HITACHI RWM Yutaki S Series Indoor Units Instruction Manual

June 12, 2024
Hitachi

YUTAKI S SERIES
INDOOR UNITS
MODELS
RWM-(2.0-10.0)(N/R)1E
INSTRUCTION
MANUAL
INSTRUCTION MANUAL
Cooling & Heating
PMML0574 rev.2 – 02/2023

RWM Yutaki S Series Indoor Units

Specifications in this manual are subject to change without notice in order that Hitachi may bring the latest innovations to their customers.
Whilst every effort is made to ensure that all specifications are correct, printing errors are beyond Hitachi’s control; Hitachi cannot be held responsible for these errors.

CAUTION
This product shall not be mixed with general house waste at the end of its life and it shall be retired according to the appropriated local or national regulations in a environmentally correct way.
Due to the refrigerant, oil and other components contained in heat pump, its dismantling must be done by a professional installer according to the applicable regulations. Contact to the corresponding authorities for more information.

WARNING
BURST HAZARD
Do not allow air or any gas mixture containing oxygen into refriger ant cycle (i.e. piping)
RISK OF EXPLOSION
The compressor must be stopped before removing the refrigerant pipes.
All service valves must be fully closed after pumping down operation.
WARNING
This symbol displayed on the unit indicates that this appliance is filled with R32, an odourless flammable refrigerant gas with low burning velocity (A2L class pursuant to ISO 817). If the refrigerant is leaked, there is a possibility of ignition if it enters in contact with an external ignition source.
CAUTION
This symbol displayed on the unit indicates that this appliance shall be handled by authorized service personnel only, referring to the Installation Manual.
CAUTION
This symbol displayed on the unit indicates that there is relevant information included in the Operation Manual and/or Installation Manual.

MODELS CODIFICATION

Important note: Please, check, according to the model name, which is your heat pump type, how it is abbreviated and referred to in this instruction manual. This Installation and Operation Manual is only related to Indoor Units RWM-(N/R)1E combined with Outdoor Units RAS-WH(V)(N/R)P(1)(E).

INDOOR UNIT

SPLIT AIR TO WATER HEAT PUMP MODELS
1- 230V 50Hz / 3N-400V 50Hz| 3N- 400V 50Hz
Unit| Unit| Unit
RWM-2.0R1E| –| –
RWM-2.5R1E| –| –
RWM-3.0R1E| –| –
–| RWM-4.0N1E| –
–| RWM-5.0N1E| –
–| RWM-6.ON1E| –
–| –| RWM-8.0N1E
–| –| RWM-10.0N1E
| |

NOTE
Icons between brackets mean possible extra operations to the factory-supplied operations. For cooling operation, refer to the Cooling kit accessory for YUTAKI S units.
The English version is the original one; other languages are translated from English. Should any discrepancy occur between the English and the translated versions, the English version shall prevail.

GENERAL INFORMATION

No part of this publication may be reproduced, copied, filed or transmitted in any shape or form without the permission of Johnson Controls-Hitachi Air Conditioning Spain, S.A.U.
Within the policy of continuous improvement of its products, Johnson Controls- Hitachi Air Conditioning Spain, S.A.U. reserves the right to make changes at any time without prior notification and without being compelled to introducing them into products previously sold. This document may therefore have been subject to amendments during the life of the product.
Hitachi makes every effort to offer correct, up-to-date documentation. Despite this, printing errors cannot be controlled by Hitachi and are not its responsibility.
As a result, some of the images or data used to illustrate this document may not refer to specific models. No claims will be accepted based on the data, illustrations and descriptions included in this manual.

SAFETY

2.1 APPLIED SYMBOLS
During normal heat pump system design work or unit installation, greater attention must be paid in certain situations requiring particular care in order to avoid damage to the unit, the installation or the building or property.
Situations that pose a risk to the safety of those in the surrounding area or to the unit itself are clearly indicated in this manual. A series of special symbols are used to clearly identify these situations.
Pay close attention to these symbols and to the messages following them, as your safety and that of others depends on it.

This appliance is filled with R32, an odourless low burning velocity refrigerant. If the refrigerant is leaked, there is a possibility of ignition if it enters in contact with an external ignitions source.
DANGER

  • The text following this symbol contains information and instructions relating directly to your safety.
  • Not taking these instructions into account could lead to serious, very serious or even fatal injuries to you and others.

In the texts following the danger symbol you can also find information on safety procedures during unit installation.
DANGER

This symbol shows that this equipment uses a low burning velocity refrigerant. If the refrigerant is leaked, there is a possibility of ignition if it enters in contact with an external ignition source.
RISK OF EXPLOSION
The compressor must be stopped before removing the refrigerant pipes.
All service valves must be fully closed after pumping down operation.

CAUTION

  • The text following this symbol contains information and instructions relating directly to your safety.
  • Not taking these instructions into account could lead to minor injuries to you and others.
  • Not taking these instructions into account could lead to unit damage.

In the texts following the caution symbol you can also find information on safety procedures during unit installation.

NOTE

  • The text following this symbol contains information or instructions that may be of use or that require a more thorough explanation.
  • Instructions regarding inspections to be made on unit parts or systems may also be included.
Symbol Explanation
Before installation, read the installation and operation manual, and the

wiring instruction sheet.
| Before performing maintenance and service tasks, read the service manual.
| For more information, see the installer and user reference guide.

2.2 ADDITIONAL INFORMATION ABOUT SAFETY
DANGER

  • DO NOT CONNECT THE POWER SUPPLY TO THE INDOOR UNIT PRIOR TO FILLING THE SPACE HEATING CIRCUIT (AND DHW CIRCUIT IF IT WERE THE CASE) WITH WATER AND CHECKING WATER PRESSURE AND THE TOTAL ABSENCE OF ANY WATER LEAKAGE.
  • Do not pour water over the indoor unit electrical parts. If the electrical components are in contact with water a serious electrical shock will take place.
  • Do not touch or adjust the safety devices inside the air to water heat pump. If these devices are touched or adjusted, a serious accident can take place.
  • Do not open the service cover or access inside the air to water heat pump without disconnecting the main power supply.
  • In case of fire Turn OFF the main switch, put out the fire at once and contact your service contractor.
  • It must ensure that the air to water heat pump cannot operate accidentally without water neither with air inside hydraulic system.

CAUTION

  • Do not use any sprays such as insecticide, lacquer, hair spray or other flammable gases within approximately one meter from the system.
  • If installation circuit breaker or the unit fuse is often activated, stop the system and contact your service contractor.
  • Do not make service or inspections tasks by yourself. This work must be performed by a qualified service person.
  • This appliance must be used only by adult and capable people, having received the technical information or instructions to handle this appliance properly and safely.
  • Children should be supervised to ensure that they do not play with the appliance.
  • Do not let any foreign body into the water inlet and outlet piping of the air to water heat pump.

2.3 IMPORTANT NOTICE

  • The supplementary information about the purchased products is supplied in a CD-ROM, which can be found bundled with the indoor unit. In case that the CD-ROM is missing or it is not readable, please contact your Hitachi dealer or distributor.
  • PLEASE READ THE MANUAL AND THE FILES ON THE CD-ROM CAREFULLY BEFORE STARTING TO WORK ON THE INSTALLATION OF THE AIR TO WATER HEAT PUMP SYSTEM. Failure to observe the instructions for installation, use and operation described in this documentation may result in operating failure including potentially serious faults, or even the destruction of the air to water heat pump system.
  • Verify, in accordance with the manuals which appear in the outdoor and indoor units, that all the information required for the correct installation of the system is included. If this is not the case, contact your distributor.
  • Hitachi pursues a policy of continuous improvement in product design and performance. The right is therefore reserved to vary specifications without notice.
  • Hitachi cannot anticipate every possible circumstance that might involve a potential hazard.
  • This air to water heat pump has been designed for standard water heating for human beings only. Do not use this for other purposes such as for drying clothes, heating foods or for any other heating process (except swimming pool).
  • No part of this manual may be reproduced without written permission.
  • If you have any questions, contact your service contractor of Hitachi.
  • Check and make sure that the explanations of each part of this manual correspond to your air to water heat pump model.
  • Refer to the models codification to confirm the main characteristics of your system.
  • Signal words (NOTE, DANGER and CAUTION) are used to identify levels of hazard seriousness. Definitions for identifying hazard levels are provided in initial pages of this document.
  • The operation modes of these units are controlled by the unit controller.
  • This manual should be considered as a permanent part of the air to water heat pump. It gives a common description of and information for this air to water heat pump which you operate as well as for other models.
  • Keep the water temperature of the system above the freezing temperature.

DANGER
Do not use means to accelerate the defrosting process or to clean, other than those recommended by the manufacturer.

