.8 16.8 < < 20.0 4 < < 6.7 6.7 < < 9.3 9.3 < < 12 12 < < 14.7 14.7 < < 17.3 17.3 < < 20

Maximum number of compressors On 4 3 2 1 5 4 3 2 1 6 5 4 3 2 1

All info about this function are reported in the Main Menu Commission Unit Configuration Options Demand Limit page.

4.10.2 Setpoint Reset The “Setpoint Reset” function is able to override the chilled water temperature active setpoint when certain circumstances occur. The aim of this function is to reduce the unit energy consumption whilst maintaining the same comfort level. To this purpose, three different control strategies are available:
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· Setpoint Reset by Outside Air Temperature (OAT) · Setpoint Reset by an external signal (4-20mA) · Setpoint Reset by Evaporator T (EWT)
In order to set the desired setpoint-reset strategy, go to Main Menu Commission Unit Configuration Options and modify the Setpoint Reset parameter, according to the following table:

Parameter LWT Reset

Range No 4-20mA DT OAT

Description Setpoint reset not enabled Setpoint reset enabled by an external signal between 4 and 20mA Setpoint reset enabled by Evaporator Water Temperature Setpoint reset enabled by Outside Air Temperature

Each strategy needs to be configured (although a default configuration is available) and its parameters can be set navigating to Main Menu View/Set Unit Power Conservation Setpoint Reset.
Note that the parameters corresponding to a specific strategy will be available only once the Setpoint Reset has been set to a specific value and the UC has been restarted.
4.10.2.1 Setpoint Reset by OAT (A/C units only) When the OAT is selected as Setpoint Reset option, the LWT active setpoint(AS) is calculated applying a correction to the basic setpoint that depends on the ambient temperature (OAT) and on the current Unit Mode (Heating mode or Cooling mode). Several parameters can be configured, and they are accessible from the Setpoint Reset menu, as shown below:

Parameter Actual Reset

Default

Max Reset (MR)

5.0°C

Max Reset OAT (MROAT) 15.5°C

Start Reset OAT(SROAT) 23.8°C

Delta T
OAT Signal

Range
0.0°C10.0°C 10.0°C29.4°C 10.0°C29.4°C

Description Actual Reset shows which is the correction that will applied to the base setpoint Max Reset setpoint. It represents the maximum temperature variation that the selection of the OAT option can cause on the LWT. It represents the “threshold temperature” that correspond to the maximum setpoint variation.
It represents the “threshold temperature” of the OAT to activate the LWT setpoint reset, i.e. the LWT setpoint is overwritten only if the OAT reaches/overpasses the SROAT. Is the actual evaporator delta temperature. Entering ­ Leaving water temperature Actual outside ambient temperature
Actual input current read on the terminals Setpoint Reset

Provided the unit is set in Cooling mode (Heating mode), the more the ambient temperature drops below (goes beyond) the SROAT, the more the LWT active setpoint (AS) is increased(decreased), until the OAT reaches the MROAT limit.

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When the OAT overpasses the MROAT, the active setpoint does not increase(decrease) anymore, and it remains stable to its maximum(minimum) value, i.e. AS = LWT + MR(-MR).

Active Setpoint
LWT SP + MR
MR
LWT SP

Outside Temperature trend

Active Setpoint
LWT SP MR
LWT SP – MR

Outside Temperature trend

MROAT

SROAT

OAT

SROAT

MROAT

OAT

Graph 2 Outside Ambient Temperature vs Active Setpoint – Cooling mode(left)/ Heating mode(right)

4.10.2.2 Setpoint Reset by External 4-20Ma signal When the 4-20mA is selected as Setpoint Reset option, the LWT active setpoint(AS) is calculated applying a correction based on an external 4-20mA signal: 4 mA corresponds to 0°C correction, i.e. AS = LWT setpoint, whereas 20 mA corresponds to a correction of the Max Reset (MR) quantity, i.e. AS = LWT setpoint + MR(-MR) as shown in the following table:

Parameter Actual Reset
Max Reset (MR)
Delta T
OAT Signal
Active Setpoint LWT SP + MR

Default 5.0°C

Range 0.0°C 10.0°C

Description
Actual Reset shows which is the correction that will applied to the base setpoint Max Reset setpoint. It represents the maximum temperature variation that the selection of the 4-20mA option can cause on the LWT. Is the actual evaporator delta temperature. Entering ­ Leaving water temperature Actual outside ambient temperature
Actual input current read on the terminals Setpoint Reset
Active Setpoint
LWT SP

MR

MR

LWT SP

LWT SP – MR

4mA

20mA Signal

4mA

20mA

Graph 3 External signal 4-20mA vs Active Setpoint – Cooling mode(left)/ Heating mode(right)

Signal

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4.10.2.3 Setpoint Reset by DT When the DT is selected as Setpoint Reset option, the LWT active setpoint(AS) is calculated applying a correction based
on the temperature difference T between the leaving water temperature(LWT) and the evaporator entering(returning) water temperature (EWT). When the |T| becomes smaller than the Start Reset T setpoint(SRT), the LWT active setpoint is proportionally increased (if Cooling mode set) or decreased (if Heating mode is set) of a maximum value equal to the Max Reset(MR) parameter.

AS
Cooling
T trend
LWT SP + MR MR
LWT SP

Heating

LWT SP MR
LWT SP – MR

T trend

-SRT 0

SRT

T

Graph 4 Evap T vs Active Setpoint – Cooling mode(left)/ Heating mode(right)

Parameter Max Reset (MR)

Default 5.0°C

Range 0.0°C 10.0°C

Max Reset (MR)

5.0°C

0.0°C 10.0°C

Start Reset DT (SRT)
Delta T OAT Signal

5.0°C

0.0°C 10.0°C

Description Max Reset setpoint. It represents the maximum temperature variation that the selection of the EWT option can cause on the LWT.
Max Reset setpoint. It represents the maximum temperature variation that the selection of the DT option can cause on the LWT.
It represents the “threshold temperature” of the DT to activate the LWT setpoint reset, i.e. the LWT setpoint is overwritten only if the DT reaches/overpasses the SRT. Is the actual evaporator delta temperature. Entering ­ Leaving water temperature Actual outside ambient temperature Actual input current read on the terminals Setpoint Reset

4.11 Electrical Data
Unit controller returns main electrical values read by the energy meter Nemo D4-L or Nemo D4-Le. All data are collected in the menu Electrical Data.
Main Page View/Set Unit Electrical Data

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Parameter Average Voltage Average Current Average Power Active Power Power Factor Active Energy Frequency

Description Returns the average of the three chained voltages and links to the Voltage Data page Returns the current average and links to the Current Data page Returns the average power Returns the active power Returns the power factor Returns the active energy Returns the active frequency

4.12 Controller IP Setup
The Controller IP Setup page is located at the path Main Menu View/Set Unit Controller IP Setup.

All of the information about current MT4 IP Network settings is reported in this page, as shown in the following table:

Parameter DHCP
IP Mask Gateway PrimDNS ScndDNS Device MAC

Range On Off
xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx xxx.xxx.xxx.xxx POLxxx_xxxxxx xx-xx-xx-xx-xx-xx

Description The DHCP option is enabled. The DHCP option is disabled. The current IP address The current Subnet Mask address. The current Gateway address. The current Primary DNS address. The current Secondary DNS address. The Host Name of the MT4 controller. The MAC address of the MT4 controller.

In order to modify the MT4 IP Network configuration, do the following operations: · access the Settings menu · set the DHCP option to Off

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· modify the IP, Mask, Gateway, PrimDNS and ScndDNS addresses, if needed, taking care of the current network settings
· set Apply changes parameter to Yes to save the configuration and restart the MT4 controller.

The default internet configuration is:

Parameter IP Mask Gateway PrimDNS ScndDNS

Default Value 192.168.1.42 255.255.255.0 192.168.1.1 0.0.0.0 0.0.0.0

Note that if the DHCP is set to On and the MT4 internet configurations shows the following parameter values

Parameter IP Mask Gateway PrimDNS ScndDNS

Value 169.254.252.246 255.255.0.0 0.0.0.0 0.0.0.0 0.0.0.0

then an internet connection problem has occurred (probably due to a physical problem, like the Ethernet cable breaking).

4.13 Daikin On Site
The Daikin on Site(DoS) page can be accessed navigating through Main Menu View/Set Unit Daikin On Site.

In order to use the DoS utility, the customer has to communicate the Serial Number to Daikin company and subscribe to the DoS service. Then, from this page, it is possible to:

· Start/Stop the DoS connectivity · Check the connection status to DoS service · Enable/Disable the remote update option

according to the parameters shown into the table below.

