MR COOL Hyper Heat Single Zone 24K 60K Ducted Air Handler Instruction Manual

MR COOL Hyper Heat Single Zone 24K 60K Ducted Air Handler

Product Information

The product is the Hyper-Heat Single-Zone 24K-60K Ducted Air Handler, designed for installation in HVAC systems. It is capable of providing both heating and cooling functions.

This product manual contains important information regarding the installation, operation, and maintenance of the air handler. It is essential to read and understand this manual before proceeding with the installation.

Please note that the information and instructions provided in this manual are subject to change without notice. To ensure you have the most up-to-date version of the manual, visit www.mrcool.com/documentation. The version date of this manual is 04/24/2023.

Product Usage Instructions

Safety Precautions:
Read and follow all warnings and cautions mentioned in the manual to ensure safe installation and operation.

Indoor Unit Overview & Features:
Refer to section 1 of the manual for an overview of the indoor unit and its features.

Indoor Unit Installation:
Follow the instructions provided in section 2 of the manual for the proper installation of the indoor unit.

Installation of Air Handler Heat Kit (Optional):
If applicable, refer to section 3 of the manual for instructions on installing the optional air handler heat kit.

Outdoor Unit Installation:
For outdoor unit installation, follow the instructions provided in section 4 of the manual. The manual also includes outdoor unit dimensions for reference.

Drain Pipe Installation:
Refer to section 5 of the manual for instructions on installing the drain pipe for the indoor unit.

Refrigerant Piping Connections:
Section 6 of the manual provides instructions on making refrigerant piping connections.

Electrical Connections:
Follow the guidelines in section 7 of the manual for proper electrical connections.

Air Evacuation & Adding Refrigerant:
Before proceeding with air evacuation and refrigerant addition, read the preparations and precautions mentioned in section 8 of the manual. The manual also includes specific instructions for air evacuation and a note on adding refrigerant.

Care & Maintenance

Refer to section 9 of the manual for information on care and maintenance procedures to keep the air handler in optimal condition.

Electrical & Gas Leak Checks:
Section 10 of the manual provides instructions for conducting electrical safety checks and gas leak checks.

Test Run:
Prior to the test run, follow the instructions mentioned in section 11 of the manual. The manual includes test run instructions and a drainage system test procedure.

Troubleshooting:
If any issues arise, refer to section 12 of the manual for common troubleshooting tips.

EU Disposal Guidelines:
For information on EU disposal guidelines, refer to section 13 of the manual.

IMPORTANT INSTALLATION INFORMATION!

It is important to note that handling materials containing refrigerants under pressure can be dangerous. If you are not comfortable with the installation process, it is recommended to seek the assistance of a qualified HVAC professional.

Please read this manual carefully before installation and keep it for future reference.
Installation & Owner’s Manual
Hyper-Heat Single-Zone 24K-60K Ducted Air Handler
Due to updates and constantly improving performance, the information and instructions within this manual are subject to change without notice. Please visit www.mrcool.com/documentation to ensure you have the latest version of this manual. Version Date: 04/24/2023

IMPORTANT INSTALLATION INFORMATION!
Refrigerant Line Set Connection Options, Requirements, and Stipulations 24K/36K/48K/60K Capacity Units are designed to be installed using either a traditional flare nut configuration of refrigerant piping or the optional MRCOOL® No-Vac® Quick Connect® Pre-Charged Line Set. If the optional No-Vac® Quick Connect® Pre-Charged Line Set is used, you DO NOT have to retain the services of a professional HVAC installer. If the traditional flare nut configuration is selected, you ARE REQUIRED to retain the services of a professional HVAC installer. Stub pipes and copper nuts are included with these capacity units to complete this type of installation. If any other form of installation is attempted, or these stipulations are not followed, the WARRANTY WILL BE VOIDED.
DISCLAIMER: You are assuming risk by handling materials containing refrigerants under pressure, that if not handled properly, can cause bodily injury. If you do not feel comfortable conducting this installation process,we recommend you retain the services of a qualified HVAC professional.
Electrical work must be completed by a qualified electrical technician.

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Safety Precautions

!

Read Before Using
Incorrect usage may cause serious damage or injury. The symbols below are used throughout this manual to indicate instructions that should be followed closely or actions that should be avoided to prevent death, injury, and/or property damage.

This symbol indicates ignoring instructions may cause death or serious injury.
WARNING

CAUTION

This symbol indicates ignoring instructions may cause bodily injury, damage to the unit, or other surrounding property.

This symbol indicates that you should NEVER perform the indicated action.

WARNING FOR PRODUCT INSTALLATION
DISCLAIMER: You are assuming risk by handling materials containing refrigerants under pressure, that if not handled properly can cause bodily injury. If you do not feel comfortable performing this installation process, we recommend you retain the services of a qualified HVAC professional.
ELECTRICAL WORK MUST BE COMPLETED BY A QUALIFIED ELECTRICAL TECHNICIAN
DO NOT install the unit in a location that may be exposed to combustible gas leaks. If combustible gas accumulates around the unit, it could cause fire.
DO NOT turn on the power until the installation and all work has been completed.
DO NOT install a unit equipped with an auxiliary electric heater within 3 ft (1 m) of any combustible materials. 1. Installation must be performed according to the installation instructions. Improper installation could cause water leakage, electrical shock, fire, and could void the warranty. (In North America, all wiring/electrical work must be performed in accordance with the requirements of NEC and CEC by authorized personnel only.) 2. Contact an authorized service technician for repair or maintenance of this unit. This appliance should be installed in accordance with national wiring regulations. 3. Only use the included accessories, parts, and specified parts for installation. Using non-standard parts can cause water leakage, electrical shock, fire, and/or failure of the unit. 4. Install the unit in a firm location that can support the unit’s weight. If the location cannot support the unit’s weight, or the installation is not done properly, the unit may drop and cause serious injury and damage. 5. Install the drainage piping according to the instructions in this manual. Improper drainage could cause water damage to your home and/or property. 6. When moving or relocating the air conditioner, consult experienced service technicians for disconnection and re- installation of the unit. 7. For detailed information of how to install the indoor and outdoor units to their respective supports, please refer to the indoor unit installation and outdoor unit installation sections of this manual. 8. Excessive Weight Hazard: Use two or more people when moving and installing the unit. Failure to do this could result in personal injury.