  • The appliance shall be stored in a room without continuously operating ignition sources (for example: open flames, an operating gas appliance or an operating electric heater).
  • Do not pierce or burn.
  • Be aware that refrigerants may not contain an odour

GENERAL DIMENSIONS

3.1 SERVICE SPACE
◆ RWM-(2.0-10.0)(N/R)1E H: 1200~1500 mm
Recommended unit height for proper access to the control unit panel (Unit controller).
h: 350 mm
Minimum unit height for installing the shut-off valves and the first bending pipe line.
3.2 NAME OF PARTS AND DIMENSIONAL DATA
3.2.1 RWM-(2.0-3.0)R1EHITACHI RWM Yutaki S Series Indoor Units -
DIMENSIONAL DATA

Number| Part name| Number| Part name|
---|---|---|---|---
1| Plate heat exchanger| 13| Unit controller
2| Water pump| 14| Electrical box
3| Electric water heater| 15| Switch for DHW emergency operation
4| Expansion vessel 6L| 16| Water inlet pipe connection – G 1″ Female
5| Water strainer| 17| Water outlet pipe connection – G 1″ Female
6| Air purger| 18| Refrigerant gas pipe connection – 015.88 (5/8″)
7| Water pressure sensor| 19| Refrigerant liquid pipe connection
2.0HP: 06.35 (1/41; 2.5/3.0HP: 09.52 (3/8″)
8| Safety valve| 20| Shut-down valve (Factory-supplied accessory)
9| Drain pipe for safety valve| 21| Thermistor (Water inlet pipe)
10| Expansion valve| 22| Thermistor (Water outlet pipe)
11| Manometer| 23| Thermistor (Water outlet PHEX)
12| Refrigerant strainer (x2)| 24| Thermistor (Liquid refrigerant pipe)
| 25| Thermistor (Gas refrigerant pipe)

3.2.2 RWM-(4.0-6.0)N1E

HITACHI RWM Yutaki S Series Indoor Units - Side view

Number| Part name| Number| Part name|
---|---|---|---|---
1| Plate heat exchanger| 13| Unit controller
2| Water pump| 14| Electrical box
3| Electric water heater| 15| Switch for DHW emergency operation
4| Expansion vessel 6L| 16| Water inlet pipe connection – G 1 1/4” female
5| Water strainer| 17| Water outlet pipe connection – G 1 1/4” female
6| Air purger| 18| Refrigerant gas pipe connection – ∅ 15.88 (5/8”)
7| Water pressure sensor| 19| Refrigerant liquid pipe connection – ∅ 9.52 (3/8”)
8| Safety valve| 20| Shut-down valve (Factory supplied accessory)
9| Drain pipe for safety valve| 21| Thermistor (Water inlet pipe)
10| Expansion valve| 22| Thermistor (Water outlet pipe)
11| Manometer| 23| Thermistor (Water outlet PHEX)
12| Refrigerant strainer (x2)| 24| Thermistor (Liquid refrigerant pipe)
| 25| Thermistor (Gas refrigerant pipe)

3.2.3 RWM-(8.0/10.0)N1E

HITACHI RWM Yutaki S Series Indoor Units - Front view

Number| Part name| Number| Part name|
---|---|---|---|---
1| Plate heat exchanger| 13| Unit controller
2| Water pump| 14| Electrical box
3| Electric water heater| 15| Switch for DHW emergency operation
4| Expansion vessel 6L| 16| Water inlet pipe connection – G 1 1/4” female
5| Water strainer| 17| Water outlet pipe connection – G 1 1/4” female
6| Air purger| 18| Refrigerant gas pipe connection – ∅25.4 (1”)
7| Water pressure sensor| 19| Refrigerant liquid pipe connection
8HP: ∅9.52 (3/8”)
10HP: ∅12.7 (1/2”)
8| Safety valve| 20| Shut-down valve (Factory supplied accessory)
9| Drain pipe for safety valve| 21| Thermistor (Water inlet pipe)
10| Expansion valve (x2)| 22| Thermistor (Water outlet pipe)
11| Manometer| 23| Thermistor (Water outlet PHEX)
12| Refrigerant strainer (x4)| 24| Thermistor (Liquid refrigerant pipe)
| 25| Thermistor (Gas refrigerant pipe)

REFRIGERANT AND WATER PIPING

4.1 GENERAL NOTES BEFORE PERFORMING PIPING WORK

  • Prepare locally-supplied copper pipes.
  • Select the piping size with the correct thickness and correct material able to withstand sufficient pressure.
  • Select clean copper pipes. Make sure that there is no dust or moisture inside the pipes. Blow the inside of the pipes with oxygen free nitrogen to remove any dust and foreign materials before connecting them.

NOTE
A system with no moisture or oil contamination will give maximum performance and lifecycle compared to that of a poorly prepared system. Take particular care to ensure that all copper piping is clean and dry internally.

  • Cap the end of the pipe when pipe is to be inserted through a wall hole.
  • Do not put pipes on the ground directly without a cap or vinyl tape at the end of the pipe.HITACHI RWM Yutaki S Series Indoor Units - pipe
  • If piping installation is not completed until next day or over a longer period of time, braze off the ends of the piping and charge with oxygen free nitrogen through a Schrader valve type access fitting to prevent moisture and particle contamination.
  • It is advisable to insulate the water pipes, joints and connections in order to avoid heat loss and dew condensation on the surface of the pipes or accidental injures due to excessive heat on piping surfaces.
  • Do not use insulation material that contains NH3, as it can damage copper pipe material and become a source of future leakage.
  • It is recommended to use flexible joints for the water piping inlet and outlet in order to avoid vibration transmission.
  • Refrigerant circuit and Water circuit must be performed and inspected by a licensed technician and must comply with all relevant European and national regulations.
  • Proper water pipe inspection should be performed after piping work to assure there is no water leakage in the space heating circuit.

4.2 R410A REFRIGERANT CIRCUIT
4.2.1 Refrigerant charge
The R410A refrigerant is factory charged in the outdoor unit.
NOTE
Refer to the outdoor unit Installation and operation manual to charge the R410A refrigerant.

4.2.2 Precautions in the event of gas refrigerant leaks
The installers and those responsible for drafting the specifications are obliged to comply with local safety codes and regulations in the case of refrigerant leakage.
CAUTION

  • Check for refrigerant leakage in detail. If a large refrigerant leakage occurred, it would cause difficulty with breathing or harmful gases would occur if a fire were in the room.
  • If the flare nut is tightened too hard, it may crack over time and cause refrigerant leakage.

◆ Maximum permitted concentration of HFCs
The refrigerant R410A (charged in the outdoor unit) is an incombustible and non-toxic gas. However, if leakage occurs and gas fills a room, it may cause suffocation.
The maximum permissible concentration of HFC gas according to EN378-1 is:

Refrigerant Maximum permissible concentration (kg/m3)
R410A 0.44

The minimum volume of a closed room where the system is installed to avoid suffocation in case of leakage is:

System combination Minimum volume (m3)
4 HP 7.5
5/6 HP 7.8
8 HP 11.4
10 HP 12.1

The formula used for the calculation of the maximum allowed refrigerant concentration in case of refrigerant leakage is the following:

R
— = C
V| R: Total quantity of refrigerant charged (kg)
V: Room volume (m³)
C: Refrigerant concentration
---|---

If the room volume is below the minimum value, some effective measure must be taken account after installing to prevent suffocation in case of leakage.

4.3 R32 REFRIGERANT CIRCUIT
4.3.1 General notes R32 refrigerant
This appliance is filled with R32, an odourless flammable refrigerant gas with low burning velocity (A2L class pursuant to ISO 817). If the refrigerant is leaked, there is a possibility of ignition if it enters in contact with an external ignition source.
Make sure that unit installation and refrigerant piping installation comply with applicable legislation in each country. Also, in Europe, EN378 must be complied, as it is the applicable standard.
4.3.2 Refrigerant piping
◆  Refrigerant piping length between indoor unit and outdoor unit
The unit installation and refrigerant piping should comply with the relevant local and national regulations for the designed refrigerant.
Due to R32 refrigerant and depending on final refrigerant charge amount, a minimum floor area for installation must be considered.

  • If total refrigerant charge amount <1.84kg, there are no additional minimum floor area requirements.
  • If total refrigerant charge amount ≥1.84kg, there are additional minimum floor area requirements to be checked.

New YUTAKI R32 range (2~3HP) due to low refrigerant charge amount and due to low additional charge needed, unit installation can achieve up to 30m (2/2.5HP) / 27m (3HP) without any minimum floor area requirement.

| | 2HP| 2.5HP| 3HP
---|---|---|---|---
Factory Charge| kg| 1.20| 1.30| 1.30
Charge-less piping length| m| 10| 10| 10
Additional Charge needed| g/m| 15| 15| 30
Maximum piping| m| 30| 30| 27
Maximum total refrigerant charge| kg| 1.50| 1.60| 1.81
Minimum room area requirement (Amin)| m²| No requirement is needed
Minimum piping length between outdoor unit and indoor unit (Lmin)| m| 3
Maximum height difference between indoor and outdoor unit (H)
| Outdoor unit higher than indoor unit| m| 30 (2/2.5 HP)
27 (3 HP)
| Indoor unit higher than outdoor unit| m| 20

In case of increasing more than 30m (2/2.5HP) / 27m (3HP) a minimum floor area requirement must be considered.

| | 2HP| 2.5HP| 3HP
---|---|---|---|---
Factory Charge| kg| 1.20| 1.30| 1.30
Charge-less piping length| m| 10| 10| 10
Additional Charge needed| g/m| 15| 15| 30
Maximum piping| m| 50| 50| 40
Maximum total refrigerant charge| kg| 1.80| 1.90| 2.20
Minimum room area requirement (Amin)| m²| No requirement is needed
Minimum piping length between outdoor unit and indoor unit (Lmin)| m| 3
Maximum height difference between indoor and outdoor unit (H)
| Outdoor unit higher than indoor unit| m| 30
| Indoor unit higher than outdoor unit| m| 20