Parameter Comm Start

Range Off Start

Description Stop the connection to DoS Start the connection to DoS

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Comm State Remote Update

IPErr Connected Enable Disable

Connection to DoS is off Connection to DoS cannot be established Connection to DoS is established and working Enable the Remote update option Disable the Remote update option

Among all the services provided by DoS, the Remote Update option allows to remotely update the software currently running on the PLC controller, avoiding an in-situ intervention of maintenance personnel. To this purpose, just set the Remote Update parameter to Enable. Otherwise, keep the parameter set to Disable.

In the unlikely event of PLC replacement, the DoS connectivity can be switched from the old PLC to the new one just communicating the current Activation Key to Daikin company.

4.14 Heat Recovery
The unit controller can handle a total or partial heat recovery option.
The heat recovery is enabled through the Q8 switch installed in the electrical panel. Some settings need to be properly set in order to match the specific plant requirements, going in Main PageView/Set UnitHeat Recovery

Parameter

Range

Description

HR State

Off

Heat recovery is disabled

Recirculation Heat recovery pump is running, but chiller fan is not regulating the heat recovery water

temperature

Regulation Heat recovery pump is running and chiller fans are regulating the heat recovery water

temperature

HR LWT

Heat recovery leaving water temperature

HR EWT

Heat recovery entering water temperature

HR EWT Sp

Heat recovery entering water temperature setpoint value

HR EWT Dif

Heat recovery

HR Lock Limit

HR Delta Sp

HR 3-Way Valve

Heat recovery 3-way valve opening percentage

HR Pumps

Heat recovery pump state

HR Pump Hours

Heat recovery pump running hours

HR C1 Enable

Heat recovery enable on circuit 1

HR C2 Enable

Heat recovery enable on circuit 2

4.15 Rapid Restart
This chiller can activate a Rapid Restart (optional) sequence in reaction to a power failure. This option allows the unit to restore the load it had before the power failure in less time, reducing the standard cycle timer. In order to Enable the Rapid Restart functionality, the customer must set to Yes the “Rapid Restart” parameter in the Rapid Restart page. The feature is configured in the factory.
The `Rapid Restart’ page can be accessed navigating through Main Menu View/Set Unit Rapid Restart.

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The “State C1/2” represents the actual state of the Rapid Restart procedure for each circuit.
Rapid restart is activated under the following conditions:
· The power failure exists for up to 180 seconds · The unit and circuit switches are ON. · No unit or circuit alarms exist. · The unit has been running in the normal Run state · The BMS Circuit Mode setpoint is set to Auto when the control source is Network · The ELWT isn’t lower than the “ELWT Setpoint + StgUpDT” · The ELWT is greater than the “ELWT Setpoint + NomEvapDT*Par_RpdRst”, where Par_RpdRst is a parameter
that can be modified.

If the power failure is more than 180 seconds, the unit will start based on the standard cycle timer without Rapid Restart. After the power restart, the timers that are used during the Rapid Restart procedure are:

Parameter Pump On 1st Compr On Full Load (6 Compr)

Timer 14s 30s 180s

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4.16 FreeCooling (Cooling Only)
The FreeCooling page can be accessed navigating through Main Menu View/Set Unit FreeCooling.

Parameter FC OPT State

Range Disable

State

Enable Off
Free Cooling Mixed

x Mode Fans Speed Command VA Valve A Open Valve A Closed

Mechanical Mechanical FreeCooling
0-100% Open Closed True False True False

Description The Option is not enabled with all the inputs necessary, or cannot run because thermodynamics issues The Option is correctly enabled Unit’s State in Off Unit State in Free Cooling mode, both Circuits run in FreeCooling Unit State in Mixed mode, one Circuit run in FreeCooling and the second run in Mechanical mode Unit State in Mechanical mode, both Circuits run in Mechanical The Circuit x is running in Mechanical mode The Circuit x is running in FreeCooling mode Percentage of fans speed controlled by FreeCooling The opening output from the controller for the VA valve The closing output from the controller for the VA valve The Valve A is opened The Valve A is NOT opened The Valve A is closed The Valve A is NOT closed

In order Enable the FreeCooling functionality, the customer must set to Enable the “Free Cooling” parameter in the FreeCooling page. The same parameter can be accessed on the Main Menu Unit Enable:

In the FreeCooling page, from View/Set Unit, the customer can visualize also some useful information, as: · “#1 Mode” and “#2 Mode”: The operating mode of each circuit; · “State”: The operating mode of the entire unit.
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In this page is possible to navigate in the pages “Valves Circuit 1” and “Valves Circuit 2”, and both contain:

Figure 1 Valves Circuit 1

Parameter State
Command V1 V1Open+V3Closed V1Closed+V3Open Command VA Valve B Open Valve B Closed

Range Off
Switching Regulation Pumpdown
Open Closed
True False True False Open Closed True False True False

Description The Circuit is in Off State The Circuit is switching the valve in FreeCooling mode The Circuit is running in FreeCooling and is regulating the Fan The Circuit is in FreeCooling Pumpdown procedure The opening output control from the controller for the V1 valve The closing output control from the controller for the V1 valve The Valve V1 is opened AND the Valve V3 is closed The Valve V1 is NOT opened AND/OR the Valve V3 is NOT closed The Valve V1 is closed AND the Valve V3 is opened The Valve V1 is NOT closed AND/OR the Valve V3 is NOT opened The opening output control from the controller for the VA valve The closing output control from the controller for the VA valve The Valve B is opened The Valve B is NOT opened The Valve B is closed The Valve B is NOT closed

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4.16.1 FreeCooling Switch
FreeCooling On/Off can be managed by the user using the selector SFC, placed in the electrical panel, which can switch between two positions: 0 ­ 1.

0

FreeCooling is disabled.

1

FreeCooling is enabled.

In order to enable the Unit to run in Free Cooling mode, both the FreeCooling Switch and the “Free Cooling” parameter, refer to 4.15, must be changed in the proper state.
4.16.2 Network On/Off
FreeCooling On/Off can be managed also with serial protocol, if the unit controller is equipped with one or more communication modules (BACNet, Modbus or LON). In order to control the unit over the network, follow below instructions:
1. SFC selector = 1 (refer to 4.15.1) 2. FreeCooling Enable = Enable (refer to 4.15) 3. Control Source = Network (refer to 4.5) 4. Close the contact Local/Network Switch (refer to 4.5), when required!

4.17 Collective Housing (Changeover Function, Heat Pump only)
It is requested the introduction of a feature that allows the automatic change of the operating mode of the unit, between heat-pump and chiller, depending on the temperature value read by a probe, that can be called “Changeover Probe”, placed in the plant.
The scope of the Changeover function is to maintain the water temperature inside a specific range, desired for the plant, for example between 30°C max and 20°C minimum. If this temperature goes above 30°C, the unit must change its operating mode in Cool, and cool the water under that value; the same if the temperature goes below 20 °C the unit must turn into Heat Pump in order to heat the water in the loop.
The thermoregulation logic follows the standard one on the ELWT probe, with also the StageUp, StageDn, StartUp and StopDn temperatures. But, for the Changeover function the software will look at the Changeover probe, to change the operating mode of the unit. Called COWT = Changeover Water Temperature,
Max Water Lim

COWT

Min Water Lim

D-EOMHP01301-20_02EN – 29/55

In order to mantain the normal logic of thermoregulation, in phases 1 -2-3 the value of Start-Up permits the chiller to turn on in cool mode and cool the water till the Shut-dn temperature, where the unit shuts off the compressor and wait the load to turn on again. Then, if the COWT < ChangeoverLowerLimit, the unit switches its operating mode into heat pump and heat the water up to Shut-Dn temperature Heat ( Heat Sp + ShutDnDt), as in the phase 4. For thermoregulation, the unit switched to off and wait till the water goes below StartUp HeatValue to turn on again the compressor, as in phase 6.
Table below reports all parameters available in Collective Housing menu when Collective Hsng option is enabled.
HMI Path : Main MenuView/Set Unit Collective Hsng

Setpoint/Sub Menu CollectiveHsng En CngOver Upper Lim CngOver Lower Lim
WaterLow Lim

Default
No 28.0 °C 20.0°C
20.0°C

WaterHigh Lim

30.0°C

Coll Hsng Sp

25.0°C

Range
No-Yes See Figure a See Figure a

Description
Enabling the changeover option Value for the Changeover Upper Limit, when the Unit switch to Cool Value for the Changeover Lower Limit, when the Unit switch to Heat Minimun water temperature that is allowed in the point where the changeover probes is placed Maximum water temperature that is allowed in the point where the changeover probes is placed Setpoint that decided the s tarting condition of the unit when is switched ON, dependig on the COWT

The Temperature of the sensor that managed the Changeover Function, is visible also in the Main Menu, with the name “Cng Over Temp”.