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Safety Precautions
WARNING FOR PRODUCT USE
DO NOT insert fingers, rods, or other objects into the air inlet or outlet. This could cause injury,
since the fan may be rotating at high speeds. DO NOT use flammable sprays such as hair spray, lacquer or paint near the unit, as this could cause fire and/or an explosion. DO NOT operate the unit in places near or around combustible gases. Emitted gas may collect around the unit and cause an explosion. DO NOT allow children to play with the appliance. Children must be supervised around the unit at all times. DO NOT operate the unit in a room where it could be exposed to excessive amounts of water, such as a bathroom or laundry room. Exposure to excessive water amounts can cause the electrical components to short circuit. DO NOT expose your body directly to focused cool airflow from the unit for a prolonged period of time.
1. If the unit operates abnormally (emits strange noises or a burning a smell), immediately turn off the unit and disconnect the power in order to avoid electric shock, fire, and/or injury. Call your local dealer, or MRCOOL® tech support at 270-366-0457, for further assistance.
2. If the air conditioner is used together with burners or other heating devices, thoroughly ventilate the room in order to avoid an oxygen deficiency.
3. In certain functional environments (such as kitchens and server rooms etc.), the use of specially designed air-conditioning units is highly recommended.
4. This appliance can be used by children (8 years and older) and persons with reduced physical, sensory
or mental capabilities, or lack of experience and knowledge if they have been given instruction c oncerning the use of the appliance and understand the hazards involved. 5. This unit is not designed for non-ducted (freeblow) applications. Electric heat kits and the blower are easily accessible without ducting. Operating this unit without ducting would create a major safety hazard and the potential for electric shock and/or personal injury.
ELECTRICAL WARNINGS
ELECTRICAL WORK MUST BE COMPLETED BY A QUALIFIED ELECTRICAL TECHNICIAN
DO NOT share the power supply with other appliances. An improper or insufficient power supply could cause fire and/or electrical shock. 1. The product must be properly grounded during installation or electrical shock could occur.
2. Appropriate wiring standards, regulations, and the installation manual must be followed for all electrical work.
3. If connecting power to fixed wiring, the following must be incorporated within it, in accordance with the wiring rules; an all-pole disconnection device (which has at least 3 mm of clearances in all poles), and have a leakage current that may exceed 10 mA, the residual current device (RCD) having a rated residual operating current not exceeding 30 mA, all must be present.
4. For all electrical work, fuse the specified cables. Connect cables tightly and clamp them securely to prevent external forces from damaging the terminal. Improper electrical connections could overheat, causing fire and/or electrical shock.
5. All electrical connections must be made according to the Electrical Connection Diagram located on the panels of the indoor and outdoor units.
6. All wiring must be properly arranged to ensure that the control board cover can close properly. If the control board cover is not properly closed, it can lead to corrosion and cause the connection points on the terminal to heat up, catch fire, or cause electrical shock.

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Safety Precautions

WARNING FOR CLEANING & MAINTENANCE
DO NOT clean the unit with excessive amounts of water. DO NOT clean unit with combustible cleaning agents, as these could cause deformation and/or fire. 1. Turn off the device and disconnect the power before cleaning. Failure to do this could result in electrical shock. 2. Children should not be allowed to play with the appliance or perform cleaning and user maintenance.

CAUTION
DO NOT allow the unit to operate for extended periods of time with the doors or windows open, or in very high humidity. DO NOT operate the unit with wet hands, as this could cause electric shock.
DO NOT use device for any other purpose than its intended use.
DO NOT climb onto or place objects on top of the outdoor unit. 1. Make sure that water condensation can drain smoothly and unhindered from the unit. 2. Turn off the unit and disconnect the power if the unit will not be used for an extended period of time. 3. As with any mechanical equipment, contact with sharp sheet metal edges can result in personal
injury. Ensure care is taken when handling the unit and any of its accessories by wearing gloves and protective clothing.

NOTE ON FLUORINATED GASES:
1. This unit contains fluorinated greenhouse gases. 2. For specific information on the type of gas and the amount, please refer to the relevant label on
the unit itself. 3. Service, maintenance, and repair of this unit must be performed by a certified technician. 4. Product un-installation and recycling must be performed by a certified technician.

NOTE ON STATIC PRESSURE

The allowed static pressure range of the air handler on site 0.00-0.80 in H20 (0-200 Pa). The data below represents the static pressures at the full required airflow used for AHRI testing.

Model

24-60K

Pressure 0.50 in H20 (125 Pa)

Units: Inch of Water Column (Pascals)
NOTE: The maximum functional total external static pressure cannot exceed 0.80 in WC (200 Pa). The airflow reduces significantly at pressures above and beyond 0.80 in WC (200 Pa). The system design should allow for the increased resistance of filters as they become dirty.

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Safety Precautions
Indoor Unit Overview & Features

Indoor Unit Overview

Air outlet

1

Air inlet

Operating Temperature Ranges

Room Temperature

COOL Mode
61°F – 90°F (16°C – 32°C)

HEAT Mode
32°F – 86°F (0°C – 30°C)

DRY Mode
50°F – 90°F (10°C – 32°C)

Outdoor Temperature

5°F – 122°F (-15°C – 50°C)

-22°F – 75°F (-30°C – 24°C)

32°F – 122°F (0°C – 50°C)

NOTE: The unit is designed to be operated in the temperatures in the above chart
for safe and effective operation. If the unit is operated outside of these temperatures, it could become less efficient and/or malfunction.

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Indoor Unit Overview & Features

Features Refrigerant Leak Detection System (some models)
In the event of a refrigerant leak, the LCD screen will display “EL0C” and the LED indicator light will flash.
NOTE
1. Requirements of wired controller: Control AXU function for live heating. 2. The default temperature of the unit during the first start up is 60.8°F (16°C) during cooling
mode and 86°F (30°C) during heating mode. When the unit stops running it is at the current room temperature.

Optimal Operation

To achieve optimal performance, please note the following:
DO NOT put any objects near the air inlets & outlets. Doing this would impair performance.

DO NOT set the unit to excessive or extreme temperature levels.

· While cooling, close curtains to avoid direct sunlight.

· Keep windows and doors closed, as this will keep cool or warm air in the room.

Doors and windows Closing the curtains

should be kept

while heating also

closed.

helps keep the heat in

· Limit energy usage by using scheduling functions. · Clean the air filter every two weeks. · Replace the air filter every 30 to 90 days
depending on thickness and the filter’s MERV rating (minimum efficiency reporting value).

· Adjust louvers properly and avoid direct airflow.

Additional Line Sets & Coupler Kit
If you find the default line set lengths are not sufficient for your application, additional line sets are available for purchase. You will also need a coupler kit (pictured below), which allows line sets to be connected together. The coupler kit is installed and checked for leaks by following the same steps described in this manual for connecting the line set to the indoor air handler (Refer to Section 6: Refrigerant Piping Connections for these steps).

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Accessories

The listing below shows the accessories and parts (these may vary depending on purchase & options). Use all of the installation parts and accessories to install the system. Improper installation may result in water leakage, electrical shock, fire, and/or equipment failure.

PART Owner’s & Installation
Manual
Remote Controller

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QUANTITY 1 1

Remote Controller User Manual

1

Batteries

2

Stub Pipes (2 packed with indoor unit,
2 packed outdoor unit)

4 3/8″ (1 with indoor / 1 with outdoor) 3/4″ (1 with indoor / 1 with outdoor)

Thermostat
Thermostat Manual
Fastening Belts Drain Joint
(Packed with outdoor unit)
Seal
(Packed with outdoor unit)
Foam Insulator
Copper Nut 3/8″ (1) 3/4″ (1)
No-Vac® Quick Connect® Line Set
Pat. https://mrcool.com/mrcool-patents/

1
1 2 1 1 4
2

Not Included

Optional Parts

Note: Illustrations are for explanatory purposes only – The actual shape and size may vary.

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Indoor Unit Installation

2

INDOOR UNIT INSTALLATION
Indoor Unit Parts
Coil Compartment (Access panel Removed)
UUppflow drain pan
Horizontal drain pan
Fig. 2.1 Safety Precautions
WARNING
DO NOT install the indoor unit in a bathroom, laundry room, or any location where it could be exposed to excessive amounts of moisture. This could cause
. the wiring of the unit to short or corrode. Securely install the indoor unit on a structure that can sustain the weight of the unit. If the structure is too weak, the unit could fall and cause personal injury,
. unit or property damage, and/or death. Keep flammable materials and vapors (such as gasoline) away from the air handler. Also, ensure that any heating elements are at least 18 in (46 cm) above the floor if the air handler is being installed in a garage. Failure to follow these instructions could result in death, fire, and/or explosion.
. CAUTION Install the indoor and outdoor units, cables, and wires at least 3.2 ft (1 m) away from televisions or radios to prevent static or image distortion. Depending on the appliances, a 3.2 ft (1 m) distance may
. not be sufficient. If the indoor unit is installed on metal, it must be electrically grounded.