NOTE
(*) In case of 3HP with piping length >27m, refrigerant piping diameter and additional charge quantity must be considered.
◆ Minimum area requirements
In case of total refrigerant amount ≥1.84 kg, the unit should be installed, operated and stored in a room with a floor area larger than the minimum criteria. Use following graphic and table to determine these minimum criteria:

Refrigerant Amount (kg) Minimum Area (m²) (H:2.2m)
1.84 28.81
1.9 30.72
2.0 34.09
2.1 37.50
2.2 41.36
2.3 45.00
2.4 49.09
2.5 53.18
2.6 57.73
2.7 61.82
2.8 66.82
2.9 71.36

HITACHI RWM Yutaki S Series Indoor Units - graphic NOTE
In case of not achieving the minimum floor area, contact with your dealer.
◆ Refrigerant piping size
Piping connection size of outdoor unit & indoor unit

| | Outdoor unit
---|---|---
Model| Piping length| Pipe Connection size
Gas pipe| Liquid pipe
2HP| 3~50m| Ø 12.7 (1/2”)| Ø 6.35 (1/4”)
2.5HP| 3~50m
3HP| 3~27m| Ø 15.88 (5/8”) ()| Ø 9.52 (3/8”) ()
27~40m| Ø 15.88 (5/8”)| Ø 9.52 (3/8”)
| | Refrigerant pipe
---|---|---
Model| Piping length| (Between OU and IU)
Gas pipe| Liquid pipe
2HP| 3~50m| Ø 12.7| Ø 6.35
2.5HP| 3~50m
3HP| 3~27m| Ø 15.88| Ø 6.35
27~40m| Ø 15.88| Ø 9.52
| | Indoor Unit
---|---|---
Model| Piping length| Pipe Connection size
Gas pipe| Liquid pipe
2HP| 3~50m| Ø 15.88 (5/8”) ()| Ø 6.35 (1/4”)
2.5HP| 3~50m| Ø 9.52 (3/8”) (
)
3HP| 3~27m| Ø 15.88 (5/8”)| Ø 9.52 (3/8”) ()
27~40m| Ø 15.88 (5/8”)| Ø 9.52 (3/8”) (
)

NOTE
(*): The refrigerant gas and liquid piping size for 2/2.5/3HP are different between outdoor and indoor unit, so refrigerant pipe adapters are required. These pipe adapters are factory supplied with the outdoor unit:

Model Pipe adapter
Gas pipe Liquid pipe
2 HP Ø15.88→Ø12.7
2.5 HP Ø15.88→Ø12.7
3.0 HP

4.3.3 Refrigerant charge
4.3.3.1 Refrigerant charge amount
The R32 refrigerant is factory charged in the outdoor unit with a refrigerant charge amount for 10 m of piping length between outdoor and indoor unit.
4.3.3.2 Refrigerant charge before shipment (W0(kg))

Outdoor unit model W0 (kg)
RAS-2WHVRP1 1.2
RAS-2.5WHVRP1 1.3
RAS-3WHVRP1 1.3

4.4 SPACE HEATING AND DHW
DANGER
Do not connect the power supply to the indoor unit prior to filling the space heating circuit (and DHW circuit if it were the case) with water and checking water pressure and the total absence of any water leakage.
4.4.1 Additional hydraulic necessary elements for space heating

Nature No. Part name
Piping connections 1 Water inlet (Space heating)
2 Water outlet (Space heating)
Factory supplied 3 Shut-off valve (factory-supplied)
Accessories 4 Water check valve

(ATW-WCV-01 accessory)
Field supplied| 5| Shut-off valve

The following hydraulic elements are necessary to correctly perform the space heating water circuit:

  • Two shut-off valves (factory supplied accessory) (3) must be installed in the indoor unit. One at the water inlet connection (1) and the other at the water outlet connection (2) in order to make easier any maintenance work.
  • A water check valve (ATW-WCV-01 accessory) (5) with 1 shut-off valve (field supplied) (4) must be connected to the water filling point when filling the indoor unit. The check valve acts as a safety device to protect the installation against back pressure, back flow and back syphon of nonpotable water into drinking water supply net.

4.4.2 Additional hydraulic necessary elementsfor DHWHITACHI RWM Yutaki
S Series Indoor Units - elements

Nature Part name
Piping connections 1 Water inlet (Space heating)
2 Water outlet (Space heating)
3 Heating coil inlet
4 Heating coil outlet
5 Water inlet (DHW)
6 Water outlet (DHW)
Factory supplied 7 Shut-off valve (factory-supplied)
Accessories 8 Domestic hot water tank (DHWT-(200/300)S-3.0H2E accessory)
9 3-way valve (ATW-3WV-01 accessory)
Field supplied 10 T-branch
11 Heating coil pipes

YUTAKI S is not factory-supplied ready for DHW operation, but it can be used for the production of DHW if the following elements are installed:

  • A domestic hot water tank (DHWT-(200/300)S-3.0H2E accessory) (8) has to be installed in combination with the indoor unit.
  • A 3-way valve (ATW-3WV-01 accessory) (9) must be connected at one point of the water outlet pipe of the installation.
  • A T-branch (field supplied) (10) must be connected at one point of the water inlet pipe of the installation.
  • Two water pipes (field supplied) (11). One pipe between 3-way valve and the heating coil inlet (3) of the DHW tank, the other one between the T-branch and the heating coil outlet (4) of the DHW tank.

Additionally, the following elements are required for the DHW circuit:

  • 1 Shut-off valve (field supplied): one shut-off valve (4) must be connected after the DHW outlet connection of the DHW tank (2) in order to make easier any maintenance work.
  • A Security water valve (Field-supplied): this accessory (3) is a pressure and temperature relief valve that must be installed as near as possible to the DHW inlet connection of the DHW tank (1). It should ensure a correct draining (5) for the discharge valve of this valve. This security water valve should provide the following:
    – Pressure protection
    – Non-return function
    – Shut-off valve
    – Filling
    – Draining

NOTE
The discharge pipe should always be open to the atmosphere, free of frost and in continuous slope to the down side in case that water leakage exists.
4.4.3 Additional hydraulic optional elements (For DHW)
In case of a recirculation circuit for the DHW circuit:

Nature Part name
Piping connections 1 Water inlet (DHW)
2 Water outlet (DHW)
Accessories 3 Water check valve  (ATW-WCV-01 accessory)
Field supplied 4 Water pump
5 Shut-off valve
  • 1 Recirculation water pump (field supplied): this water pump (3) will help to correctly recirculate the hot water to the DHW inlet.
  • 1 Water check valve (ATW-WCV-01 accessory): this Hitachi accessory (3) is connected after the recirculation water pump (4) in order to ensure the non-return of water.
  • 2 Shut-off valves (field supplied) (5): one before the recirculation water pump (4) and other after the water check valve accessory (3).

4.4.4 Requirements and recommendations for the hydraulic circuit

  • The maximum piping length depends on the maximum pressure availability in the water outlet pipe. Please check the pump curves.

  • The indoor unit is equipped with an air purger (factory supplied) at the highest location of the Indoor Unit. If this location is not the highest of the water installation, air might be trapped inside the water pipes, which could cause system malfunction. In that case additional air purgers (field supplied) should be installed to ensure no air enters the water circuit.

  • For heating floor system, the air should be purged by means of an external pump and an open circuit to avoid air bags.

  • When the unit is stopped during shut-off periods and the ambient temperature is very low, the water inside the pipes and the circulating pump may freeze, thus damaging the pipes and the water pump. In these cases, the installer shall ensure that the water temperature inside the pipes does not fall below the freezing point. In order to prevent this, the unit has a self-protection mechanism which should be activated (refer to the Service manual, “Optional functions” chapter).

  • Check that the water pump of the space heating circuit works within the pump operating range and that the water flow is over the pump’s minimum. If the water flow is below 12 litres/minute for 4.0-10.0 HP unit (6 litres/minute for 2.0/2.5/3.0HP unit),alarm is displayed on the unit.

  • An additional special water filter is highly recommended to be installed on the space heating (field installation), in order to remove possible particles remaining from brazing which cannot be removed by the indoor unit water strainer.

  • When selecting a tank for DHW operation, take into consideration the following points:
    – The storage capacity of the tank has to meet with the daily consumption in order to avoid stagnation of water.
    – Fresh water must circulate inside the DHW tank water circuit at least one time per day during the first days after the installation has been performed. Additionally, flush the system with fresh water when there is no consumption of DHW during long periods of time.
    – Try to avoid long runs of water piping between the tank and the DHW installation in order to decrease possible temperature losses.
    – lf the domestic cold water entry pressure is higher than the equipment’s design pressure (6 bar), a pressure reducer must be fitted with a nominal value of 7 bar.

  • Ensure that the installation complies with applicable legislation in terms of piping connection and materials, hygienic measures, testing and the possible required use of some specific components like thermostatic mixing valves, Differential pressure overflow valve, etc.

  • The maximum water pressure is 3 bar (nominal opening pressure of the safety valve). Provide adequate reduction pressure device in the water circuit to ensure that the maximum pressure is NOT exceeded.

  • Ensure that the drain pipes connected to the safety valve and to the air purger are properly driven to avoid water being in contact with unit components.

  • Make sure that all field supplied components installed in the piping circuit can withstand the water pressure and the water temperature range in which the unit can operate.

  • YUTAKI units are conceived for exclusive use in a closed water circuit.