D-EOMHP01301-20_02EN – 30/55

4.18 Software Options
For the EWYT model, the possibility to employ a set of software options has been added to the functionality of the chiller, in according with the new Microtech 4 installed on the Unit. The Software Options do not require any additional hardware and regard communication channels and the new energy functionalities.
During the commissioning the machine is delivered with the Option Set chosen by the customer; the Password inserted is permanent and depends on the Serial Machine Number and the Option Set selected.
In order to check the current Option Set: Main MenuCommission UnitConfigurationSoftware Options

Parameter Password Option Name Option Status
The Current Password inserted activates the selected options.

Description Writable by Interface/Web
Interface Option Name Option is activated. Option is not activated

4.18.1 Changing the Password for buying new Software Options
The Option Set and the Password are updated in the Factory. If the customer wants to change its Option Set, he needs to contact the Daikin Personnel and asks for a new password.
As soon as the new password is communicated, the follow steps allow the customer to change the Option Set by himself:
1. Wait for the circuits are both OFF, then, from the Main Page, Main MenuUnit EnableUni tDisable 2. Go to Main MenuCommission UnitConfigurationSoftware Options 3. Select the Options to Activate 4. Insert the Password 5. Wait for the States of the selected options going to On 6. Apply ChangesYes (it will reboot the controller)

The Password is changeable only if the machine is working in safe conditions: both the circuits are in the State Off.
4.18.2 Inserting the Password in a Spare Controller
If the Controller is broken and/or it needs to be replaced for any reason, the customer needs to configure the Option Set with a new Password. If this replacement is scheduled, the customer can ask to Daikin Personnel for a new Password and repeat the steps in chapter 4.17.1. If there is no enough time to ask for a Password to Daikin Personnel (ex. an expected failure of the controller), a set of Free Limited Password is provided, in order not to interrupt the machine’s working. These Passwords are free and visualized in:
Main MenuCommission UnitConfigurationSoftware OptionsTemporary Passwords
D-EOMHP01301-20_02EN – 31/55

Their Use is limited up to three months: · 553489691893 ­ 3 Months Duration · 411486702597 ­ 1 Month Duration · 084430952438 ­ 1 Month Duration
It gives the customer the time enough to contact Daikin Service and insert a new unlimited password.

Parameter 553489691893 411486702597 084430952438 Mode
Temporary
Timer

Specific Status Permanent

Description Activate the Option Set for 3 Months.
Activate the Option Set for 1 Month. Activate the Option Set for 1 Month. A permanent Password is inserted. Option set can be used for unlimited time.
A temporary Password is inserted. Option set can be used depending on the password inserted. Last duration of the Option Set activated. Enabled only if the mode is Temporary

The Password is changeable only if the machine is working in safe conditions: both the circuits are in the State Off

4.18.3 Modbus MSTP Software Option
When the software option “Modbus MSTP” is activated and the controller is restarted, the communication protocol settings page can be accessed via the path:
Main MenuCommission UnitSW Modbus MSTP

D-EOMHP01301-20_02EN – 32/55

The values that can be set are the same as those found on the Modbus MSTP option page with the relative driver, and depend on the specific system where the unit is installed.
To establish the connection, the RS485 port to use is the one on the T14 terminal of the MT4 controller. 4.18.4 BACNET MSTP When the software option “BACNet MSTP” is activated and the controller is restarted, the communication protocol settings page can be accessed via the path:
Main MenuCommission UnitSW BACNet MSTP
D-EOMHP01301-20_02EN – 33/55

The values that can be set are the same as those found on the BACNet MSTP option page with the relative driver, and depend on the specific system where the unit is installed.
To establish the connection, the RS485 port to use is the one on the T14 terminal of the MT4 controller. 4.18.5 BACNET IP When the software option “BACNet IP” is activated and the controller is restarted, the communication protocol settings page can be accessed via the path:
Main MenuCommission UnitSW BACNet IP
The values that can be set are the same as those found on the BACNet MSTP option page with the re lative driver, and depend on the specific system where the unit is installed.
D-EOMHP01301-20_02EN – 34/55

The port for LAN connection to be used for BACNet IP communication is the T-IP Ethernet port, the same one used for remote control of the controller on the PC.
D-EOMHP01301-20_02EN – 35/55

5 ALARMS AND TROUBLESHOOTING
The UC protects the unit and the components from operating in abnormal conditions. Protections can be divided in preventions and alarms. Alarms can then be divided in pump-down and rapid stop alarms. Pump-down alarms are activated when the system or sub-system can perform a normal shutdown in spite of the abnormal running conditions. Rapid stop alarms are activated when the abnormal running conditions require an immediate stop of the whole system or sub -system to prevent potential damages. The UC displays the active alarms in a dedicated page and keep an history of the last 50 entries divided between alarms and acknowledges occurred. Time and date for each alarm event and of each alarm acknowledge are stored. The UC also stores alarm snapshot of each alarm occurred. Each item contains a snapshot of the running conditions right before the alarm has occurred. Different sets of snapshots are programmed corresponding to unit alarms and circuit alarms holding different information to help the failure diagnosis. In the following sections it will also be indicated how each alarm can be cleared between local HMI, Network (by any of the high-level interfaces Modbus, Bacnet or Lon) or if the specific alarm will clear automatically.
5.1 Unit Alerts
All events reported in this section does not produce a unit stop, but only a visual information and an item in the alarm log

5.1.1 BadLWTReset – Bad Leaving Water Temperature Reset Input This alarm is generated when the Setpoint Reset option has been enabled and the input to the controller is out of the admitted range.

Symptom Unit status is Run. Bell icon is moving on controller’s display. LWT Reset function cannot be used. String in the alarm list: BadLWTReset String in the alarm log: BadLWTReset String in the alarm snapshot BadLWTReset
Reset
Local HMI Network Auto

Cause
LWT reset input signal is out of range. For this warning out of range is considered to be a signal less than 3mA or more than 21mA.

Solution Check for values of input signal to the unit controller. It has to be in the allowed mA range.
Check for electrical shielding of wirings.

Check for right value of the unit’s controller output in case input signal is
into allowed range.

5.1.2 EnergyMeterComm – Energy Meter Communication Fail This alarm is generated in case of communication problems with the energy meter.

Symptom Bell icon is moving on controller’s display. String in the alarm list: EnergyMeterComm String in the alarm log:
EnergyMtrComm String in the alarm snapshot EnergyMtrComm

Cause Module has no power supply
Wrong cabling with the Unit Controller Modbus parameters not properly set

Reset
Local HMI Network Auto

Module is broken

Solution Refer to the datasheet of the specific component to see if it is correctly powered
Check if the polarity of the connections is respected.
Referring to the datasheet of the specific component to see if the modbus parameters are set correctly: Address = 20 Baud Rate =19200 kBs Parity = None Stop bits =1 Check if the display shows something and the power supply is present.

5.1.3 EvapPump1Fault – Evaporator Pump #1 Failure

This alarm is generated if the pump is started but the flow switch is not able to close within the recirculate time. This can

be a temporary condition or may be due to a broken flowswitch, the activation of circuit breakers, fuses or to a pump

breakdown.

Symptom

Cause

Solution

Unit could be ON.

Pump #1 may not be operating.

Check for problem in electrical wiring of

Bell icon is moving on controller’s display.

the pump #1.

Backup pump is used or stop of all circuits

Check that electrical breaker of pump #1

in case of pump #2 failure.

is tripped.

String in the alarm list:

If fuses are used to protect the pump,

EvapPump1Fault String in the alarm log: EvapPump1Fault

check the integrity of fuses. Check for problem in wiring connection between pump starter and unit controller.

D-EOMHP01301-20_02EN – 36/55

String in the alarm snapshot EvapPump1Fault
Reset Local HMI Network Auto

Flow Switch doesn’t operate properly

Check the water pump filter and the water circuit for obstructions. Check flow switch connection and calibration.

5.1.4 BadDemandLimit – Bad Demand Limit Input

This alarm is generated when the Demand Limit option has been enabled and the input to the controller is out of the

admitted range.

Symptom

Cause

Solution

Unit status is Run.

Demand limit input out of range Check for values of input signal to the unit

Bell icon is moving on controller’s display. For this warning out of range is considered controller. It has to be in the allowed mA

Demand Limit function cannot be used.

to be a signal less than 3mA or more than range;

String in the alarm list:

21mA.

BadDemandLimitInput String in the alarm log:

Check for electrical shielding of wirings.

BadDemandLimitInput String in the alarm snapshot BadDemandLimitInput

Check for right value of the unit’s controller output in case input signal is
into allowed range.