Indoor Unit Installation Instructions
The indoor unit should be installed in a location that meets the following requirements:
Enough room for the installation and maintenance to be performed. Enough room for the refrigerant piping and drain pipe. The ceiling is horizontal and its structure can sustain the weight of the indoor unit. The air inlet and outlet are not impeded.
Room for properly sized return and supply ducts must be maintained. There is no direct radiation from heaters.
CAUTION
DO NOT install the indoor unit in any of the following locations:
Areas where oil drilling or fracking is being performed. Coastal areas with high salt content in the air. Areas with caustic gases in the air, such as near laundry vents. Areas where power fluctuations can occur, such as near a factory. Enclosed spaces, such as cabinets. Areas with strong electromagnetic waves. Areas where flammable materials or gas are stored. Rooms with high humidity, such as bathrooms or laundry rooms.
IMPORTANT · Be sure to apply sealant around any places
where wires, refrigerant piping, and condensate piping enter the air handler cabinet.
· Use duct tape and/or sealing compound to seal any space around the holes where condensate piping exits the cabinet. Warm air must not be allowed to enter through any gaps or holes in the cabinet.

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E E

Indoor Unit Installation

Indoor Unit Dimensions and Clearance Requirements

WARNING
· There must be an airtight seal between the bottom of the air handler and the return air plenum. In order to achieve this, use fiberglass sealing strips, foil duct tape, caulking, or an equivalent sealing method to ensure a tight seal.
· Return air must not be drawn from a room where the air handler or any gas- fueled appliance (ex: water heater), or carbon monoxide-producing device (ex: wood fireplace) is installed.
Indoor Unit Clearance Requirements
The distance between the mounted indoor unit should meet the specifications illustrated in the following diagram.
Horizontal Installations Plenum Clearances

C B

Indoor Unit Dimensions

A

D

Flexible Duct Collar

ou5t9leitns(id1e.5pmip)e

Vertical Installations

– Or –

MINIMUM CLEARANCE of 1 in (25.4 mm) on all sides

D

Unit: inch (millimeter)

Dimensions

Model Capacity (Btu/h)

24K

36K~48K

60K

Length of A

45 in (1143 mm)

49 in (1245 mm)

53 in (1346 mm)

Length of B

21 in (533 mm)

21 in (533 mm)

21 in (533 mm)

Length of C

17.5 in (445 mm)

21 in (533 mm)

24.5 in (622 mm)

Length of D

15.75 in (400 mm)

19.3 in (490 mm)

22.85 in (580 mm)

Length of E

10.25 in (260 mm)

10.25 in (260 mm)

10.25 in (260 mm)

Filter Dimensions

Mounting instructions: When installed vertically (upflow or downflow), the lower end of the air outlet needs to be connected to the L-shaped metal air duct and fastened by screws.

Model Capacity
(Btu/h) 24K
36K-48K
60K

Unit: inch (millimeter)

Width

Depth Thickness

16 in

20 in

1 in

(406.4 mm) (508 mm) (25.4 mm)

20 in

20 in

1 in

(508 mm) (508 mm) (25.4 mm)

23 in

20 in

1 in

(584.2 mm) (508 mm) (25.4 mm)

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Indoor Unit Installation

Indoor Unit Dimensions and Clearance Requirements (continued)

Vertical installations

Horizontal installations

Minimum clearance required between air handler & wall
24 in (610 mm)

24 in (610 mm)

Note on Ductwork & Connections
Air supply and return can be handled in one of several ways depending on which is best suited for the type of installation. Please see the dimensions on the previous page to determine duct inlet and outlet connection sizes to match the air handler. The vast majority of problems encountered with combination cooling systems can be linked to improperly designed or installed ductwork. For this reason, it is highly important that the duct system be properly designed and installed.
The use of flexible duct collars will minimize the transmission of vibration and noise into the conditioned space. In an installation where the return air duct is short, or where sound is likely to be a problem, a sound absorbing liner should be used inside the duct.
Insulation of the ductwork is a requirement anywhere it runs through an uncooled space during the cooling season. The use of a vapor barrier is recommended to prevent absorption of moisture from the surrounding air into the insulation. The supply air duct should utilize a properly sized transition in order to match the unit opening. All ducts should be suspended using flexible hangers and never fastened directly to the structure. This unit is not designed for non-ducted (free-blow) applications. Ductwork should be fabricated and installed in accordance with local and/or national codes.

Installation Mounting Positions

The unit can be installed in a vertical (downflow or upflow) or a horizontal (right or left) configuration.

Vertical up installations

Horizontal installations

Page 11

IMPORTANT
· A field-fabricated secondary drain pan (not included), with a drain pipe to the outside of the building is required in all installations over a finished living space or in any area that may be damaged by overflow from the main drain pan. NOTE: A secondary drain pan is required for horizontal installations.
· This unit is not designed for non-ducted (free-blow) applications. Electric heat kit elements and/or blower is easily accessible without ductwork and creates a safety hazard that could result in electric shock and/or personal injury.
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Indoor Unit Installation
Installation Mounting Positions (continued)

Horizontal Left

Vertical Upflow Vertical Downflow

Horizontal Right

Temperature Sensor Locations

The illustrations below represent the position of each temperature sensor of the evaporator coils. Location

dependent on model/capacity.

24K model

36K & 48K model
T2

60K model
T2

T2B

T2 T2B

T2B

T1

EEV

EEV

EEV

T2A

T1

T2A T1

T2A

NOTE: T2A & T2B sensors are only available on some units.
Installation Overview For Horizontal Left or Vertical Upflow
The steps below represent an overview of completing the installation of a horizontal left or vertical upflow indoor unit once it has been securely mounted in place. Please refer to the sections further in this manual for more detailed information of each step.
1.) Open the upper cover.
2.) Open the cover of the electronic control box.
3.) Connect the wiring according to the appropriate wiring diagram (connect wiring to outdoor condenser first). Please refer to the Electrical Connections section.
4.) Replace cover of electronic control box & reinstall upper cover.
5.) Connect the refrigerant piping.
6.) Install the drainage pipes.
NOTE ON HORIZONTAL RIGHT & VERTICAL DOWNFLOW INSTALLATIONS If you’re planning to install the indoor unit in a horizontal right or vertical downflow configuration,additional steps are required for the unit to be installed in these positions. The evaporator and drain pan will need to be removed from the cabinet and rotated 180° then reinstalled. For more detailed instructions on how to complete these steps, please refer to the next page.

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Indoor Unit Installation

Horizontal Right & Vertical Downflow Conversion & Installation Overview
In order to install the air handler in a horizontal right or vertical downflow position the following steps must be completed. If these steps are not followed, the unit may not operate correctly and it could cause damage to the unit, personal property, and/or cause personal injury.

1. Remove the filter door, then remove the filter.

2. Remove the upper cover assembly. 3. Remove evaporator cover plate.

4. Remove T1, T2, T2A, T2B sensor plug, and EEV valve wiring.
Disassemble T1, T2, T2A, T2B temperature sensor and EEV.

5. Remove T1, T2, T2A, T2B temperature sensor, & EEV wire ties.

T2: Evaporator central sensor plug T2A: Evaporator input sensor plug T2B: Evaporator output sensor plug T1: Room temperature sensor EEV: Electronic expansion valve

6. Remove the evaporator and drain pan. Then, rotate them 180°
2

T2 T2A & T2B T1 EEV

1
NOTE The T2A and T2B sensors are only available on some units.

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Indoor Unit Installation

7. Adjust the position of the two mounting brackets .

8. Reinstall the evaporator and drain pan.

9. Reinstall T1, T2, T2A, T2B sensor plug, EEV, and tie up the temperature sensor wires.

10. Evaporator assembled in place.

NOTE
The wiring harness needs to be routed so it passes through the groove of the water receiving tray and is then placed on the hook of the water receiving tray as shown below. Follow the directions in Fig. 2.2 for step-by-step instructions of how to complete this step.