  • The internal air pressure of the expansion vessel tank will be adapted to the water volume of the final installation (factory supplied with 0.1 MPa of internal air pressure).

  • Do not add any type of glycol to the water circuit.

  • Drain taps must be provided at all low points of the installation to permit complete drainage of the circuit during servicing.

4.4.5 Water quality
General recommendations for Primary (Space Heating/Cooling) and Secondary (DHW) circuit
CAUTION

  • Water quality must be according to EU council directive 98/83 EC.
  • Water should be subjected to filtration or to a softening treatment with chemicals before application as treated water.
  • It is also necessary to analyse the quality of water by checking pH, electrical conductivity, ammonia ion content, sulphur content, and others. Should the results of the analysis be not good, the use of industrial water would be recommended.
  • No antifreeze agent shall be added to the water circuit.
  • To avoid deposits of scale on the heat exchangers surface it is mandatory to ensure a high water quality with low levels of CaCO3.

Before water filling, sludge removal (for existing water networks), cleansing and rinsing (for an existing or new installations water networks) it is important to cleanse all hydraulic pipes to remove sludge and scale by using a specific designed product for cleaning central heating systems.
Also, its recommended to use a product inhibitor for protecting central heating systems against limescale and corrosion, always following manufacturer’s instructions and ensuring that the product is suitable for the material used in the water network and the YUTAKI unit.
When using chemical treatments and inhibitors always follow manufacturer’s instructions and ensure that the product is appropriate for the total water system. Using filling water that does not meet the stated quality requirements can cause a considerably reduce in service life. The responsibility will be out of Hitachi warranties.
The following water quality minimum requirement:

Parameter Parameter Value Unit
pH 6.5 to 8.5
Conductivity 10~500 µs/cm
Alkalinity 60~300 mg/l
Total Hardness 6~15 ºfH
0.6~1.5 mmol/l
60~150 mg CaCO3/I
Chlorine <50 mg CI¯/I
Sulphate <50 (mg SO4 2-/l)
Nitrate <100 mg/l (NO3)
Iron <0.2 mg/l (Fe)
TDS (Total dissolved solids) 8~400 ppm
Appearance of the water Clear and without deposits

Additional DHW Circuit recommendation
In places where possible hard water areas, to prevent and minims scale situations, it is recommended to reduce stored water temperature to a maximum of 55°C, as huge scale quantity could damage the water tank and the electrical heater.
Flush the domestic water circuit with at least 10 times its volume of water. The life of the water tank will be shorter if groundwater (spring water, well water, etc..) is used without treatment which can lead to the corrosion of the tank. The water must not be aggressive or encrusting at any time. The result of calculating the Langelier Index should be between +/- 0.5.
In installation locations where the result of Langelier Index calculation are out of the expected value with a tendency to corrosive water, it is recommended to install the active anode accessory (ATW-CP-05 only available for YUTAKI H Combi version).
In the regions where the water is very hard (or out of requirements values) or where the result of Langelier Index calculation are out of expected value with a tendency to hard water, it is recommended fitting a softener system. Please ensure that softener system will be capable of providing effective protection against corrosion. It is recommended to install the active anode accessory (ATW-CP-05 only available for YUTAKI H Combi version).
As DHW Tank water is being used for storing drinking water, this water has to be in accordance with national regulations and Hitachi’s quality minimum requirements. The use of softeners, active anodes or others protective systems will not bring a derogation from Hitachi’s provided warranty.

4.4.6 Water filling

  1. Check that a water check valve (ATW-WCV-01 accessory) with a shut-off valve (field supplied) is connected to the water filling point (water inlet connection) for filling the space heating hydraulic circuit (see “4.4 Space heating and DHW”).

  2. Make sure all the valves are open (water inlet/outlet shut-off valves and the rest of valves of the space heating installation components).

  3. Ensure that the air purgers of the indoor unit and installation are open (turn the indoor unit air purger twice at least).

  4. Check that the drain pipes connected to the safety valve (and to the drain pan in case of installing the “Cooling kit” accessory) are correctly connected to the general draining system. The safety valve is later used as an air purging device during the water filling procedure.

  5. Fill the space heating circuit with water until the pressure displayed on the manometer reaches approximately 1.8 bar.
    NOTE
    While the system is being filled with water, it is highly recommended to operate the safety valve manually so as to help with the air purging procedure.

  6. Remove as much air from inside the water circuit as possible through the indoor air purger and other air vents in the installation (fan coils, radiators…).

  7. Start the air purge procedure test. There are two modes (Manual or Automatic) which helps in case of installations with heating and DHW operation:
    a. Manual: Start and stop the unit manually using the unit controller (Run/Stop button) and also using the DSW4 pin 2 of the PCB1 (ON: Forced to derive to DHW coil;
    OFF: Forced to derive to space heating).
    b. Automatic: Select the air purge function using the user controller. When the automatic air purge function is running, the pump speed and the position of the 3-way valve (space heating or DHW) are automatically changed.HITACHI
RWM Yutaki S Series Indoor Units - pump speed

  8. If a little quantity of air is still remaining in the water circuit, it will be removed by the automatic air purger of the indoor unit during the first hours of operation. Once the air in the installation has been removed, a reduction of water pressure in the circuit is very likely to occur. Therefore, additional water should be filled until water pressure returns to an approximate level of 1.8 bar.

NOTE

  • The indoor unit is equipped with an automatic air purger (factory supplied) at the highest location of the indoor unit. Anyway, if there are higher points in the water installation, air might be trapped inside water pipes, which could cause system  alfunction. In that case, additional air purgers (field supplied) should be installed to ensure no air enters into the water circuit. The air vents should be located at points which are easily accessible for servicing.
  • The water pressure indicated on the indoor unit manometer may vary depending on the water temperature (the higher temperature, the higher pressure). Nevertheless, it must remain above 1 bar in order to prevent air from entering the circuit.
  • Fill in the circuit with tap water. The water in the heating installation must comply with EN directive 98/83 EC. Non-sanitary controlled water is not recommended (for example, water from wells, rivers, lakes, etc.)
  • The maximum water pressure is 3 bar (nominal opening pressure of the safety valve). Provide adequate reduction pressure device in the water circuit to ensure that the maximum pressure is NOT exceeded.
  • For heating floor system, air should be purged by means of an external pump and an open circuit to prevent the formation of air pockets.
  • Check carefully for leaks in the water circuit, connections and circuit elements.

ELECTRICAL AND CONTROL SETTINGS

5.1 GENERAL CHECK

  • Make sure that the following conditions related to power supply installation are satisfied:
    – The power capacity of the electrical installation is large enough to support the power demand of the YUTAKI system (outdoor unit + indoor unit + DHW tank (if apply)).
    – The power supply voltage is within ±10% of the rated voltage.
    – The impedance of the power supply line is low enough to avoid any voltage drop of more than 15% of the rated voltage.

  • Following the Council Directive 2014/30/EU, relating to electromagnetic compatibility, the table below indicates the Maximum permitted system impedance Zmax at the interface point of the user’s supply, in accordance with EN61000-3-11.

Model Power supply Operation mode *Zmax (Ω) ()**
RWM-(2.0-3.0)R1E 1~ 230V 50Hz Without electric heaters
With electric heater
With DHW tank heater
With electric and DHW tank heaters 0.28
3N~ 400V Without electric heaters
With electric heater
With DHW tank heater
With electric and DHW tank heaters
RWM-(4.0-6.0)N1E 1~ 230V Without electric heaters
With electric heater 0.28
With DHW tank heater
With electric and DHW tank heaters 0.19
3N~ 400V Without electric heaters
With electric heater
With DHW tank heater
With electric and DHW tankhe aters
RWM-(8.0/10.0)N1E 3N~ 400V Without electric heaters
With electric heater
With DHW tank heater
With electric and DHW tank heaters

NOTE
The data corresponding to DHW tank heater is calculated in combination with the domestic hot water tank accessory “DHWT-(200/300)S-3.0H2E”.

  • The status of Harmonics for each model, regarding compliance with EN 61000-3-2 and EN 61000-3-12, is as follows:
    Status regarding compliance with EN 61000-3-2 and EN 61000-3-12| Models
    ---|---
    Equipment complying with EN 61000-3-2| RWM-2.0R1E
    RWM-2.5R1E
    RWM-3.0R1E
    RWM-4.0N1E (3N~)
    RWM-5.0N1E (3N~)
    RWM-6.0N1E (3N~)
    RWM-8.0N1E
    RWM-10.0N1E
    Equipment complying with EN 61000-3-12| RWM-4.0N1E (1~)
    RWM-5.0N1E (1~)
    RWM-6.0N1E (1~)
  • Check to ensure that existing installation (mains power switches, circuit breakers, wires, connectors and wire terminals) already complies with the national and local regulations.
  • The use of the DHW tank heater is disabled as setting. If it is desired to enable the DHW tank heater operation during normal indoor unit operation, adjust the DSW4 pin 3 of the PCB1 to the ON position and use the adequate protections. Refer to the section “5.6 Setting of DIP switches and RSW switches” for the detailed information.