Reset

Notes

Local HMI

Network

Auto

Automatically clears when the signal returns in the allowed range.

5.1.5 EvapPump2Fault – Evaporator Pump #2 Failure This alarm is generated if the pump is started but the flow switch is not able to close within the recirculate time. This can be a temporary condition or may be due to a broken flowswitch, the activation of circuit breakers, fuse s or to a pump breakdown.

Symptom Unit could be ON. Bell icon is moving on controller’s display. Backup pump is used or stop of all circuits in case of pump #1 failure. String in the alarm list: EvapPump2Fault String in the alarm log:
EvapPump2Fault String in the alarm snapshot EvapPump2Fault

Cause Pump #2 may not be operating.

Reset
Local HMI Network Auto – Reset

Flow Switch doesn’t operate properly

Solution Check for problem in electrical wiring of the pump #2.
Check that electrical breaker of pump #2 is tripped. If fuses are used to protect the pump, check the integrity of fuses. Check for problem in wiring connection between pump starter and unit controller. Check the water pump filter and the water circuit for obstructions. Check flow switch connection and calibration.

5.1.6 Switch Box Temperature sensor fault This alarm is generated any time that the input resistance is out of an acceptable range.

Symptom
Unit status is On Bell icon is moving on controller’s display. Bell icon is moving on controller’s display. String in the alarm list: SwitchBoxTempSen String in the alarm log:
SwitchBoxTempSen String in the alarm snapshot SwitchBoxTempSen

Cause Sensor is broken.
Sensor is shorted. Sensor is not properly connected (open).

Reset

Local HMI

Network

Auto

Solution

Check

for

sensor

integrity.

according table and allowed kOhm (k)

range.

Check correct sensors operation

Check if sensor is shorted with a resistance measurement.
Check for absence of water or humidity on electrical contacts. Check for correct plug-in of the electrical connectors. Check for correct sensors wiring also according electrical scheme.
Notes

D-EOMHP01301-20_02EN – 37/55

5.1.7 ExternalEvent – External Event This alarm indicates that a device, whose operation is linked with this machine, is reporting a problem on the dedicated input.

Symptom
Unit status is Run. Bell icon is moving on controller’s display. String in the alarm list: External Event String in the alarm log:
ExternalEvent String in the alarm snapshot ExternalEvent

Cause
There is an external event that has caused the opening, for at least 5 seconds, of the digital input on the controller board.

Solution
Check for reasons of external event and if it can be a potential problem for a correct chiller operation.

Reset

Local HMI

Network

Auto

5.1.8 HeatRec EntWTempSen – Heat Recovery Entering Water Temperature sensor fault This alarm is generated any time that the input resistance is out of an acceptable range.

Symptom Heat Recovery is Off Bell icon is moving on controller’s display. String in the alarm list: HeatRec EntWTempSen String in the alarm log:
HeatRec EntWTempSen String in the alarm snapshot HeatRec EntWTempSen

Cause Sensor is broken.
Sensor is shorted. Sensor is not properly connected (open).

Reset

Local HMI

Network

Auto

Solution

Check

for

sensor

integrity.

according table and allowed kOhm (k)

range.

Check correct sensors operation

Check if sensor is shorted with a resistance measurement. Check for absence of water or humidity on electrical contacts. Check for correct plug-in of the electrical connectors. Check for correct sensors wiring also according electrical scheme.

5.1.9 HeatRec LvgWTempSen – Heat Recovery Leaving Water Temperature sensor fault This alarm is generated any time that the input resistance is out of an acceptable range.

Symptom
Heat Recovery is Off Bell icon is moving on controller’s display. String in the alarm list: HeatRec LvgWTempSen String in the alarm log:
HeatRec LvgWTempSen String in the alarm snapshot HeatRec LvgWTempSen

Cause Sensor is broken.
Sensor is shorted. Sensor is not properly connected (open).

Reset

Local HMI

Network

Auto

Solution

Check

for

sensor

integrity.

according table and allowed kOhm (k)

range.

Check correct sensors operation

Check if sensor is shorted with a resistance measurement.
Check for absence of water or humidity on electrical contacts.
Check for correct plug-in of the electrical connectors. Check for correct sensors wiring also according electrical scheme.

5.1.10 HeatRec FreezeAlm – Heat Recovery Water Freeze Protect alarm

This alarm is generated to indicate that the heat recovery water temperature (entering or leaving) has dropped below a

safety limit. Control tries to protect the heat exchanger starting the pump and letting the water circulate.

Symptom

Cause

Solution

Unit status is Off.

Water flow too low.

Increase the water flow.

All circuits are stopped immediately.

Bell icon is moving on controller’s display. Inlet temperature to the heat recovery is Increase the inlet water temperature.

String in the alarm list:

too low.

HeatRec FreezeAlm

Sensors readings (entering or leaving) are Check the water temperatures with a

String in the alarm log:

not properly calibrated

proper instrument and adjust the offsets

HeatRec FreezeAlm

String in the alarm snapshot

HeatRec FreezeAlm

D-EOMHP01301-20_02EN – 38/55

Reset

Local HMI

Network

Auto

5.1.11 Option1BoardComm ­ Optional board 1 communication fail This alarm is generated in case of communication problems with the AC module.

Symptom
Unit status is Off. All circuits are stopped immediately. Bell icon is moving on controller’s display. String in the alarm list: Option1BoardComm String in the alarm log: Option1BoardComm String in the alarm snapshot Option1BoardComm

Cause Module has no power supply
Module address is not properly set Module is broken

Reset

Local HMI

Network

Auto

Solution Check the power supply from the connector on the side of the module.
Check if LEDs are both green.
Check if the connector on the side is tightly inserted in the module
Check if module’s address is correct referring to the wiring diagram. Check if LED are on and both green. If BSP LED is solid red replace the module Check if power supply is ok but LEDs are both off. In this case replace the module

5.1.12 Option2BoardComm ­ Optional board 2 communication fail This alarm is generated in case of communication problems with the AC module.

Symptom
Unit status is Off. All circuits are stopped immediately. Bell icon is moving on controller’s display. String in the alarm list: Option2BoardComm String in the alarm log: Option2BoardComm String in the alarm snapshot Option2BoardComm

Cause Module has no power supply
Module address is not properly set Module is broken

Reset

Local HMI

Network

Auto

Solution Check the power supply from the connector on the side of the module.
Check if LEDs are both green.
Check if the connector on the side is tightly inserted in the module
Check if module’s address is correct referring to the wiring diagram. Check if LED are on and both green. If BSP LED is solid red replace the module Check if power supply is ok but LEDs are both off. In this case replace the module

5.1.13 Option3BoardComm ­ Optional board 3 communication fail This alarm is generated in case of communication problems with the AC module, related with the FreeCooling option.

Symptom
Unit status is Off. All circuits are stopped immediately. Bell icon is moving on controller’s display. String in the alarm list: Option3BoardComm String in the alarm log:
Option3BoardComm String in the alarm snapshot Option3BoardComm

Cause Module has no power supply
Module address is not properly set Module is broken

Reset

Local HMI

Network

Auto

Solution Check the power supply from the connector on the side of the module.
Check if LEDs are both green.
Check if the connector on the side is tightly inserted in the module
Check if module’s address is correct referring to the wiring diagram. Check if LED are on and both green. If BSP LED is solid red replace the module Check if power supply is ok but LEDs are both off. In this case replace the module

5.1.14 EvapPDSen ­ Evaporator Pressure Drop sensor fault This alarm indicates that the evaporator pressure drop transducer is not operating properly. This transducer is used only
with Pump Control VPF.

Symptom Pump speed is set with Backup value. Bell icon is moving on controller’s display.

Cause Sensor is broken.

Solution Check for sensor integrity. Check correct sensors operation

D-EOMHP01301-20_02EN – 39/55

String in the alarm list: EvapPDSen String in the alarm log: EvapPDSen String in the alarm snapshot EvapPDSen
Reset Local HMI Network Auto

Sensor is shorted. Sensor is not properly connected (open).

according information about mVolt (mV) range related to pressure values in kPa. Check if sensor is shorted with a resistance measurement. Check for correct installation of the sensor on refrigerant circuit pipe. The transducer must be able to sense the pressure through the valve’s needle. Check for absence of water or humidity on sensor electrical contacts.
Check for correct plug-in of the electrical connectors. Check for correct sensors wiring also according electrical scheme.

5.1.15 LoadPDSen ­ Load Pressure Drop sensor fault This alarm indicates that the loa pressure drop transducer is not operating properly. This transducer is used only with Pump
Control VPF.