Cut the foam gasket.
Remove knockouts as shown.
Hook the wire into the buckle and feed it down through the wire slot.
Paste the foam gasket back into place.
Fig. 2.2

Use cable ties to secure the room
temperature sensor as shown.

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Indoor Unit Installation

11. Reinstall the evaporator cover plate.

12. Open the cover of the electronic 16. Reinstall the filter and filter

control box.

plate.

13. Connect the wiring according to the

appropriate wiring diagram (connect

wiring to outdoor condenser first).

Please refer to the Electrical

Connections section.

14. Close the cover of the electronic

control box.

15. Reinstall the upper cover assembly.

17. Connect refrigerant piping. 18. Install drainage pipes.

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Installation of AiOrpHeraantidngleInrsHtreuacttioKnist (Optional, not included)

3

Accessories Included with Heat Kit
PART
Owner’s and Installation Manual
Foam Gasket Screws Silicone Breaker Cover Electric Auxiliary Heating Wiring Diagram Air Switch/Circuit Breaker Label

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1 7 1 1 1

NOTE
Installation of heat kit must be performed by an authorized dealer or specialist. Please make sure to wear protective gear and follow all necessary rules and regulations when installing the heat kit.
The heat kits available for the central ducted unit are to be only installed internally within the unit in accordance with the installation instructions on the following pages. The sizes available are 5kw, 8kw, 10kw, 15kw, & 20kw. Only certain capacities of the heat kits are compatible with each capacity of the air handler. NOTE: If the incorrect capacity heat kit is used it could cause damage to your unit, property, and/or personal injury. Please use the table below to determine which heat kit capacities are compatible with the capacity of unit being installed and will best suit the needs of the application.

AHU Capacity (BTU/hr)
24K 36K 48K 60K

MRCOOL Heat Kit Compatibility Chart Heat Kit Capacity (Kilowatts)

CENTRALHK05 CENTRALHK08 CENTRALHK10 CENTRALHK15 CENTRALHK20

(5kW)

(8kW)

(10kW)

(15kW)

(20kW)

Y

Y

Y

Y

/

Y

Y

Y

Y

Y

/

Y

Y

Y

Y

/

/

Y

Y

Y

mmrcrcooool.lc.coomm

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Installation of Air Handler Heat Kit

Installation Requirements
Before performing installation of the heat kit, ensure that the heat kit and accessories have not been damaged in shipping. If any damage is found, please contact the MRCOOL® tech department or your local dealer immediately. Also, confirm that all of the included accessories required for the installation are present and accounted for.
NOTE: Please check the table on the previous page and ensure the capacity of the heat kit you have is compatible with the capacity of the air handler being installed.

Heat Kit Installation Instructions
1. Remove the upper cover and use tools to completely remove the knockout panels from the cover.

2. Remove the terminal block and power cord. Then, loosen the screws that are securing
the access panel and remove it. Access
Panel

Knockout panel to
be removed

3. Now, slide the electric heat kit into the access hole of

4. Secure the heat kit in place with screws.

the air handler. There are four prongs on the front of the heat kit, ensure these line up and lock into the

ssccrerwesws

corresponding four support holes on the back of the cabinet.

slide heat kit into air handler
access hole

4 prongs of heat kit

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Installation of Air Handler Heat Kit

5. CIonmpsletteawilrlinag otfihoeant kitDaccioardgingrtao tmhe

Once the electric heat kit wiring is connected and

wiring nameplate.

the unit installation is completed, please perform

6. Reinstall the upper cover of the air handler.

the following checks before powering on the unit

7. Install silicone breaker cover to the upper cover.

and heat kit.

· Check all wiring and ensure that all wiring is

securely and properly connected.

· Ensure the screws used to mount the heat kit are securely fastened.

· Ensure the size of the power wire meets the power supply requirements and NEC/local codes using the information below and contained within the electrical connections section further in this manual.

Heat Kit Number Number Number of Number of Capacity of circuit of power cord power cord (kilowatts) breakers relays groups grounding
screws

5kW

1

1

2

2

8kW

1

2

2

2

10kW

1

2

2

2

15kW

2

3

3

3

20kW

2

4

3

3

NOTE · The heat kit wiring diagram is with the included accessories. · Please attach or paste the wiring diagram to the inside cover once the installation is complete for future reference. · After installing the heat kit, affix the air switch label near the upper cover air switch.
Heat Kit Electrical Data 208/230V

Circuit 1

Circuit 2

Heat Kit Internal Heat

Capacity Circuit

Kit

(kilowatt) Protection Amps

MCA (1)

MOCP (2)

Heat Kit Amps

MCA (1)

MOCP (2)

5kW

Ckt Bkr 18.0/20.0 23.0/27.0 25.0/30.0

8kW

Ckt Bkr 28.8/32.0 37.0/42.0 40.0/45.0

10kW

Ckt Bkr 36.1/40.0 46.0/53.0 50.0/60.0

15kW

Ckt Bkr 18.0/20.0 23.0/27.0 25.0/30.0 36.1/40 46.0/53.0 50.0/60.0

20kW

Ckt Bkr 36.1/40.0 46.0/53.0 50.0/60.0 36.1/40 46.0/53.0 50.0/60.0

1. Minimum Circuit Ampacity (Heater Amps + Motor Amps) x 1.25 2. Maximum Overcurrent Protection = 2.25 x (Motor Amps + Heater Amps)

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Installation of Air Handler Heat Kit
Installation Diagram
Heat Kit Wiring Diagrams
5KW HEAT KIT
:thermal cut-out :thermal link, self-resetting

Aux-Heat control signal

TO INDOOR UNIT MAINBOARD cn12

RED BLACK

24V

0 RELAY1
1

68 24

RED BLACK

TCO1 TL1

HTR1

TO INDOOR UNIT MAINBOARD cn11
3

BLACK RED

RED BLACK YELLOW

(green)

1(L1) 2(L2) 3(S)

Y/G

Y/G

CB1

CB L1

CB L2

L1 L2

POWER A

POWER B

NOTE 1:
This symbol indicates the element is optional, The wiring type of the actual unit shall prevail.

NOTE 2: Please attach the nameplate to the cover of the electric control box. All the round holes located on the plate represent numbers. Please refer to the Installation Manual for details.

NOTE 3: TO BE WIRED IN ACCORDANCE

WITH NEC AND LOCAL CODES.

The wiring mode of power supply A shall

NOTE 4: POWER A,B,C,D ARE

be based on the type of original wiring

DIFFERENT POWERS.

terminal of the Central Ducted Unit; for

Round hole number Relay number Round hole number Circuit breaker number type A, S position must be connected to the

outdoor S; for type B, S position shall not

RELAY 1

CB1

be connected.

1(L1) 2(L2) 3(S) Y/G

Y/G
L1 L2

TYPE A

TYPE B

8KW/10KW HEAT KIT
:thermal cut-out :thermal link, self-resetting

0
RELAY1 1

68 24

BLACK RED

TL1

TCO1

HTR1

Aux-Heat

RED

BLACK

control signal

RED

0

TO INDOOR UNIT

MAINBOARD CN12

BLACK

RELAY2

1

24V

68 24

BLACK RED

TL2

TCO2

HTR2

RED

BLACK

TO INDOOR UNIT

RED

MAINBOARD

3

CN11

BLACK CB1

RED BLACK YELLOW

(green)

CB L1

CB L2

NOTE 1: This symbol indicates the

1(L1) 2(L2) 3(S)
Y/G

element is optional, The wiring

type of the actual unit shall prevail. POWER A

Y/G

L1 L2

POWER B

NOTE 2: Please attach the nameplate to the cover of the electric control box. All the round holes located on the plate represent numbers. Please refer to the Installation Manual for details.