5.2 SYSTEM WIRING DIAGRAM
Connect the units according to the following electric diagram:

TB :Terminal board :Field wiring
CB : Circuit breaker :Field-supplied
ELB :Earth leakage breaker 1,2 : Outdoor-Indoor communication
:Internal wiring

HITACHI RWM Yutaki S Series Indoor Units - Outdoor 5.3 WIRING SIZE AND MINIMUM REQUIREMENTS OF THE PROTECTION DEVICES
CAUTION

  • Check to ensure that the field supplied electrical components (mains power switches, circuit breakers, wires, connectors and wire terminals) have been properly selected according to the electrical data indicated on this chapter and they comply with  national and local codes. If it is necessary, contact with your local authority in regards to standards, rules, regulations, etc.
  • Use a dedicated power circuit for the indoor unit. Do not use a power circuit shared with the outdoor unit or any other appliance.
    Use wires which are not lighter than the polychloroprene sheathed flexible cord (code designation 60245 EN 57).

Model| Power supply| Operation mode| Max current (A)| Power supply cables| Transmitting cables| CB (A)| poles/A/mA)
ELB (nº of
---|---|---|---|---|---|---|---
EN 60335-1| EN 60335-1
RWM-(2.0-3.0)R1E| 1~ 230V 50Hz| Without electricheaters| 0.6| 2 x 0.75 mm² + GND| 2 x 0.75 mm2| 5| 2/40/30
With electric heater| 14.9| 2 x 2.5 mm² + GND| 16
With DHW tank heater| 14.9| 2 x 2.5 mm² + GND| 16
With electric and DHW tank heaters| 29.3| 2 x 6.0 mm² + GND| 32
3N~ 400V 50Hz| Without electric heaters| 0.6| 4 x 0.75 mm² + GND| 5| 4/40/30
With electric heater| 5.3| 4 x 2.5 mm² + GND| 10
With DHW tank heater| 14.9| 4 x 4.0 mm² + GND| 20
With electric and DHW tank heaters| 19.7| 4 x 6.0 mm² + GND| 25
RWM-(4.0-6.0)N1E| 1~ 230V 50Hz| Without electric heaters| 0.6| 2 x 0.75 mm² + GND| 5| 2/40/30
With electric heater| 29.3| 2 x 6.0 mm² + GND| 32
With DHW tank heater| 14.9| 2 x 2.5 mm² + GND| 16
With electric and DHW tank heaters| 43.6| 2 x 10.0 mm² + GND| 50| 2/63/30
3N~ 400V 50Hz| Without electric heaters| 0.6| 4 x 0.75 mm² + GND| 5| 4/40/30
With electric heater| 10.1| 4 x 2.5 mm² + GND| 15
With DHW tank heater| 14.9| 4 x 2.5 mm² + GND| 15
With electric and DHW tank heaters| 24.5| 4 x 6.0 mm² + GND| 25
RWM-(8.0/10.0)N1E| 3N~ 400V 50Hz| Without electric heaters| 0.6| 4 x 0.75 mm²

  • GND| 5| 4/40/30
    With electric heater| 14.9| 4 x 4.0 mm² + GND| 20
    With DHW tank heater| 15.0| 4 x 4.0 mm² + GND| 20
    With electric and DHW tank heaters| 29.2| 4 x 10.0 mm² + GND| 30

NOTE
The data corresponding to DHW tank heater is calculated in combination with the domestic hot water tank accessory “DHWT-(200/300)S-3.0H2E”.
CAUTION

  • Ensure specifically that there is an Earth Leakage Breaker (ELB) installed for the units (outdoor and indoor unit).
  • If the installation is already equipped with an Earth Leakage Breaker (ELB), ensure that its rated current is large enough to hold the current of the units (outdoor and indoor unit).

NOTE

  • Electric fuses can be used instead of magnetic Circuit Breakers (CB). In that case, select fuses with similar rated values as the CB.
  • The Earth Leakage Breaker (ELB) mentioned on this manual is also commonly known as Residual Current Device (RCD) or Residual Current Circuit Breaker (RCCB).
  • The Circuit Breakers (CB) are also known as Thermal-Magnetic Circuit Breakers or just Magnetic Circuit Breakers (MCB).

5.4 TRANSMISSION WIRING BETWEEN OUTDOOR AND INDOOR UNIT

  • The transmission is wired to terminals 1-2.
  • The H-LINK II wiring system requires only two transmission cables that connect the indoor unit and the outdoor unit.
  • Use twist pair wires (0.75 mm²) for operation wiring between outdoor unit and indoor unit. The wiring must consist of 2-core wires (Do not use wire with more than 3 cores).
  • Use shielded wires for intermediate wiring to protect the units from noise interference, with a length of less than 300 m and a size in compliance with local codes.
  • In the event that a conduit tube for field-wiring is not used, fix rubber bushes to the panel with adhesive.

CAUTION
Ensure that the transmission wiring is not wrongly connected to any live part that could be damaged the PCB.

5.5 OPTIONAL INDOOR UNIT WIRING (ACCESSORIES)

HITACHI RWM Yutaki S Series Indoor Units - ACCESSORIES

Mark Part name Description

TERMINAL BOARD 1 (TB1)
N| 1 230V 50Hz| 3N 400V 50Hz| Main power supply connection
L1
L2| –
L3
TERMINAL BOARD 2 (T82)
1| H LINK commutation| The H-LINK transmission has to be done between the indoor unit and the terminals 1-2 of either outdoor unit, ATW-RTU or any other central device.
2
3| H-LINK communication for remote control switch| Terminals for the connection of the YUTAKI unit controller.
4
5| DHW tank’s thermistor| The DI-IW sensor is used to control the temperature of the domestic hot water tank.
6| Common thermistor| Common terminal for themtistor.
7| Thermistor for water outlet temperature of second cycle| The sensor is used for the second temperature control and should be positioned after the mixing valve and the circulation pump.
8| Thermistor for water outlet temperature after hydraulic separator| Water sensor for hydraulic separator, buffer tank or boiler combination.
9| Common thermistor| Common terminal for thermistors.
10| Thermistor for swimming pool water temperature| The sensor is used for the swimming pool temperature control and should be positioned inside plate heat exchanger of the swimming pool.
11| Thermistor for second ambient temperature| The sensor is used for the second ambient temperature control and it should be positioned outdoors.
12| Earth| Earth connection for the 3 way valve and water pump
13| Common line| Terminal Line common for input 1 and input 2.
14| Input 1 (Demand ON/OFF) ()| The air to water heat pump system has been designed to allow the connection of a remote thermostat to effectively control your home’s temperature. Depending on the room temperature, the thermostat will tum the split air to water heat pump system ON and OFF.
15| Input 2 (ECO mode) (
)| Available signal which allows to reduce the water setting temperature of circuit 1. circuit 2 or both.
16| Common line| Terminal Line common for inputs 3, 4, 5.6. 7.
17| Input 3 (Swimming pool) (•)| Only for swimming pool installations: It is neoessay to connect an external input to the air to water heat pump to provide signal when the water pump of swimming pool is ON.
18| Input 4 (Solar) (1| Available input for Solar combination with Domestic Hot Water Tank.
19| Input 5 (Smart function) (1| For the connection of an extemal tariff switch device to switch OFF the heat pump during peak electricity demand period. Depending on the setting, the heat pump or DHWT will be blocked when signal is open/closed.
20| Input 6 (DHW boost) ()| Available input for an instantaneous heating of the domestic hot water of the tank.
21| Input 7 (Power meter)| The measuring of the real power consumption can be done connecting an external power meter. The number of pulses of the power meter is a variable which must be set By this, every pulse input is added into corresponding operation mode (Heating. Cooling. DHW Operation). Two possible options:
– One power meter for all installation (IU+OU).
– Two separated power meters (one for IU and one for OU).
22| Aquastat security for circuit 1 (WP1)| Terminals intended for the connection of the Aquastat security accessory (ATW-AQT-01) for controlling water temperature of the circuit 1.
23
24(C)| Mixing valve close| When a mixing system is required for a second temperature control, these outputs are necessary to control the mixing valve.
25(o)| Mixing valve open
26(N)| N Common
27(L)| Water Pump 2 (WP2)| When there is a second temperature application, a secondary pump is the circulating pump for the secondary heating circuit.
28| Auxiliary power| Power supply for ATWATU and central device
29
30(N)| Electrical Heater DHW Output| If DHW tank contains an electric heater, the air to water heat pump can activate it if the heat pump cannot achieve the required DHW temperature by itself.
31(L)
32(C)| Common line| Common terminal for the 3-way valve for DHW tank.
33(L)| 3-way valve for DHW tank| The air to water heat pump can be used to heat DHW. This output will be on when DHW is activated.
---|---|---
34(N)| N common| Neutral terminal common for 3-way valve of DHW tank and outputs 1 and 2.
35(L)| Output 1 (3-way valve for swimming pool) (
)| The air to water heat pump can be use to heat swimming pool. This output will be ON when swimming pool is activated.
36(L)| Output 2 (Water pump 3 (WP3)) ()| When there is a hydraulic separator or buffer tank, additional water pump (WP3) is needed.
37| Output 3 (Auxiliary boiler or electric heater) (
)| The boiler can be used to alternate with the heat pump when the heat pump cannot achieve the required temperature by it self.
A water electric heater (as accessory) can be used to provide the additional heating required on the coldest days of the year.
38
39| Output 4 (Solar) (*)| Output for solar combination with Domestic Hot Water Tank.
40

NOTE
(*): Inputs and outputs explained in the table are the factory-set options. By means of the unit controller, some other inputs and outputs functions can be configured and used. Please, refer to the Service Manual for detailed information.