Symptom
Pump speed is set with Backup value. Bell icon is moving on controller’s display. String in the alarm list: LoadPDSen String in the alarm log: LoadPDSen String in the alarm snapshot LoadPDSen

Cause Sensor is broken.
Sensor is shorted. Sensor is not properly connected (open).

Reset

Local HMI

Network

Auto

Solution
Check for sensor integrity. Check correct sensors operation according information about mVolt (mV) range related to pressure values in kPa. Check if sensor is shorted with a resistance measurement. Check for correct installation of the sensor on refrigerant circuit pipe. The transducer must be able to sense the pressure through the valve’s needle. Check for absence of water or humidity on sensor electrical contacts.
Check for correct plug-in of the electrical connectors. Check for correct sensors wiring also according electrical scheme.

5.2 Unit Pumpdown Alarms
All alarms reported in this section produce a unit stop performed following normal pumpdown procedure.
5.2.1 UnitOff EvpEntWTempSen – Evaporator Entering Water Temperature (EWT) sensor fault This alarm is generated any time the input resistance is out of an acceptable range.

Symptom
Unit status is Off. All circuits are stopped with a normal shutdown procedure. Bell icon is moving on controller’s display. String in the alarm list: UnitOff EvpEntWTempSen String in the alarm log: UnitOff EvpEntWTempSen String in the alarm snapshot UnitOff EvpEntWTempSen

Cause Sensor is broken.
Sensor is shorted. Sensor is not properly connected (open).

Reset

Local HMI

Network

Auto

Solution

Check

for

sensor

integrity.

according table and allowed kOhm (k)

range.

Check correct sensors operation

Check if sensor is shorted with a resistance measurement.
Check for absence of water or humidity on electrical contacts. Check for correct plug-in of the electrical connectors. Check for correct sensors wiring also according electrical scheme.

5.2.2 UnitOffLvgEntWTempSen – Evaporator Leaving Water Temperature (LWT) sensor fault This alarm is generated any time that the input resistance is out of an acceptable range.

Symptom

Cause

Solution

D-EOMHP01301-20_02EN – 40/55

Unit status is Off. All circuits are stopped with a normal shutdown procedure. Bell icon is moving on controller’s display. String in the alarm list: UnitOffLvgEntWTempSen String in the alarm log:
UnitOffLvgEntWTempSen String in the alarm snapshot UnitOffEvpLvgWTempSen

Sensor is broken.
Sensor is shorted. Sensor is not properly connected (open).

Reset

Local HMI

Network

Auto

Check

for

sensor

integrity.

according table and allowed kOhm (k)

range.

Check correct sensors operation

Check if sensor is shorted with a resistance measurement. Check for absence of water or humidity on electrical contacts. Check for correct plug-in of the electrical connectors.
Check for correct sensors wiring also according electrical scheme.

5.2.3 UnitOffAmbTempSen – Outside Air Temperature sensor fault This alarm is generated any time the input resistance is out of an acceptable range.

Symptom
Unit status is Off. All circuits are stopped with a normal shutdown precedure. Bell icon is moving on controller’s display. String in the alarm list: UnitOffAmbTempSen String in the alarm log: UnitOffAmbTempSen String in the alarm snapshot UnitOffAmbTempSen

Cause Sensor is broken.
Sensor is shorted. Sensor is not properly connected (open).

Reset

Local HMI

Network

Auto

Solution Check for sensor integrity.
Check correct sensors operation according table and allowed kOhm (k) range. Check if sensor is shorted with a resistance measurement. Check for absence of water or humidity on electrical contacts.
Check for correct plug-in of the electrical connectors. Check for correct sensors wiring also according electrical scheme.

5.2.4 OAT:Lockout – Outside Air Temperature (OAT) Lockout (only in Cooling Mode)

This alarm prevents the unit to start if the outside air temperature is too low. Purpose is to prevent low pressure trips at

startup. The limit depends on the fan regulation that is installed on the unit. By default this value is set to 10°C.

Symptom

Cause

Solution

Unit Status is OAT Lockout.

Outside ambient temperature is lower than Check the minimum outside ambient

All circuits are stopped with a normal value set into unit’s controller.

temperature value set into the unit’s

shutdown procedure.

controller.

Bell icon is moving on controller’s display.

Check if this value is in accordance with

String in the alarm list: StartInhbtAmbTempLo

chiller application, therefore check about the proper application and utilization of the

String in the alarm log:

chiller.

StartInhbtAmbTempLo

Improper operation of Outside Ambient Check for proper operation of OAT sensor

String in the alarm snapshot StartInhbtAmbTempLo

Temperature sensor.

according information about kOhm (k) range related to temperature values.

Reset

Notes

Local HMI

Network

Auto

It clears automatically with a 2.5°C of hysteresis.

5.2.5 UnitOff CollHsngWTempSen ­ Collective Housing Water Temperature (LWT) sensor fault (Heat Pump Only) This alarm is generated any time that the input resistance is out of an acceptable range. This sensor is present only when
the Collective Housing option is enabled, and when the plant hasn’t an iCM or Master/Slave control.

Symptom
Unit status is Off. All circuits are stopped with a normal shutdown procedure. Bell icon is moving on controller’s display. String in the alarm list: UnitOff CollHsngWTempSen String in the alarm log: UnitOff CollHsngWTempSen String in the alarm snapshot UnitOff CollHsngWTempSen

Cause Sensor is broken.
Sensor is shorted. Sensor is not properly connected (open).

Solution

Check

for

sensor

integrity.

according table and allowed kOhm (k)

range.

Check correct sensors operation

Check if sensor is shorted with a resistance measurement.
Check for absence of water or humidity on electrical contacts. Check for correct plug-in of the electrical connectors.

D-EOMHP01301-20_02EN – 41/55

Reset

Local HMI

Network

Auto

Check for correct sensors wiring also according electrical scheme.

5.3 Unit Rapid Stop Alarms
All alarms reported in this section produce an instantaneous stop of the unit.

5.3.1 Power Failure – Power Failure (only for units with the UPS option) This alarm is generated when the main power is Off and the unit controller is powered by the UPS.
Resolution of this fault requires a direct intervention on the power supply of this unit. Direct intervention on the power supply can cause electrocution, burns or even death. This action must be performed only by trained persons. In case of doubts contact your maintenance company.

Symptom Unit status is Off. All circuits are stopped immediately. Bell icon is moving on controller’s display. String in the alarm list: Power Fault String in the alarm log: Power Fault String in the alarm snapshot Power Fault
Reset Local HMI Network Auto

Cause Loss of one phase. Not correct sequence connection of L1,L2,L3. Voltage level on the unit’s panel is not in the allowed range (±10%).
There is a short-circuit on the unit.

Solution Check voltage level on each of the phases.
Check sequence of L1, L2, L3 connections according indication on chiller’s electrical scheme. Check that voltage level on each phases is into the allowed range that is indicated on the chiller label. Is important to check the voltage level on each phases not only with chiller not running, but mainly with chiller running from minimum capacity up to full load capacity. That’s because voltage drop can occur from a certain unit cooling capacity level, or because of certain working condition (i.e. high values of OAT); In these cases the issue can be related with the sizing of power cables. Check for correct electrical isolation condition of each unit’s circuit with a Megger tester. Notes

5.3.2 UnitOff EvapFreeze – Evaporator Water Temperature Low alarm This alarm is generated to indicate that the water temperature (entering or leaving) has dropped below a safety limit. Control tries to protect the heat exchanger starting the pump and letting the water circulate.

Symptom
Unit status is Off. All circuits are stopped immediately. Bell icon is moving on controller’s display. String in the alarm list: UnitOff EvapWaterTmpLow String in the alarm log:
UnitOff EvapWaterTmpLow String in the alarm snapshot UnitOff EvapWaterTmpLow

Cause Water flow too low.
Inlet temperature to the evaporator is too low. Flow switch is not working or no water flow.
Sensors readings (entering or leaving) are not properly calibrated.
Wrong freeze limit setpoint.

Solution Increase the water flow.
Increase the inlet water temperature.
Check the flow switch and the water pump.
Check the water temperatures with a proper instrument and adjust the offsets
The freeze limit has not been changed as a function of glycol percentage.

Reset

Local HMI

Network

Auto

D-EOMHP01301-20_02EN – 42/55

5.3.3 UnitOff ExternalAlarm – External alarm This alarm is generated to indicate that an external device whose operation is linked with this unit operation. This external device could be a pump or an inverter.

Symptom
Unit status is Off. All circuits are switched off with the normal shutdown procedure. Bell icon is moving on controller’s display. String in the alarm list: UnitOff ExternalAlarm String in the alarm log:
UnitOff ExternalAlarm String in the alarm snapshot UnitOff ExternalAlarm Reset
Local HMI Network Auto

Cause There is an external event that has caused the opening, for at least 5 seconds, of the port on the controller board.