NOTE 3: TO BE WIRED IN ACCORDANCE

WITH NEC AND LOCAL CODES.

The wiring mode of power supply A shall

NOTE 4: POWER A,B,C,D ARE

be based on the type of original wiring

DIFFERENT POWERS.

terminal of the Central Ducted Unit; for type

Round hole number Relay number

Round hole number Circuit breaker number

A, S position must be connected to the outdoor S; for type B, S position shall not

RELAY 1

CB1

be connected.

RELAY 2

1(L1) 2(L2) 3(S) Y/G

Y/G
L1 L2

TYPE A

TYPE B

NOTE

The optional heat kits use a power supply that is independent of the power supply of the air

handler & blower. Please be aware of this when wiring the heat kit.

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mrcool.com

Installation of Air Handler Heat Kit

15KW HEAT KIT
:thermal cut-out :thermal link, self-resetting

0 RELAY4
1

68 24

RED BLACK

TCO3 TL3

HTR3

BLACK

0 RELAY1
1

68 24

BLACK RED

TL1 TCO1

HTR1

Aux-Heat

RED BLACK BLACK

control signal

TO INDOOR UNIT MAINBOARD CN12

BLUE RED BLACK

NOTE 1:

24V

0 RELAY2
1

This symbol indicates the element is optional, The wiring type of the actual

TO INDOOR UNIT MAINBOARD CN11
3

unit shall prevail.

68 24

BLACK RED

TL2 TCO2

RED RED
CB2

CB L1

CB L2

HTR2
BLACK BLACK

RED BLACK

CB1

CB L1

CB L2

RED BLACK YELLOW

NOTE 2: Please attach the

(green)

nameplate to the cover of the 1(L1) 2(L2) 3(S)

electric control box. All the

Y/G

Y/G

L1 L2

Y/G

L1 L2

round holes located on the

plate represent numbers. Please POWER A

POWER B

POWER C

refer to the Installation Manual

for details.

NOTE 3: TO BE WIRED IN ACCORDANCE

WITH NEC AND LOCAL CODES.

NOTE 4: POWER A,B,C,D ARE DIFFERENT POWERS.

The wiring mode of power supply A shall be based on the type of original wiring terminal of the Central Ducted Unit; for type A, S

Round hole number Relay number Round hole number Circuit breaker number position must be connected to the outdoor

RELAY 1

CB1

S; for type B, S position shall not be connected.

RELAY 2 RELAY 4

CB2

1(L1) 2(L2) 3(S) Y/G

Y/G
L1 L2

TYPE A

TYPE B

20KW HEAT KIT
:thermal cut-out :thermal link, self-resetting

0

RED

TCO4

RELAY4 8 6

TL4

BLACK

1
RED

4

2

BLACK

0

RED

TCO3

8

6

TL3

RELAY3

BLACK

1

4

2

HTR4 HTR3

BLACK
BLACK RED

NOTE 1:

RED

This symbol indicates the element is optional, The wiring type of the actual
unit shall prevail.

0 RELAY1
1

68 24

BLACK RED

TL1 TCO1

HTR1

Aux-Heat

RED BLACK

control signal

BLUE

0

TO INDOOR UNIT

RED

MAINBOARD

BLACK

CN12

24V

1

BLACK RELAY2

68 24

BLACK RED

TL2 TCO2

HTR2

NOTE 2: Please attach

TO INDOOR UNIT

MAINBOARD CN11

3

RED

BLACK

RED

CB2

BLACK

CB1

RED BLACK YELLOW

thenameplate to the cover of the electric control box.

(green)

CB L1

CB L2

CB L1

CB L2

All the round holes located on the plate represent numbers. Please refer to the

1(L1) 2(L2) 3(S)
Y/G

Y/G

L1 L2

Y/G

L1 L2

Installation Manual for details.

POWER A

POWER B

POWER C

NOTE 3: TO BE WIRED IN ACCORDANCE WITH NEC AND LOCAL CODES.

NOTE 4: POWER A,B,C,D ARE

The wiring mode of power supply A shall be

DIFFERENT POWERS.

based on the type of original wiring terminal

Round hole number Relay number Round hole number Circuit breaker number of the Central Ducted Unit; for type A, S position must be connected to the outdoor S; for type B,

RELAY 1

CB1

S position shall not be connected.

RELAY 2 RELAY 3

CB2
1(L1) 2(L2) 3(S) Y/G

Y/G
L1 L2

RELAY 4

TYPE A

TYPE B

NOTE The optional heat kits use a power supply that is independent of the power supply of the air handler & blower. Please be aware of this when wiring the heat kit.

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Page 20

Indoor Unit Installation
Outdoor Unit Installation

4

NOTE: Install the unit by following local

codes and regulations, these may slightly

differ between regions.

Minimum Clearance

above unit:

24 in (60 cm)

7iMn9ifinrnoim(n2tu0om0f ctChmlee)aurannitc: e

Minimum Clearance between the back of the unit and wall:
Ground Installed: 12 in (30 cm)
Bracket Installed: 6 in (15 cm)

oMnintihmeulemftCsliedaeraonf ce unit: 12 in (30 cm)
Fig. 4.1
Installation Instructions ­ Outdoor Unit
Step 1: Select an Installation Location Before installing the outdoor unit, you must choose an appropriate location. Use the following guidelines to help you select an appropriate location.
Proper installation locations should meet following guidelines:
Meets all spatial requirements shown in the illustration above (Fig. 4.1) Good air circulation and ventilation Firm and solid location that can support the unit and will not cause vibration Noise from the unit will not disturb others
Protected from prolonged periods of exposure to direct sunlight or rain If installed in an area where snowfall is expected, take appropriate measures to prevent ice buildup and coil damage. If necessary, mount the unit on risers of at least 6 in (15 cm) or per local code to be above the average snowfall for the area.

oMnintihmeurmighCtlesiadreanocfe the unit: 24 in (60 cm)
DO NOT install unit in the following locations:
Near an obstacle that will block air inlets and outlets. Near a public street, crowded areas, or where noise from the unit will disturb others.
Near animals or plants that could be harmed by hot air discharge.
Near any source of combustible gas. In a location that is exposed to large amounts of dust. In a location exposed to excessive amounts of salty air.
In a location that exposes the unit to large amounts of forced water.

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Outdoor Unit Installation

SPECIAL CONSIDERATIONS FOR EXTREME WEATHER
If the unit is exposed to heavy wind: Install the unit so the air outlet fan is at a 90° angle to the direction of the wind. If needed, build a barrier in front of the unit to protect it from extremely heavy winds. Ensure the wind barrier does not block necessary airflow. See Fig. 4.2 and Fig. 4.3 below.
Strong wind

Strong wind

Fig. 4.2
Wind Baffle

Step 2: Install drain joint
Heat pump units require a drain joint if the unit is elevated. Before bolting the outdoor unit in place, you must install the drain joint at the bottom of the unit. NOTE: there are two different types of drain joints depending on the type of outdoor unit.
If the drain joint comes with a rubber seal (see Fig. 4.4 – A), do the following:
1. Fit the rubber seal on the end of the drain joint that will connect to the outdoor unit.
2. Insert the drain joint into the hole in the base pan of the unit.
3. Rotate the drain joint 90° until it clicks in place facing the front of the unit.
4. Connect a drain hose extension (not included) to the drain joint to redirect water from the unit during heating mode.
If the drain joint does not come with a rubber seal (see Fig. 4.4 – B), do the following:
1. Insert the drain joint into the hole in the base pan of the unit. The drain joint will click in place.
2. Connect a drain hose extension (not included) to the drain joint to redirect water from the unit during heating mode.