5.6 SETTING OF DIP SWITCHES AND RSW SWITCHES
5.6.1 Location of DIP switches and rotary switches

HITACHI RWM Yutaki S Series Indoor Units - rotary
switches

5.6.2 Function of DIP switches and rotary switches

NOTE

  • The mark “■” indicates the dip switches positions.
  • No mark “■” indicates pin position is not affected.
  • The figures show the settings before shipment or after selection.
  • “Not used” means that the pin must not be changed. A malfunction might occur if changed.

CAUTION
Before setting dip switches, first turn the power supply OFF and then set the position of dip switches. If the switches are set without turning the power supply OFF, the contents of the setting are invalid.

◆ DSW1: Additional setting 0
Factory setting. No setting is required.

Factory setting|
---|---

NOTE
In case of installing the “Cooling kit” accessory, set the pin 4 of DSW1 to ON in order to enable the cooling operation.

◆ DSW2: Unit capacity setting
No setting is required.

HITACHI RWM Yutaki S Series Indoor Units - No setting

◆ DSW3: Additional setting 1

1-step heater for 3-phase unit|
---|---
Setting before shipment|

◆ DSW4: Additional setting 2

Setting before shipment|
---|---
DHW defrost|
Heater forced OFF|
Unit and installation pipes antifreeze protection|
Standard / ECO water pump operation|
Electric heater or boiler emergency mode|
DHW tank’s heater operation|
DHW 3-way valve and expansion valve forced ON|

CAUTION

  • Never turn all DSW4 dip switch pins ON. If this happens, the software of the unit will be removed.
  • Never activate “Heater Forced OFF” and “Electric heater or boiler emergency mode” at the same time.

DSW5: Additional setting 3

In the cases where the outdoor unit is installed into a location where its own outdoor ambient temperature sensor can not give a suitable temperature measurement to the system, it is available the 2nd outdoor ambient temperature sensor as accessory. By means of DSW1&2 setting, the preferable sensor for each circuit can be selected.

Factory setting|
---|---
Outdoor unit sensor for circuits 1 and 2.|
Outdoor unit sensor for circuit 1; Auxiliary sensor for circuit 2.|
Auxiliary sensor for circuit 1; Outdoor unit sensor for circuit 2.|
Auxiliary sensor instead of outdoor unit sensor for both circuits.|
Use the maximum temperature value between Two3 (boiler / heater thermistor) and Two (water outlet thermistor) for water control|

DSW6: Not used

Factory setting (Do not change)|
---|---

DSW7: Additional setting 4

Factory setting|
---|---
Compatibility with ATW-RTU-04 (When cooling mode operation is needed)|

DSW18: Not used

Factory setting
(Do not change)|
---|---

◆ DSW15 & RSW2: Not used

Factory setting (Do not change)| |
---|---|---

◆ DSW16 & RSW1: Not used

Factory setting (Do not change)| |
---|---|---

◆ SSW1: Remote/Local

Factory setting
(Remote operation)|
---|---
Local operation| Remote
Local

◆ SSW2: Heat/Cool

Factory setting (Heat operation)|
---|---
Cool and Heat operation in case of Local| Remote
Local

5.6.3 LED indication

Name Colour Indication
LED1 Green Power indication
LED2 Red Power indication
LED3 Red Heat pump operation (thermo ON/OFF)
LED4 Yellow Alarm (flickering with 1 sec interval)
LED5 Green Not used
LED6 Yellow H-LINK transmission
LED7 Yellow H-LINK remote control transmission

UNIT INSTALLATION

6.1 GENERAL NOTES
6.1.1 Selection of the installation location

The indoor unit of the split system with air to water heat pump must be installed following these basic requirements:

  • The indoor unit is intended to be installed in an indoor place and for ambient temperatures ranging 5~30°C. The ambient temperature around the indoor unit must be >5°C to prevent water from freezing.
  • The unit is prepared to be wall mounted (wall bracket is factory supplied), so make sure that selected wall is flat and is made of a non-combustible surface, strong enough for supporting the indoor unit weight.
  • Be sure to maintain the recommended servicing space for future unit servicing and guarantee enough air circulation around the unit (See “3.1 Service space” section).
  • Take into account that two shut-off valves (factory supplied) must be installed at the indoor unit inlet/outlet connections.
  • Keep water draining provisions. The safety valve and the air purge are provided with a drain pipe which are located at the bottom side of the unit.
  • If the event of installing the “Cooling kit” accessory, the installer is responsible for proper installation and draining.
  • Protect the indoor unit against the entry of small animals (like rats) which could making contact with the wires, the drain pipe, electrical parts and may damage unprotected parts, and at the worst, a fire will occur.
  • Install it in a no-frost environment.
  • Do not install the indoor unit in a location with very high humidity.
  • Do not install the indoor unit where electromagnetic waves are directly radiated to the electrical box.
  • Install the unit in a place where in case of water leakage, any damage to the installation space cannot be produced.
  • Install noise filter when the power supply emits harmful noises.
  • To avoid fire or explosion, do not install the unit in a flammable environment.
  • The air to water heat pump must be installed by a service technician. The installation must comply with local and European regulations.
  • Try to avoid to put any objects or tools above the indoor unit.

6.1.2 Unpacking
All units are supplied with a wooden base, packed by a cardboard box and plastic bag.
Firstly to unpack it, place the unit on the assembly area as close as possible to its final installation location, to avoid damages in transport. Two persons are required.

  1. Cut the strapping bands and remove the adhesive tapes.
  2. Remove the carton assembly and then the plastic bag around the unit.
  3. Unscrew the 4 screws which fix the unit to the wooden base.
  4. Remove the indoor unit from the wooden base and place it carefully on the floor, as near as possible to its final location.

CAUTION

  • Be careful with the Installation and Operation manual and with the factory-supplied accessories box located besides the unit.
  • Two people are required when lifting because of the weight of the unit.

6.1.3 Factory-supplied indoor unit components

Accessory Image Qty. Purpose

Shut-off valve (2-3HP: 1″)
(4-10HP: 1-1/4″)| | 2| To make easier the installation work in the space heating water inlet/outlet connections.
For a better servicing.
Gasket| | 4| Two gaskets for each space heating connections (inlet/outlet)
Wall support| | 1| For hanging the unit on the wall
CD-ROM| | 1| With the detailed Installation and operation manual
Instruction manual| | 1| Basic instructions for the installation of the device.
Instruction manual| | 1| Additional safety manual for R32 refrigerant air conditioner and heat pump according to IEC 60335-2-40:2018
Declaration of conformity| –| 1| –

NOTE

  • The previous accessories are supplied inside the packing assembly (besides the indoor unit).
  • Additional refrigerant piping (field supplied) for connections to outdoor unit needs to be available.
  • If some of these accessories are not packed with the unit or any damage to the unit is detected, please contact your dealer.

6.1.4 Indoor unit main parts (Descriptions)

| Part|
---|---|---
1| Indoor unit service cover
2| Unit controller frame
3| Unit controller
4| Piping connections

6.2 REMOVING THE COVERS
If it is necessary to access to the indoor unit components, please follow these operations.

6.2.1 Removing the indoor unit service cover

NOTE
The indoor unit service cover needs to be removed for any task inside the indoor unit.

  1. Remove the screw which fixes the service cover.
  2. Slide the service cover slightly upward and remove it pulling to back.

CAUTION

  • Pay attention of no falling off the service cover.
  • Take care when removing service cover; the parts inside the unit could be hot.

6.2.2 Removing indoor unit electrical box

DANGER

  • Disconnect the unit from the power supply before touching any of the parts in order to avoid an electrical shock.
  • Do not touch the switch for DHW tank heater operation when handling the electrical box. Keep the position of this switch in factory setting position (“Automatic” operation).

Remove the electrical box cover
RWM-(2.0-3.0) R1E

  1. Remove the indoor unit service cover as explained above.
  2. Unscrew the 2 front screws of the electrical box cover and then, rotate it.

HITACHI RWM Yutaki S Series Indoor Units - electrical box
1

CAUTION
Take care with the electrical box components in order to avoid damaging it.

RWM-(4.0-10.0)N1E

  1. Remove the indoor unit service cover as explained above.
  2. Unscrew the 4 front screws of the electrical box cover and then, remove it.

HITACHI RWM Yutaki S Series Indoor Units - service cover
1

CAUTION
Take care with the electrical box components in order to avoid damaging it.

6.3 INSTALLATION OF INDOOR UNIT

NOTE
Please, try to perform all this procedure following all the steps in the exact order in which they are presented below.

Installation procedure

  1. Wall mounting procedure
  2. Space heating pipes connection
  3. Drain pipes connection
  4. Refrigerant piping connection
  5. Power and transmission wiring connection
  6. Cover assembly
  7. Test and check

6.3.1 Wall mounting procedure

  1. Fix the wall support (factory-supplied accessory) to the wall using appropriate plugs and screws. Make sure that the wall support is completely levelled.
  2. Hang the indoor unit on the wall support (at least two persons are required in order to lift the unit because of its weight).
  3. Fix the indoor unit at the bottom side using the 4 screws which had been previously removed during the unpacking procedure.

HITACHI RWM Yutaki S Series Indoor Units - during

6.3.2 Space heating pipes connection
The unit is factory supplied with two shut-off valves which have to be connected to the water inlet / outlet connections. With these shut-off valves it is very practical to connect the indoor unit to the heating system by using the factory supplied gaskets just below the valves (G 1” connection for 2.0-3.0HP; G 1-1/4” connection for 4.0-10.0HP). Then, the space heating installation can be carried out.