Solution Check causes of the external event or alarm.
Check electrical wiring from unit controller to the external equipment in case of any external events or alarms have been occurred.

5.3.4 UnitOff PVM – PVM This alarm is generated in case of problems with the power supply to the chiller.
Resolution of this fault requires a direct intervention on the power supply of this unit. Direct intervention on the power supply can cause electrocution, burns or even death. This action must be performed only by trained persons. In case of doubts contact your maintenance company.

Symptom Unit status is Off. All circuits are stopped immediately. Bell icon is moving on controller’s display. String in the alarm list: UnitOff PVM String in the alarm log: UnitOff PVM String in the alarm snapshot UnitOff PVM
Reset Local HMI Network Auto

Cause Loss of one phase. Not correct sequence connection of L1,L2,L3. Voltage level on the unit’s panel is not in the allowed range (±10%).
There is a short-circuit on the unit.

Solution Check voltage level on each of the phases.
Check sequence of L1, L2, L3 connections according indication on chiller’s electrical scheme. Check that voltage level on each phases is into the allowed range that is indicated on the chiller label. Is important to check the voltage level on each phases not only with chiller not running, but mainly with chiller running from minimum capacity up to full load capacity. That’s because voltage drop can occur from a certain unit cooling capacity level, or because of certain working condition (i.e. high values of OAT); In these cases the issue can be related with the sizing of power cables. Check for correct electrical isolation condition of each unit’s circuit with a Megger tester.

5.3.5 UnitOff EvapWaterFlow – Evaporator Water Flow Loss alarm This alarm is generated in case of flow loss to the chiller to protect the machine against freezing.

Symptom Unit status is Off. All circuits are stopped immediately. Bell icon is moving on controller’s display. String in the alarm list: UnitOff EvapWaterFlow String in the alarm log: UnitOff EvapWaterFlow String in the alarm snapshot UnitOff EvapWaterFlow
Reset Local HMI Network Auto

Cause

Solution

No water flow sensed for 3 minutes Check the water pump filler and the water

continuously or water flow too low.

circuit for obstructions.

Check the flow switch calibration and adapt to minimum water flow.
Check if pump impeller can rotate freely and has no damages.
Check pumps protection devices (circuit breakers, fuses, inverters, etc.) Check if water filter is clogged.
Check flow switch connections.

D-EOMHP01301-20_02EN – 43/55

5.3.6 UnitOff EXVDriverComm – EXV Driver Extension Communication Error This alarm is generated in case of communication problems with the EEXV module.

Symptom Unit status is Off. All circuits are stopped immediately. Bell icon is moving on controller’s display. String in the alarm list: UnitOff EXVDriverComm String in the alarm log:
UnitOff EXVDriverComm String in the alarm snapshot UnitOff EXVDriverComm

Cause Module has no power supply
Module address is not properly set Module is broken

Reset

Local HMI

Network

Auto

Solution Check the power supply from the connector on the side of the module. Check if LEDs are both green.
Check if the connector on the side is tightly inserted in the module Check if module’s address is correct referring to the wiring diagram. Check if LED are on and both green. If BSP LED is solid red replace the module Check if power supply is ok but LEDs are both off. In this case replace the module

5.3.7 UnitOff Option4BoardComm ­ Optional board 4 communication fail This alarm is generated in case of communication problems with the AC module.

Symptom
Unit status is Off. All circuits are stopped immediately. Bell icon is moving on controller’s display. String in the alarm list: Option4BoardComm String in the alarm log:
Option4BoardComm String in the alarm snapshot Option4BoardComm

Cause Module has no power supply
Module address is not properly set Module is broken

Reset

Local HMI

Network

Auto

Solution Check the power supply from the connector on the side of the module. Check if LEDs are both green.
Check if the connector on the side is tightly inserted in the module
Check if module’s address is correct referring to the wiring diagram. Check if LED are on and both green. If BSP LED is solid red replace the module Check if power supply is ok but LEDs are both off. In this case replace the module

5.4 Circuit Events
5.4.1 Cx CompXStartFail ­ Compressor starting fail event This event is generated to indicate that the compressor `x’ did not start correctly.

Symptom Compressor status is Off. if the compressor was the first to switch on, the circuit is switched off with the normal shutdown procedure. Otherwise, the circuit will run with the other compressor on. String in the event list: CmpXStartFail String in the event log: CmpXStartFail String in the snapshot CmpXStartFail

Cause Compressor is blocked.
Compressor is broken.

Solution Check for compressor integrity. Check in test mode if the compressor starts manually and create Delta Pressure.
Check for compressor integrity. Check for correct compressor wiring also according with electrical scheme.

Local HMI Network Auto
5.4.2 Cx DischTempUnload ­ High Discharge Temperature Unload event This event is generated to indicate that the circuit partialized, shutting down a compressor, due to the high value of Discharge temperature detected. This is important for compressor reliability.

Symptom The Circuit reduces its capacity if the DischTmp > DischTmpUnload. If the compressor was the first to switch

Cause The circuit is working outside the compressor envelope.

Solution Check the working conditions, if the unit is working inside the unit envelope, and if the expansion valve is working well.

D-EOMHP01301-20_02EN – 44/55

on, the circuit is switched off with the normal shutdown procedure. Otherwise, the circuit will run with the other compressor on. String in the event list: Cx DischTempUnload String in the event log:
Cx DischTempUnload String in the snapshot Cx DischTempUnload

One of the compressors is damaged.

Check if the compressors are working properly, in normal conditions and without noises.

Local HMI Network Auto
5.4.3 Cx EvapPressUnload ­ Low Evaporator Pressure Unload event This event is generated to indicate that the circuit partialized, shutting down a compressor, due to the low value of Evaporator pressure detected. This is important for compressor reliability.

Symptom The Circuit reduces its capacity if the EvapPr < EvapPressUnload. If only one compressor is running, the circuit will maintain its capacity. Otherwise, the circuit will shut down one compressor each X sec, till the evaporator pressure increase. String in the event list: Cx EvapPressUnload String in the event log: Cx EvapPressUnload String in the snapshot Cx EvapPressUnload

Cause The circuit is working outside the compressor envelope.
The outside air temperature is too low (in heat mode).
The leaving water temperature is too low (Cool Mode)

Solution Check if the EXV is working well.
Check the working conditions, if the unit is working inside the unit envelope, and if the expansion valve is working well. Check if the unit is working correctly inside the unit envelope. The Circuit is near the Defrost request.
Check if the unit is working correctly inside the unit envelope.

Local HMI Network Auto
5.4.4 Cx CondPressUnload ­ High Condenser Pressure Unload event This event is generated to indicate that the circuit partialized, shutting down a compressor, due to the high value of Condensing pressure detected. This is important for compressor reliability.

Symptom
The Circuit reduces its capacity if the CondPr > CondPressUnload. If only one compressor is running, the circuit will maintain its capacity. Otherwise, the circuit will shut down one compressor each X sec, till the condenser pressure decrease. String in the event list: Cx CondPressUnload String in the event log:
Cx CondpPressUnload String in the snapshot Cx CondPressUnload

Cause The circuit is working outside the compressor envelope.
The outside air temperature is high (in cool mode). The leaving water temperature is too high (Heat Mode)

Solution
Check for ice on evaporator (Heat mode). Check the working conditions, if the unit is working inside the unit envelope, and if the expansion valve is working well. Check the correct functioning of the fans (in cool mode).
Check if the unit is working correctly inside the unit envelope.

Local HMI Network Auto
5.4.5 Cx HighPressPd ­ High Pressure during Pumpdown event This event is generated during a pumpdown procedure, to indicate that the condensing pressure goes above the unload value.

Symptom The Circuit stops the pumpdown procedure if the CondPr > CondPressUnload.
String in the event list: Cx HighPressPd

Cause The pumpdown procedure was taking too long.

Solution Check if the EXV is working well, and if it is fully close during pumpdown.
Check the working conditions, if the unit is working inside the unit envelope, and if the expansion valve is working well.

D-EOMHP01301-20_02EN – 45/55

String in the event log: Cx HighPressPd String in the snapshot Cx HighPressPd

Local HMI Network Auto

5.4.6 CompxOff DischTmp CompxSenf ­ Discharge Temperature of compressor sensor fault This alarm indicates that the discharge temperature sensor, put one for each compressor, is not operating properly.
These sensors are placed with the Option “DLT Logic” enabled.