Fig. 4.3

Strong wind

If the unit is frequently exposed to heavy rain or snow: Build a shelter above the unit to protect it from the rain or snow. Be careful not to obstruct airflow around the unit. If the unit is frequently exposed to salty air (seaside): Use an outdoor unit that is specially designed to resist corrosion.
IMPORTANT
In areas where snowfall is prevalent, the use of risers or a stand to elevate the condenser above the snow line is required by local & national codes.

Base pan hole of outdoor unit
Seal
Seal

Drain joint (only use if elevated)

(A)

(B)

Fig. 4.4

DRAINAGE IN COLD CLIMATES

In cold climates, make sure that the drain hose is as vertical as possible to ensure swift water drainage. If water drains too slowly, it can freeze in the hose and flood the unit.

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Page 22

Outdoor Unit Installation

Outdoor Unit Dimensions

TOP VIEW

A

FRONT VIEW

W

Air Inlet

Air Inlet

D

B

H

Air Outlet
UNIT MOUNTING DIMENSIONS The following is a list of different outdoor unit sizes and the distance between their mounting feet. Prepare the installation base of the unit according to the dimensions in the table below, using the illustrations of the units above (Fig 4.5) as a guide to correspond with the table.

W 24K
Fig. 4.5

H 36K, 48K, & 60K

Outdoor Unit Model#

Outdoor Unit Dimensions: Inches (Millimeters)
Width (W) x Height (H) x Depth (D)

Mounting Dimensions:

Inches (Millimeters)

Width (A)

Depth (B)

CENTRAL-24-HP-C-230A00

37.24 in x 31.89 in x 16.14 in (946 mm x 810 mm x 410 mm)

26.50 in (673 mm)

15.87 in (403 mm)

CENTRAL-36-HP-C-230A00

37.48 in x 52.48 in x 16.34 in (952 mm x 1333 mm x 415 mm)

24.96 in (634 mm)

15.90 in (404 mm)

CENTRAL-48-HP-C-230A00

37.48 in x 52.48 in x 16.34 in (952 mm x 1333 mm x 415 mm)

24.96 in (634 mm)

15.90 in (404 mm)

CENTRAL-60-HP-C-230A00

37.48 in x 52.48 in x 16.34 in (952 mm x 1333 mm x 415 mm)

24.96 in (634 mm)

15.90 in (404 mm)

Step 3: Anchor Outdoor Unit The outdoor unit can be anchored to the ground or to a wall-mounted bracket using M-10 bolts. Prepare the installation base of the unit according to the dimensions in the table above. If you’re installing the outdoor unit on the ground or on a concrete platform, refer to the set of instructions to the right. Instructions for installing the outdoor unit to a wallmounted bracket are located on the next page.
When drilling into concrete, it is recommended to wear safety goggles, or some form of eye protection, in order to guard against the dust that will be created.

If you are installing the outdoor unit on the ground or a concrete mounting platform, use the following steps:
1. Mark the positions for four expansion bolts based on dimensions in the Mounting Dimensions chart and illustrations on the previous page.
2. Pre-drill holes for expansion bolts.
3. Clean concrete dust away from the holes.
4. Place a nut on the end of each expansion bolt.
5. Hammer expansion bolts into the holes you pre-drilled.
6. Remove the nuts from the expansion bolts, and place outdoor unit on bolts.
7. Put a washer on each of the expansion bolts, then reinstall the nuts.
8. Using a wrench, tighten each nut until snug.

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Outdoor Unit Installation
If you are installing the unit on a wall-mounted bracket, follow these steps:
Before installing a wall-mounted unit, make sure that the wall is made of solid brick, concrete, or a similarly strong material. The wall must be able to support at least 4 times the weight of the unit.
1. Mark the position of the bracket holes based on the dimensions in the Mounting Dimensions chart on the previous page.
2. Pre-drill the holes for the expansion bolts. 3. Clean dust and debris away from the holes. 4. Place a washer and nut on the end of each
expansion bolt. 5. Thread expansion bolts through the holes in
the mounting brackets. Then, put the mounting brackets in position and hammer the expansion bolts into the wall. 6. Check that the mounting brackets are level. 7. If the feet of the outdoor unit have rubber pads already installed, and you’re using a MRCOOL® wall-mounted bracket, remove them before attempting to mount the condenser to the bracket. The mounting bracket has rubber isolating pads on it that will take the place of these. 8. Carefully lift the unit and place its mounting feet on the brackets. 9. Then, bolt the unit firmly to the brackets.
TO REDUCE VIBRATION OF WALL-MOUNTED UNIT If allowed, you can install the wall- mounted unit with rubber gaskets to reduce vibration and noise.

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Page 24

Indoor Unit Installation
Drain Pipe Installation

5

The condensate drain pipe is used to drain condensate (water) away from the unit. Improper installation of the drain pipe could result in unit and/or property damage. A drain pipe is not included with this air handler and must be purchased separately.
NOTE ON PURCHASING DRAIN PIPE
Drain pipe installation requires a polyethylene tube (internally threaded tube 3/4 inch), which can be obtained at your local hardware store or dealer.
DO NOT pull the drain pipe forcefully as this could cause it to become disconnected. Insulate all piping to prevent condensation,
. which could lead to water damage. If the drain pipe is bent or installed incorrectly, water could leak and cause the
. water level switch to malfunction. In HEAT mode, the outdoor unit will discharge water. Ensure that the drain hose is placed in an appropriate area in order to avoid water damage and possibility of slipping.

Indoor Unit Drain Pipe Installation
These units operate with a negative pressure at the drain connections and a drain trap is required. The trap needs to be installed as close to the unit as possible. Make sure the top of the trap is below the connection to the drain pan to allow complete drainage of the pan. Please refer to Fig. 5.1 below as a guide.
1. Install the drain pipe into the main drain hole. Then, cover the drain pipe with heat insulation to prevent condensation from forming and leakage from occurring.
VERTICAL DISCHARGE

.IMPORTANT After removing drain pan plug(s), check the drain hole(s) to verify that the drain opening is fully open and free of any debris. Also ensure that no debris has fallen into the drain pan during the installation that could impede flow through the drain
. opening. Be sure to seal around the exiting drain pipe, as well as around the liquid and suction lines to prevent infiltration of
. humid air. The blower within this unit draws air through the coil rather than blowing air through it. This can cause the blower to draw air in through the drainage piping and into the air supply. In order to prevent this, traps must be installed in the drainage piping (primary & auxiliary, if used).

Primary Drain

Main drain hole
Fig. 5.1

Overflow drain hole

NOTE ON HORIZONTAL PIPE RUNS
Horizontal runs must also have an anti-siphon air vent (stand pipe) installed ahead of the horizontal run to eliminate any air trapping. Please see the Fig. 5.2 below.

2 in (50 mm) >2 in (50 mm)

Anti-siphon air vent

2 in (50 mm)

Vent T Lean over 1/50
Drain Trap

Fig. 5.2

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Drain Pipe Installation

NOTE ON DRAIN PIPE INSTALLATION
· When using an extended drain pipe, tighten the indoor connection with an additional protection tube to prevent it from pulling loose.
· The illustrations on the previous page show how to trap and plug all drains during vertical and right-hand discharge.
· The seal plug provided in the accessories should be screwed in and tightened by hand.
· Improper installation of the drain pipe could cause water to flow back into the unit and flood.
2. Next, using a 3.5 in (90 mm) core drill, drill a hole into the wall to allow the drain pipe to be routed to the exterior of the building. When drilling the hole, be sure to drill it at a slightly downward angle, so that the outdoor end of the hole is lower than the indoor end by roughly 0.5 in (12 mm). This will ensure proper drainage. Please refer to Fig. 5.3 below as a guide. NOTE: The wall hole will also be used to run the refrigerant piping/line set and wiring through that will connect the air handler to the outdoor unit.
NOTE ON DRILLING THE WALL HOLE
When drilling the wall hole, be sure to avoid wires, plumbing, and other sensitive components.
Wall

Outdoor

Indoor

NOTE ON DRAIN PIPE OUTLET
· The drain pipe outlet should be at least 1.9 in (5 cm) above the ground. If the drain pipe outlet is allowed to touch the ground, it could become blocked and cause the unit to malfunction.
· If you discharge the water directly into a sewer, make sure that the drain has a U or S pipe to catch odors that could come back into the building.