HITACHI RWM Yutaki S Series Indoor Units - Shut-off
valves

6.3.3 Drain pipes connection

For a correct drainage, connect the drain pipe for the safety valve to the general draining system.

NOTE

  • The safety valve is activated when water pressure reaches 3 bars.
  • Drain taps must be provided at all low points of the installation to permit complete drainage of the circuit during servicing.

6.3.4 Refrigerant piping connection
Make the connection of refrigerant pipes respecting the considerations indicated in the CD-ROM factory-supplied with the unit.

6.3.5 Power and transmission wiring connection
◆ Safety instructions

NOTE
Check the requirements and recommendations in the chapter “5 Electrical and control settings”.

DANGER

  • Do not connect the power supply to the indoor unit prior to filling the space heating circuit (and DHW circuit if it were the case) with water and checking water pressure and the total absence of any water leakage.
  • Do not connect or adjust any wiring or connections unless the main power switch is OFF.
  • When using more than one power source, check and ensure that all of them are turned OFF before operating the indoor unit.
  • Avoid wiring installation in contact with the refrigerant pipes, water pipes, edges of plates and electrical components inside the unit to prevent damage, which may cause electric shock or short circuit.

CAUTION

  • Use a dedicated power circuit for the indoor unit. Do not use a power circuit shared with the outdoor unit or any other appliance.
  • Make sure that all wiring and protection devices are properly selected, connected, identified and fixed to the correspond ing terminals of the unit, specially the protection (earth) and power wiring, taking into account the applicable national and local regulations. Establish proper earthing; Incomplete earthing may cause electrical shock.
  • Protect the indoor unit against the entry of small animals (like rodents) which could damage the drain pipe and any internal wire or any other electrical part, leading to electric shock or short-circuit.
  • Keep a distance between each wiring terminal and attach insulation tape or sleeve as shown in the figure.

Connection procedure

Access to the electrical box before performing the next steps:

  1. Using the appropriate cable, connect the power circuit to the appropriate terminals as shown on the wiring label and the illustration below. Connect the power supply cables to the terminal board (TB1) , and the earth conductor to the earth screw in the electrical box plate.HITACHI RWM Yutaki S Series Indoor Units - Earth termin

  2. Connect the transmission wires between outdoor and indoor unit to the terminals 1 and 2 on the terminal board 2 (TB2).

  3. Carry out the necessary electrical connections of the optional accessories using the terminal board 2 (TB2). Consult its label for a better understanding.
    NOTE
    Refer to the section “5.5 Optional indoor unit wiring (Accessories)”.

  4. Pass the electrical wiring from the TB1 and TB2 to the lateral holes of the electrical box. Then, fix the cables to the cord bands located at the right side. Finally, take the cables out through the bottom side of the unit.

6.3.6 Cover assembly

  1. Place the indoor unit service cover at the same level of the wall mounted unit by taking it from the bottom side (one person can perform this operation, during this operation it is possible to rest the cover on the electrical box).
  2. Place the holes on the right side of the indoor unit cover over the back plate hooks (x2 locations). When the right side is centred, repeat the operation on the left side. Put the holes on the left side of the indoor unit cover into the back plate frame hooks (x2 locations).
  3. Once the 4 hooks are placed into their corresponding cover holes, adjust the cover to the end of the hooks.HITACHI RWM Yutaki S Series Indoor Units - corresponding
  4. Fix the indoor unit service cover using the screw which had been previously removed during the unpacking procedure.

6.3.7 Test and check
Finally, test and check the following items:

  • Water leakage
  • Refrigerant leakage
  • Electrical connection

NOTE
Please refer to the chapters of “4.2.1 Refrigerant charge”, “4.4.6 Water filling” and “7 Commissioning” in this document and refer the Outdoor unit Installation and Operation manual for the specific details about refrigerant charge tasks.

DANGER
Do not connect the power supply to the indoor unit prior to filling the space heating circuit (and DHW circuit if it were the case) with water and checking water pressure and the total absence of any water leakage.

COMMISSIONING

7.1 BEFORE OPERATION

CAUTION

  • Supply electrical power to the system for approximately 12 hours before start-up after a long shut-off. Do not start the system immediately after power supply, it may cause compressor failure because the compressor is not well-heated.
  • When the system is started after a shut-off longer than approximately 3 months, it is recommended that the system be checked by your service contractor.
  • Turn OFF the main switch when the system is to be stopped for a long period of time: as the oil heater is always energized even when the compressor is not working, there will be electricity consumption unless the main switch is turned OFF.

7.2 PRELIMINARY CHECK
When installation is complete, perform commissioning according to the following procedure, and hand over the system to the customer. Perform the commissioning of the units methodically, and check that the electrical wiring and the piping are correctly connected.
Indoor and outdoor units must be configured by the installer to get the perfect setting and the unit working.
NOTE
For the commissioning of the outdoor unit please refer to the outdoor unit installation and operation manual.

7.2.1 Checking the unit

  • Check external appearance of the unit to look for any damage due to transportation or installation.
  • Check that all the covers are totally closed.
  • Check that the recommended service space is respected (see “3.1 Service space” and the outdoor unit Installation and operation manual).
  • Check that the unit has been correctly installed onto the wall.

7.2.2 Electrical checking
CAUTION
Do not operate the system until all the check points have been cleared:

  • Check to ensure that the electrical resistance is more than 1 MΩ, by measuring the resistance between ground and electrical parts terminal. If not, do not operate the system until the electrical leakage is found and repaired. Do not impress the voltage on the terminals for transmission and sensors.
  • Check to ensure that the switch on the main power source has been ON for more than 12 hours, in order to give the oil heater time to warm the compressor.
  • In three-phase unit check phase sequence connection on terminal board.
  • Check the power supply voltage (±10% of the rated voltage).
  • Check that field-supplied electrical components (main switches, breakers, wires, conduit connectors and wire terminals) have been properly selected according to the electrical specifications given in this document, and check that the components comply with national and local standards.
  • Do not touch any electrical components for more than three minutes after turning OFF the main switch.
  • Check the dip switch settings of the indoor unit and the outdoor unit are connected as shown in the corresponding chapter.
  • Check to ensure the electrical wiring of the indoor unit and the outdoor unit are connected as shown in the chapter.
  • Check to ensure the external wiring is correctly fixed. To avoid problems with vibrations, noises and cut out wires with the plates.

7.2.3 Hydraulic circuit checking (space heating and DHW)

  • Check that the circuit has been properly flushed and filled with water and that the installation has been drained: the pressure of the heating circuit must be 1.8 bar.
  • Check for any leakage in water cycle. Pay special attention to the water piping connections.
  • Make sure the system’s internal water volume is correct.
  • Check that the hydraulic circuit’s valves are fully open.
  • Check to see that electrical heater is completely filled with water by operating pressure of safety valve.
  • Check to see that additional water pumps (WP2 or/and WP3) are correctly connected to terminal board.

CAUTION

  • Operating the system with closed valves will damage the unit.
  • Check to see that air purge valve is open and that the hydrau lic circuit is air purged. The installer is responsible of com pletely air purging the installation.
  • Check that the water pump of the space heating circuit works within the pump operating range and that the water flow is over the pump’s minimum. If the water flow is under 12 litres/minute for 4.0-10.0 HP (6 litres/minute for 2.0/2.5/3.0HP unit) (with flow switch tolerance), alarm will be displayed on the unit.
  • Remember that water connection must be accordance with local regulations.
  • Water quality must comply with EU directive 98/83 EC.
  • Electrical heater operation when not completely filled with water will damage the heater.

7.2.4 Checking the refrigerant circuit

  • Check to ensure that the stop valves on the gas and liquid lines are fully open.
  • Check that the size of the piping and the refrigerant charge comply with the applicable recommendations.
  • Check the inside of the unit for refrigerant leakage. If there is a refrigerant leak, call your dealer.
  • Check outdoor unit commissioning procedure manual.

7.3 COMMISSIONING PROCEDURE
This procedure is valid regardless of what options are on the module.

  • When installation is complete and all necessary settings (Dip-switches in PCBs and user controller configuration) have been carried out, close the electrical box and place the cabinet as shown in the manual.
  • Make the start-up wizard configuration in the user controller.
  • Make a test run as shown in item “7.4 Test run / air purge”.
  • After test run is completed, start the entire unit or the selected circuit by pressing the OK button.

Initial start-up at low outdoor ambient temperatures

During commissioning and when water temperature is very low, it is important for the water to be heated gradually.
Additional optional function can be used for starting at low water temperature conditions: Screed drying function:
– The screed function is used exclusively for the process of drying a newly applied screed to the floor heating system.
The process is based on EN-1264 par 4.
– When user activates screed function, the water set point follows a predetermined schedule:

  1. Water set point is kept constant at 25ºC for 3 days.
  2. Water set-point is set to the maximum Heating supply temperature (but always limited to ≤ 55ºC) for 4 days.

CAUTION

  • Heating at lower water temperatures (approximately 10ºC to 15ºC) and lower outdoor ambient temperatures (<10ºC) can be damaging to the heat pump when defrosting.
  • As a result, Heating up to 15ºC when outdoor temperature is lower than 10ºC is performed by the Electrical Heater.

NOTE
In case of Heater Forced OFF (by optional dip switch setting) these condition is not performed and heating is performed by Heat Pump. Hitachi is not responsible for its operation.