Symptom
Compressor is switched Off. The circuit is switched off with the normal shutdown procedure only when all compressors showed the same alarm. Bell icon is moving on controller’s display. String in the alarm list: DischTmp CompxSenf String in the alarm log:
DischTmp CompxSenf String in the alarm snapshot Cx DischTmp CompxSenf

Cause Sensor is shorted.
Sensor is broken. Sensor is not properly connected (open).

Reset

Local HMI

Network

Auto

Solution
Check for sensor integrity. Check correct sensors operation according information about kOhm (k) range related to temperature values. Check if sensor is shorted with a resistance measurement. Check for correct installation of the sensor on refrigerant circuit pipe. Check for absence of water or humidity on sensor electrical contacts.
Check for correct plug-in of the electrical connectors. Check for correct sensors wiring also according with electrical scheme.

5.4.7 CxStartFail – Start Fail

This alarm is generated with a low evaporating pressure and a low saturated condensing temperature at the starting of the

circuit. This alarm is auto-reset just occurs, as the unit tries automatically to restart the circuit. At the third occurrence of

this failure a Restart Fault Alarm is generated.

Symptom

Cause

Solution

Circuit status is Off. The circuit is stopped. Bell icon is moving on controller’s display. Led on the button 2 of External HMI is blinking String in the event list: +Cx StartFailAlm String in the event log:

Low outside ambient temperature Refrigerant charge low.

Check the operating condition of the condenser-less unit
Check sight glass on liquid line to see if there is flash gas.
Measure sub-cooling to see if the refrigerant charge is correct.

Cx StartFailAlm String in the event snapshot: Cx StartFail Alm

Condensing Setpoint not correct for the Check if is necessary to increase the

application

condensing saturated temperature

setpoint

Dry cooler not correctly installed

Check that the dry cooler is safe from

strong wind

Evaporator or condensing sensor pressure Check the proper operation of the

broken or not correctly installed

pressure transducers.

Reset

Local HMI

Network

Auto

D-EOMHP01301-20_02EN – 46/55

5.5 Circuit Pumpdown Stop Alarms
All alarms reported in this section produce a circuit stop performed following normal pumpdown procedure.
5.5.1 Cx Off DischTmpSen – Discharge Temperature Sensor fault This alarm is generated to indicate that the sensor is not reading properly.

Symptom
Circuit status is Off. The circuit is switched off with the normal shutdown procedure. Bell icon is moving on controller’s display. String in the alarm list: Cx Off DischTmpSen String in the alarm log: Cx Off DischTmpSen String in the alarm snapshot Cx Off DischTmpSen

Cause Sensor is shorted.
Sensor is broken. Sensor is not properly connected (open).

Reset

Local HMI

Network

Auto

Solution Check for sensor integrity. Check correct sensors operation according information about kOhm (k) range related to temperature values. Check if sensor is shorted with a resistance measurement.
Check for correct installation of the sensor on refrigerant circuit pipe.
Check for absence of water or humidity on sensor electrical contacts. Check for correct plug-in of the electrical connectors. Check for correct sensors wiring also according with electrical scheme.

5.5.2 CxOff OffSuctTempSen – Suction Temperature Sensor fault (Heating Only) This alarm is generated to indicate that the sensor is not reading properly.

Symptom
Circuit status is Off. The circuit is switched off with the normal shutdown procedure. Bell icon is moving on controller’s display. String in the alarm list: CxOff OffSuctTempSen String in the alarm log: CxOff OffSuctTempSen String in the alarm snapshot CxOff OffSuctTempSen

Cause Sensor is shorted.
Sensor is broken. Sensor is not good connected (open).

Reset

Local HMI

Network

Auto

5.5.3 CxOff GasLeakage – Gas Leakage fault This alarm indicates a gas leakage in the compressor box.

Solution Check for sensor integrity.
Check correct sensors operation according information about kOhm (k) range related to temperature values. Check if sensor is shorted with a resistance measurement. Check for correct installation of the sensor on refrigerant circuit pipe. Check for absence of water or humidity on sensor electrical contacts. Check for correct plug-in of the electrical connectors. Check for correct sensors wiring also according with electrical scheme.

Symptom
Circuit status is Off. The circuit is switched off with the shutdown procedure performing a deep pumpdown of the circuit. Bell icon is moving on controller’s display. String in the alarm list: CxOff GasLeakage String in the alarm log:
CxOff GasLeakage String in the alarm snapshot CxOff GasLeakage

Cause Gas leakage in the compressors box (A/C units). Gas Leakage in the plant room.
Gas leakage sensor fault.

Solution Switch off the unit and perform a gas leakage test.
Check if there are leakage on the unit with a detector eventually starting suction fans to change the air in the room.
Put the sensor in open air and check that the alarm can be cleared. In case replace the sensor or disable the option before getting a new part.

Reset

Local HMI

Network

Auto

D-EOMHP01301-20_02EN – 47/55

5.6 Circuit Rapid Stop alarms
All alarms reported in this section produce an instantaneous stop of the circuit.

5.6.1 CxOff CondPressSen – Condensing Pressure sensor fault This alarm indicates that the condensing pressure transducer is not operating properly.

Symptom
Circuit status is Off. The circuit is stopped. Bell icon is moving on controller’s display. String in the alarm list: CxOff CondPressSen String in the alarm log:
CxCmp1 CondPressSen String in the alarm snapshot CxCmp1 CondPressSen

Cause Sensor is broken.
Sensor is shorted. Sensor is not properly connected (open).

Reset

Local HMI

Network

Auto

Solution Check for sensor integrity. Check correct sensors operation according information about mVolt (mV) range related to pressure values in kPa. Check if sensor is shorted with a resistance measurement.
Check for correct installation of the sensor on refrigerant circuit pipe. The transducer must be able to sense the pressure through the valve’s needle. Check for absence of water or humidity on sensor electrical contacts. Check for correct plug-in of the electrical connectors. Check for correct sensors wiring also according electrical scheme.

5.6.2 CxOff EvapPressSen – Evaporating Pressure sensor fault This alarm indicates that the evaporating pressure transducer is not operating properly.

Symptom
Circuit status is Off. The circuit is stopped. Bell icon is moving on controller’s display. String in the alarm list: CxOff EvapPressSen String in the alarm log: CxOff EvapPressSen String in the alarm snapshot CxOff EvapPressSen

Cause Sensor is broken.
Sensor is shorted. Sensor is not properly connected (open).

Reset

Local HMI

Network

Auto

Solution

Check

for

sensor

integrity.

Check correct sensors operation

according information about mVolt (mV)

range related to pressure values in kPa.

Check if sensor is shorted with a

resistance measurement.

Check for correct installation of the sensor

on refrigerant circuit pipe. The transducer

must be able to sense the pressure

through the valve’s needle.

Check for absence of water or humidity on

sensor electrical contacts.

Check for correct plug-in of the electrical

connectors.

Check for correct sensors wiring also

according electrical scheme.

5.6.3 CxOff DischTmpHigh – High Discharge Temperature Alarm This alarm indicates that the temperature at the discharge port of the compressor exceeded a maximum limit which may cause damages to the mechanical parts of the compressor.
When this alarm occurs compressor’s crankcase and discharge pipes may become very hot. Be careful when getting in contact with the compressor and discharge pipes in this condition.

Symptom

Discharge Temperature > High Discharge

Temperature

alarm

value.

Alarm cannot trigger if discharge

temperature sensor fault is active.

Bell icon is moving on controller’s display.

String in the alarm list:

CxOff DischTmpHigh

String in the alarm log:

CxOff DischTmpHigh

String in the alarm snapshot

CxOff DischTmpHigh

Cause The circuit is working outside the compressor envelope.
One of the compressors is damaged.
Discharge temperature sensor could not operate properly.

Solution Check the working conditions, if the unit is working inside the unit envelope, and if the expansion valve is working well.
Check if the compressors are working properly, in normal conditions and without noises.
Check for proper operation of the discharge temperature
Check for proper operation of the discharge temperature

D-EOMHP01301-20_02EN – 48/55

Reset
Local HMI Network Auto
5.6.4 CxOff CondPressHigh ­ High Condensing Pressure alarm This alarm is generated in case the Condensing saturated temperature rise above the Maximum condensing saturated temperature and the control is not able to compensate to this condition. In case of water cooled chillers operating at high condenser water temperature, if the Condensing saturated temperature exceeds the Maximum condenser saturated temperature, the circuit is only switched off without any notification on the screen as this condition is considered acceptable in this range of operation.