0.5 in (12 m m)
Fig. 5.3 3. Pass the drain pipe through the wall hole to the
exterior of the building. Ensure that it will drain to a safe location where it will not cause water damage or create a slipping hazard. 4. Once the entire installation is complete be sure to fill the remaining space of the hole with some sort of sealant (ex: spray foam).
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Page 26

Indoor Unit Installation
Refrigerant Piping Connections

6

Line Set Length Specifications

Unit: feet (meters)

Air Handler Capacity (BTU/hr)
Max. refrigerant pipe length

24K

36K

48K

60K

164.04 ft 213.25 ft 213.25 ft 213.25 ft (50 m) (65 m) (65 m) (65 m)

Max. height difference between 82.02 ft 98.42 ft 98.42 ft 98.42 ft

indoor and outdoor unit

(25 m) (30 m) (30 m) (30 m)

Outdoor unit

Maximum Height Difference Between the Indoor and Outdoor Unit

Indoor unit

24K Air Handler 82.02 ft (25 m)
36K-60K Air Handler 98.42 ft (30 m)

Indoor unit

24K Air Handler 82.02 ft (25 m)
36K-60K Air Handler 98.42 ft (30 m)

Fig. 6.1
IMPORTANT INSTALLATION INFORMATION!
Refrigerant Line Set Connection Options, Requirements, and Stipulations
24K/36K/48K/60K Capacity Units – These units are designed to be installed using either a traditional flare nut configuration of refrigerant piping or the optional MRCOOL® No-Vac® Quick Connect® Pre-Charged Line Set. If the optional No-Vac Quick Connect Line Set is used, you DO NOT have to retain the services of a professional HVAC installer. If the traditional flare nut configuration is selected, you ARE REQUIRED to retain the services of a professional HVAC installer. Stub pipes and copper nuts are included with these capacity units to complete this type of installation. If any other form of installation is attempted, or these stipulations are not followed, the WARRANTY WILL BE VOIDED.

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mrcool.com

Refrigerant Piping Connections
Conventional Line Set Installation

WARNING
· All field piping must be completed by a licensed technician and must comply with the local and national regulations.
· When the unit is installed in a small room, measures must be taken in order to prevent the refrigerant concentration in the room from exceeding the safety limit should refrigerant leakage ever occur. If refrigerant should leak and its concentration exceeds the proper limit, it may create hazards due to a lack of oxygen.
· When installing the refrigeration system, ensure that air, dust, moisture, or any other foreign substances do not enter the refrigeration circuit. Contamination within the system could cause the operating capacity of the unit to become poor or create high pressure in the refrigeration cycle, which could cause an explosion and/or personal injury.
· If refrigerant leakage should occur during the installation, ventilate the room immediately. Refrigerant gas is both toxic and flammable. Ensure there is no refrigerant leakage after completing the installation.

Note on Pipe Length and Elevation
Ensure that the length of the refrigerant piping, the number of bends, and the drop height between the outdoor and indoor units meet the requirements listed in the table below:

The Maximum Length and Drop Height

Based on Model Capacity

Units: feet (meters)

Type of Model

Capacity (Btu/h)

Length Maximum

of

Drop

Piping Height

North

America,

24K

Australia

and the

EU frequency

36K

conversion

48K

Split Type

60K

164 ft (50 m)

82 ft (25 m)

213 ft (65 m)

98.4 ft (30 m)

Oil Traps If oil flows back into the outdoor unit’s compressor, this could cause liquid compression or deterioration of the oil return. Installing oil traps in the rising gas piping can prevent this. Please refer to Fig. 6.2 below as a guide.
· For 24,000 Btu/h units, an oil trap should be installed every 20 ft (6 m) of vertical suction line riser.
· For units 36,000 Btu/h or greater, an oil trap should be installed every 32.8 ft (10 m) of vertical suction line riser.

Gas Piping Oil Trap

Indoor unit/ Outdoor Unit

Indoor unit/ Outdoor Unit
mrcool.com

Liquid Piping

20 ft (6 m) for units <36,000 Btu/h

32.8 ft (10 m) for units
36,000 Btu/h

Fig. 6.2

Page 28

Refrigerant Piping Connections

CAUTION
DO NOT install the connecting piping until the installation of the indoor and outdoor units have been completed. · Insulate both the gas and liquid piping in order to prevent water leakage.

Name

State

Connecting Pipe
Assembly

Liquid side Gas side

Capacity (Btu/h) 24K/36K/48K/60K
24K/36K/48K 60K

Connecting Refrigerant Piping
Step 1: Cut Pipes
When preparing refrigerant pipes, take extra care to cut and flare them properly. This will ensure an airtight seal, efficient operation, and, minimize the need for future maintenance.
1. Measure the distance between the indoor and outdoor units.
2. Using a pipe cutter, cut the pipe a little longer than the measured distance.
3. Ensure the pipe is cut at a perfect 90° angle. Please refer to Fig 6.3 below for cut examples.

90°

Oblique Rough Warped

Fig. 6.3
CAUTION
DO NOT deform pipe while cutting. Be extra careful not to damage, dent, or deform the pipe while cutting. This will drastically reduce the heating efficiency of the unit.
Step 2: Remove Burrs Burrs can affect the airtight seal of the refrigerant piping connection. They must be completely removed by following these steps:

1. Hold the pipe at a downward angle to prevent
   burrs from falling into the pipe. 2. Using a reamer or deburring tool, remove all
   burrs from the cut section of pipe. Refer to Fig. 6.4 above.

Piping Diameter

Note

3/8 in (9.52 mm) *When installing the 60K, the gas side of the AHU is

3/4 in (19 mm)

3/4 in (19 mm), a 3/4 in (19 mm) to 7/8 in (22 mm)

7/8 in (22 mm)*

stub pipe is included in the AHU accessories.

Pipe

Reamer

Point downward

Fig. 6.4 Step 3: Flare Pipe Ends Proper flaring is essential to achieve an airtight seal. 1. After removing burrs from the cut pipe, seal the
ends with PVC tape to prevent foreign materials from entering the pipe. 2. Sheath the pipe with insulating material. 3. Place flare nuts on both ends of the pipe. Ensure they are facing the correct direction because once the pipe is flared you will be unable to change their direction.
Flare nut
Copper pipe
4. Remove the PVC tape from the ends of the pipe right before performing flaring work.
5. Clamp the flare form on the end of the pipe to be flared. The end of the pipe must extend beyond the flare form. Please refer to Fig. 6.5 below. Flare form

Pipe Fig. 6.5

Page 29

mrcool.com

Refrigerant Piping Connections

6. Place flaring tool onto the form. 7. Turn the handle of the flaring tool clockwise until
the pipe is fully flared. Flare the pipe in accordance with the dimensions in the table and Fig. 6.6 below.
FLARE SHAPE
90°±4 45°±2
A

5. While firmly gripping the nut on the unit tubing with the spanner, use an HVAC torque wrench to tighten the flare nut (Fig 6.7 below). Continue to tighten the flare nut with the torque wrench until specified torque rating listed in the table to the left is reached.