CAUTION
It is recommended start the unit (first power ON) with heater forced OFF and compressor forced OFF (See “5.6 Setting of DIP switches and RSW switches”). In order to circulate water by water pump and remove possible air into the heater (Check heater completely filled).

7.4 TEST RUN / AIR PURGE
Test run is a working mode used when commissioning the installation. Some settings are made to let the installer an easy job. Air purge function drives the pump in a way for evacuating air bubbles in the installation.

HITACHI RWM Yutaki S Series Indoor Units - drives

This menu shows the following test to be launched:

  • Unit Test Run
  • Air Purge
  • Screed Drying
  • Pump down procedure

After “Test Run”, “Air Purge” or “Pump down procedure” option is selected, the YUTAKI user controller asks for the duration of the test.

HITACHI RWM Yutaki S Series Indoor Units - Unit Test
Run

In case of test run, user can also select the mode of the test (cooling or heating).
When user confirms the test run or the air purge, the YUTAKI user controller sends the order to the indoor.
During the execution of this test, the following screen is shown:

HITACHI RWM Yutaki S Series Indoor Units - confirms

  • When the test starts, the user controller will exit from the installer mode.
  • User can cancel the test run regardless of the time left for test finishing.
  • The Test Run icon is shown in the notifications zone, but the notification of this test run is taken from H-LINK.

When test run has finished, an information message is displayed in the screen, and pressing accept, the user returns to the global view.

NOTE

  • When commissioning and installing the unit, it is very important to use the “Air purge” function to remove all the air in the water circuit. When the air purge function is running, the water pump starts the automatic air venting routine which consists of regulating the speed and open/ close configured 3-way valve to help to evacuate air from the system.
  • For Outdoor test run, refer to Outdoor Unit Installation Manual.
  • If there is a Heater or a Boiler installed, disable the operation before running the test run.

UNIT CONTROLLER

8.1 DEFINITION OF THE SWITCHES

HITACHI RWM Yutaki S Series Indoor Units - SWITCHES

  1. Liquid Crystal Display
    Screen where controller software is displayed.

  2. OK button
    To select the variables to be edited and to confirm the selected values.

  3. Arrows key
    It helps the user to move through the menus and views.

  4. Run/Stop button
    It works for all zones if none of the zones is selected or only for one zone when that zone is selected.

  5. Return button
    To return to the previous screen.

8.2 MAIN VIEW

HITACHI RWM Yutaki S Series Indoor Units - MAIN VIEW

Main view of the device is composed by a bottom tab widget to move around the different views:

  • Home
  • Mode
  • Room 1 (if space is small it shows R1)
  • Room 2 (if space is small it shows R2)
  • Circuit 1 (if space is small it shows C1)
  • Circuit 2 (if space is small it shows C2)
  • Fan 1 (if space is small it shows F1)
  • Fan 2 (if space is smaill it shows F2)
  • DHW
  • SWP
  • Menu

8.2.1 Home view

HITACHI RWM Yutaki S Series Indoor Units - Home view

Home view shows on the middle the date and time.
On the left side it shows:

  • Inside temperature (home icon):
    – If LCD works as Room 1, it took it from the controller sensor or auxiliary sensor
    – If LCD works as Room 2, it took it from the controller sensor or auxiliary sensor
    – If LCD works as Room 1+2, it took it from the controller sensor or auxiliary sensor, or the average of the ones used per each zones.
    – If LCD works as main LCD or water control but not room, it will took them from the configured Rooms, if no one is configured, that temperature will not be displayed.

  • Outside temperature (thermometer icon).

  • Water pressure indicator.

8.2.2 Mode view

HITACHI RWM Yutaki S Series Indoor Units - Mode view

  • Mode view shows the selected mode.
  • In case of being a heating and cooling unit, it lets also to change the mode by using the top/bottom arrows, and it shows the mode spinner on the left side.
  • If it has been enabled the auto mode, it is also available here.

8.2.3 Room 1/2 view

HITACHI RWM Yutaki S Series Indoor Units - Room 1

  • Room thermostats view displays:
  • Ambient Temperature of the room. This temperature is got from controller or external sensor.
  • When editing it shows the setting temperature
  • On right side it has zone notifications for:
    – Next timer action
    – Eco and timer icons

8.2.4 Fan coils 1/2 view

HITACHI RWM Yutaki S Series Indoor Units - Fan coils

  • Room 1 or 2 could control Fan Coils. Once configured to control them on the menu, the bottom bar includes the option to manage those fan coils.
  • Fan speeds: Low, Medium, High and Auto.
  • Each fan has its independent on/off.

8.2.5 Circuit 1/2 view

HITACHI RWM Yutaki S Series Indoor Units - Circuit

Circuit 1 or 2 view displays:

  • Water setting feedback.
  • When editing it shows the setting temperature.
  • On right side it has zone notifications for:
    – Next timer action.
    – Eco, throughput, summer switch-off, forced off and timer icons.

8.2.6 DHW view

HITACHI RWM Yutaki S Series Indoor Units - DHW view

DHW view displays:

  • Water setting feedback.
  • When editing it shows the setting temperature.
  • On right side it has zone notifications for:
    – Next timer action.
    – Boost, throughput, operating in comfort and timer icons.
    – During boost, setting changed is the boost seeting.

8.2.7 SWP view

HITACHI RWM Yutaki S Series Indoor Units - SWP view

SWP view displays:

  • Water setting feedback.
  • When editing if shows the setting temperature.
  • On right side it has zone notifications for:
    – Next timer action.
    – Throughput and timer icons.

8.2.8 Next schedule indication

HITACHI RWM Yutaki S Series Indoor Units - schedule

The indication of next schedule shows by priority:

  • Date of returning of absent mode.
  • Next schedule action:
    – If no derogation has been made, shows next schedule action.
    – If derogation has been made it checks the configured override type:
    – If override type is Next action, it shows next schedule action.
    – If override type is Forever, does not show any information.
    – If override type is Specific time, it shows “Pending” text and the remaining minutes.

8.3 DESCRIPTION OF THE ICONS

Icon Name Explanation
Status for circuit 1, 2, DHW and swimming pool. OFF Circuit I or II

is in Demand-OFF
| Circuit I or II is on Thermo-OFF
| Circuit I or II is working between 0 < X ≤ 33% of the desired water outlet temperature
| Circuit I or II is working between 33 < X ≤ 66% of the desired water outlet temperature
| Circuit I or II is working between 66 < X ≤ 100% of the desired water outlet temperature
| Mode| | Heating
| Cooling
| Auto
| Setting temperatures| Value| Displays the setting temperature of the circuit 1, circuit 2, DHW and swimming pool
****| Circuit 1, Circuit 2, DHW or Swimming Pool are stopped by button or timer
| Alarm| Existing alarm. This icon appears with the alarm code
| Timer| Weekly timer
| Derogation| When there is a derogation from the configured timer
| Installer mode| Informs that user controller is logged on the installer mode which has special privileges
| Menu lock| It appears when menu is blocked from a central control. When indoor communication is lost, this icon disappears
| Holiday| When some of the zones are set as holiday, it has it’s own holiday icon on their icons zone.
The holiday icon is also shown on the home screen.
| Ambient temperature| The ambient temperature of Circuit 1 or 2 is indicated at the right side of this button
| Outdoor temperature| The outdoor temperature is indicated at the right side of this button
| Water pressure| The water pressure is indicated at the right side of this button
| Pump| This icon informs about pump operation.
There are three available pumps on the system. Each one is numbered, and its corresponding number is displayed below to the pump icon when it is operating
| Heater step| Indicates which of the 3 possible heater steps is applied on space heating
---|---|---
| DHW Heater| Informs about DHW Heater operation. (If it is enabled)
| Solar| Combination with solar energy
| Compressor| | Compressor enabled
| | Compressors enabled.
1: R410A/R32
2: R-134a (Not applicable)
| Boiler| Auxiliary boiler is working
| Tariff| Tariff signal informs about some cost conditions of the consumption of the system
| Defrost| Defrost function is active
| Central| | Central mode icon is shown after some central order has been received and for the next 60 seconds.
| Central error
| Forced OFF| When forced off Input is configured and its signal is received, all the configured items (C1, C2, DHW, and/or SWP) are shown in OFF, with this small icon below
| Auto ON/OFF| When daily average is over auto summer switch-off temperature, circuits 1 and 2 are forced to OFF (Only if Auto ON/OFF enabled)
| Test Run| Informs about the activation of the “Test Run” function
| Anti-Legionella| Activation of the Anti-Legionella operation
| DHW boost| It activates the DHW heater for an immediate DHW operation
| ECO mode| –| No icon means Comfort mode
| ECO/Comfort mode for circuits 1 and 2
| Night Shift| Informs about night shift operation
| CASCADE CONTROLLER| Informs about the activation of the “CASCADE” mode.
| CASCADE CONTROLLER in alarm state
| Fan stopped by Demand OFF| Informs about the stopagge of fan 1 or 2 by Demand OFF

Cooling & Heating
Johnson Controls-Hitachi Air Conditioning Spain, S.A.U.
Ronda Shimizu, 1 – Políg. Ind. Can Torrella
08233 Vacarisses (Barcelona) Spain
© Copyright 2021 Johnson Controls-Hitachi Air Conditioning Spain, S.A.U. – All rights reserved.
PMML0574 rev.2 – 02/2023

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