Symptom Circuit status is Off. The compressor does not load anymore or even unload, circuit is stopped. Bell icon is moving on controller’s display. String in the alarm list: CxOff CondPressHigh String in the alarm log: CxOff CondPressHigh String in the alarm snapshot CxOff CondPressHigh
Reset Local HMI Network Auto

Cause One or more condenser fans do not operate properly (A/C units).
Dirty or partially blocked condenser coil (A/C units). Inlet air temperature of the condenser is too high (A/C units).
One or more condenser fan turning in wrong direction (A/C units). Excessive charge of refrigerant into the unit.
Condensing pressure transducer could not operate properly.

Solution Check if fans protections have been activated. Check that the fans can turn freely.

Check that there is not any obstacle to the

free ejection of the air blown.

Remove any obstacle;

Clean the condenser coil using soft brush

and blower.

The air temperature measured at the inlet

of the condenser may not exceed the limit

indicated in the operational range (working

envelope) of the chiller.

Check the location where the unit is

installed and check that there are no any

short circuit of the hot-air blown from the

fans of the same unit, or even from fans of

next chillers (Check IOM for proper

installation).

Check for correct phases sequence (L1,

L2, L3) in the electrical connection of the

fans.

Check liquid sub-cooling and suction

super-heat to control indirectly the correct

charge

of

refrigerant.

If necessary recover all the refrigerant to

weight the entire charge and to control if

the value is in line with kg indication on unit

label.

Check for proper operation of the high

pressure sensor.

5.6.5 CxOff EvapPressLow – Low Pressure alarm This alarm is generated in case the evaporating pressure drops below the Low Pressure Unload and the control is not able to compensate to this condition.

Symptom
Circuit status is Off. The compressor does not load anymore or even unload, circuit is stopped immediately. Bell icon is moving on controller’s display. String in the alarm list: CxOff EvapPressLow String in the alarm log:
CxOff EvapPressLow String in the alarm snapshot CxOff EvapPressLow

Cause Transitory condition like a fan staging (A/C units). Refrigerant charge is low.
Protection limit not set to fit customer application. High Evaporator Approach.
Water flow into water heat exchanger is too low.
Evaporating pressure transducer is not working properly. EEXV is not working correctly.

Solution
Wait until the condition is recovered by EXV control Check sight glass on liquid line to see if there is flash gas. Measure sub-cooling to see if the charge is correct. Check the evaporator approach and the corresponding water temperature to evaluate the low pressure hold limit.
Clean the evaporator Check the quality of the fluid that flows into heat exchanger. Check the glycol percentage and type (ethilenic or propilenic)
Increase the water flow. Check that evaporator water pump is operating correctly providing the required water flow. Check the sensor for proper operation and calibrate the readings with a gauge. Check if pump-down can be finished for pressure limit reached;

D-EOMHP01301-20_02EN – 49/55

Reset
Local HMI Network Auto

It’s not opening enough or it’s moving in the opposite direction.
Water temperature is low

Check expansion valve movements. Check connection to the valve driver on the wiring diagram.
Measure the resistance of each winding, it has to be different from 0 Ohm. Increase inlet water temperature. Check the low pressure safeties settings.

5.6.6 CxOff RestartFault ­ Restart Fault This alarm is generated when the compressor internal protection trips

Symptom
Compressor X is Off Bell icon is moving on controller’s display. String in the alarm list: CxOff RestartFault String in the alarm log:
CxOff RestartFault String in the alarm snapshot CxOff RestartFault

Cause
This alarm is generated after 165 seconds from circuit start if the evaporating pressure is lower than the Low Pressure Unload Limit. If this alarm is triggered means that the unit is working with too low outside ambient temperature or refrigerant charge is not properly set

Solution Refer to the Low Pressure alarm.

Reset

Local HMI

Network

Auto

5.6.7 CxOff MechHighPress – Mechanical High Pressure Alarm This alarm is generated when the condenser pressure rises above the mechanical high pressure limit causing this device to open the power supply to all the auxiliary relays. This causes an immediate shutdown of compressor and all the other actuators in this circuit.

Symptom Circuit status is Off. The compressor does not load anymore or even unload, circuit is stopped. Bell icon is moving on controller’s display. String in the alarm list: CxOff MechHighPress String in the alarm log: CxOff MechHighPress String in the alarm snapshot CxOff MechHighPress
Reset Local HMI Network Auto

Cause One or more condenser fans do not operate properly(A/C units).
Dirty or partially blocked condenser coil (A/C units). Inlet air temperature of the condenser is too high (A/C units).
One or more condenser fan turning in wrong direction. Mechanical high pressure switch is damaged or not calibrated.

Solution Check if fans protections have been activated. Check that the fans can turn freely.
Check that there is not any obstacle to the free ejection of the air blown. Remove any obstacle; Clean the condenser coil using soft brush and blower. The air temperature measured at the inlet of the condenser may not exceed the limit indicated in the operational range (working envelope) of the chiller (A/C units). Check the location where the unit is installed and check that there are no any short circuit of the hot-air blown from the fans of the same unit, or even from fans of next chillers (Check IOM for proper installation). Check for correct phases sequence (L1, L2, L3) in the electrical connection of the fans. Check for proper operation of the high pressure switch.

5.6.8 CxOff NoPressChange – No Pressure Change At Start Alarm This alarm indicates that the compressor is not able to start or to create a certain minimum variation of the evaporating or condensing pressures after start.

D-EOMHP01301-20_02EN – 50/55

Symptom Circuit status is Off. The circuit is stopped. Bell icon is moving on controller’s display. String in the alarm list: CxOff NoPressChange String in the alarm log: CxOff NoPressChange String in the alarm snapshot CxOff NoPressChange
Reset Local HMI Network Auto

Cause Compressor cannot start
Compressor is turning in wrong direction.

Solution Check if the start signal is properly connected to the inverter.
Check correct phases sequence to the compressor (L1, L2, L3) according to the electrical scheme.

Refrigerant circuit is empty of refrigerant.
Not proper operation of evaporating or condensing pressure transducers.

Inverter is not properly programmed with the right direction of rotation
Check circuit pressure and presence of refrigerant. Check proper operation of evaporating or condensing pressure transducers.

5.6.9 Cx FailedPumpdown – Failed Pumpdown procedure This alarm is generated to indicate that the circuit hadn’t been able to remove all the refrigerant from the evaporator. It automatically clear as soon as the compressor stops just to be logged in the alarm history. It may not be recognized from BMS because the communication latency can give enough time for the reset. It may not even be seen on the local HMI.

Symptom Circuit status is Off. No indications on the screen String in the alarm list: -String in the alarm log: Cx FailedPumpdown String in the alarm snapshot Cx FailedPumpdown
Reset Local HMI Network Auto

Cause EEXV is not closing completely, therefore there’s “short-circuit” between high pressure side with low pressure side of the circuit.
Evaporating pressure sensor is not working properly. Compressor on circuit is internally damaged with a mechanical problems for example on internal check- valve, or on internal spirals or vanes.

Solution Check for proper operation and full closing position of EEXV. Sight glass should not show refrigerant flow after the valve is closed. Check LED on the top of the valve, C LED should be solid green. If both LED are blinking alternately the valve motor is not properly connected.
Check for proper operation of evaporating pressure sensor.
Check compressors on circuits.

5.6.10 CmpX Protection ­ Compressor Protection This alarm is generated when the compressor internal protection trips

Symptom
Compressor X is Off Bell icon is moving on controller’s display. String in the alarm list: CmpX Protection String in the alarm log:
CmpX Protection String in the alarm snapshot CmpX Protection

Cause Compressor motor PTC. Compressor discharge port PTC.

Solution Compressors is damaged
Compressor is working out of its operating limits

Reset

Local HMI

Network

Auto

5.6.11 CxOff SSH LowLimit ­ SSH too low This alarm is generated when the circuit is running with a SSH too low for a certain amount of time

Symptom
CIrcuit X is Off Bell icon is moving on controller’s display. String in the alarm list:

Cause High Evap Pressure Freezing of evaporator

Solution Restart The circuit

D-EOMHP01301-20_02EN – 51/55

SSH LowLimit String in the alarm log: SSH LowLimit String in the alarm snapshot SSH LowLimit

Reset

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Auto

5.6.12 CxOff LowPrRatio – Low Pressure Ratio Alarm

This alarm indicates that the ratio between evaporating and condensing pressure is below a limit that guarantees the

proper lubrication to compressor.

Symptom

Cause

Solution

Circuit status is Off.

Compressor is not able to develop the Check fan setpoint and settings, it could be

The circuit is stopped.

minimum compression.

too low (A/C units).

Bell icon is moving on controller’s display.

Check compressor absorbed current and

String in the alarm list:

discharge superheat. Compressor can be

CxCmp1 LowPrRatio

damaged.

String in the alarm log:

Check the correct operation of suction /

CxCmp1 LowPrRatio

delivery pressure sensors.

String in the alarm snapshot C

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