R 0.4~0.8

Fig. 6.6

PIPING EXTENSION BEYOND FLARE FORM

Pipe gauge

Tightening Torque
lb-ft (Nm)

Flare dimension (A) Inch (millimeter)

Min.

Max.

Ø 3/8 in

23.6-28.8 lb-ft (32-39 Nm)

0.52 in (13.2 mm)

0.53 in (13.5 mm)

Ø 3/4 in

49.4-74.5 lb-ft (67-101 Nm)

0.91 in (23.2 mm)

0.93 in (23.7 mm)

Ø 7/8 in

62.7-81.1 lb-ft (85-110 Nm)

1.04 in (26.4 mm)

1.06 in (26.9 mm)

8. Remove the flaring tool and flare form, then inspect the end of the pipe for cracks and even flaring.

Step 4: Connect Pipes
In this step you will connect the copper refrigerant pipes to the indoor unit first, and then to the outdoor unit. The low pressure pipe should be connected first and then the high pressure pipe can be connected. NOTE: If you are installing a 60K capacity air handler, please refer to the instructions on the next page as it requires additional steps. 1. When connecting the flare nuts, apply a thin coat
of refrigerant oil to the flared ends of the pipes. 2. Align the center of the two pipes that are to be
connected.

Indoor unit tubing Flare nut Pipe 3. Tighten the flare nut by hand as tightly as possible. 4. Using a spanner, grip the nut on the unit tubing.

Fig. 6.7
NOTE ON TIGHTENING TORQUE When torquing the flare nut be sure to use the correct torque rating according to the table. DO NOT overtighten the flare nut as this could damage it and under tightening it could also cause it to leak. 6. Then, carefully route and bend the piping to the
exterior through the wall hole so it can be connected to the outdoor unit. For more detailed information about bending the piping and the minimum pipe radius please refer to the note and Fig. 6.8 below. NOTE ON MINIMUM BEND RADIUS Carefully bend the refrigerant piping in the middle according to the illustration below. DO NOT bend the piping at an angle greater than 90° or more than 3 times as it could become damaged and/or break.
Bend the pipe using your thumbs
Minimum Bend Radius: 3.9 in (10 cm) Fig. 6.8
7. Then, connect the refrigerant piping to the outdoor unit by repeating steps 1-5.
8. Evacuate air and moisture from the refrigerant lines. Please refer to the Air Evacuation & Adding Refrigerant section of this manual for more detailed instructions for completing this step.
9. Open the stop valves of the outdoor unit to start the flow of the refrigerant between the indoor and outdoor unit.

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Page 30

Refrigerant Piping Connections

CAUTION

Once the refrigerant piping is connected and the installation of the indoor and outdoor units has been completed, perform leak tests to ensure the system is not leaking. Should you detect a refrigerant leak, ventilate the area immediately and evacuate the system (refer to the Air Evacuation section of this manual).
9. Once the unit is installed, and you have confirmed the system does not leak, insulate and wrap all the piping, including the valve bodies with thermal insulation material to prevent condensation. Ensure the valve is sealed. Please refer to Fig. 6.9.

Fig. 6.9

Thermal insulation material

CAUTION
Ensure insulation is properly wrapped around the piping. Direct contact with bare piping may result in burns or frostbite.

60K Indoor Air Handler Piping Connection Instructions
When connecting refrigerant piping to a 60K capacity air handler additional steps are required. Complete the piping connections to the indoor unit as shown below. Only use flare-to-braze 3/4″ to 7/8″ & 3/8″ to 3/8″ connect the 7/8″ line set. If you attempt to connect the line set in any other manner than the one shown below, it will cause the performance of the unit to decrease.

3/8″ Service valve

3/8″ Line set

Flare-to-braze (3/8″ to 3/8″ Stub Pipe)

3/4″ Service valve

7/8″ Line set

Flare-to-braze (3/4″ to 7/8″ Stub Pipe)

Page 31

mrcool.com

No-Vac® Quick Connect® Line Set* Installation

INSTRUCTIONS FOR USE WITH NO-VACTM QUICK CONNECT® LINE SET* SOLD SEPARATELY
KINK RESISTANT, PRECHARGED, SIMPLE SECURE QUICK CONNECT, 100% CONNECTION GUARANTEE

Please read and follow the instrucons and diagram below* : Connecons must be made exactly as specified to avoid system leaks and /or damage

IMPORTANT

1. Take out matching male connectors M1 and M2. 2. Remove protecve cap with the copper gasket at each stop valve on the CONDENSER
and ensure the threads are clean and complete. 3. Tighten the M1 connector to the cutoff valve *1 with a ghtening force of 37 /lb (50 Nm).

When running the Line Set through the knockout hole of the condenser, it may be necessary to slightly trim the line set insulation so it feeds

Tighten the M2 connector to the cutoff valve *2 with a ghtening force of 52 /lb (70 Nm). through the hole freely. Otherwise,

4. Repeat step 3 for AIR HANDLER at the other end of the LINE SET.

it may be difficult to connect it to

5. Unroll and route the LINE SET between the AIR HANDLER and the CONDENSER. Bend the line the condenser. Once the installation

set piping by hand to route the line set to suit your applicaon. Use care when bending the line is complete, pack the hole with

set. Please refer to the Bending the Line Set secon of Pg. 13 for more detailed

neoprene to prevent small animals

instrucons on how to properly and safely bend the line set refrigerant piping, as well as the and insects from entering the

correct bend radius.

condenser.

6. Remove the protecve caps of the valves at both ends of the LINE SET. Verify that all threads

are clean and complete.

NOTE ON WRENCHES

7. Tighten the LINE SET F1 valve to the M1 Connector (aached in step 3) with a force of 33 /lb (45 Nm). Tighten the LINE SET F2 valve to the M2 Connector (aached in step 3) with a ghtening force of 33 ft/lb (45 Nm).
8. Repeat this process for the AIR HANDLER at the other end of the LINE SET. 9. At the OUTDOOR UNIT remove the protecve cap at the cutoff valve switch and open the
stop/cutoff valve with a hex wrench to release refrigerant into the system. If there is any fizz, grease or other leakage, then close the valve immediately and check that steps 3 and 7 were done properly. Otherwise, using a sponge or spray bole, apply a soapy water soluon to the connecon points to check for micro leaks. If any bubbles form it indicates there is a leak. If this does occur, close the valve immediately and check that steps 3 and 7 were done properly and re-ghten the valves and line set if necessary.
10. Aer the correct connecon, re-ghten the cutoff valve’s protecon cap and cover the M1, M2 and F1, F2 connecons with the gray insulang sleeve to help prevent condensaon.

The wrench sizes needed for tightening the No-Vac® Quick Connect® Line Set are listed below. However, based on the availability of the wrench sizes needed, it is recommended to use two large crescent (adjustable-type) wrenches. Using one to hold the valve while using the other wrench to tighten the line set connector.

Piping Size Wrench Size Required (Stamped on piping) Standard Metric

3/8″

1″

25 mm

3/4″

1-3/8″ 35 mm

Or 2x large crescent (adjustable-type) wrenches

Allen/Hex Wrench Sizes Needed To Open Stop/Cutoff Valves

Piping/Valve Size (Stamped on piping)

Allen Wrench Size

IMPORTANT
The stop/cutoff valves on the unit must be opened AFTER connecting the lines and BEFORE turning on the unit. Otherwise, operation can

Complete unit replacement using the No-Vac® Quick Connect® lines

3/8″

5 mm

cause leakage and/

3/4″

8 mm

or damage to the unit.

50 N *1
3/8″
M1 F1

70 N *2
3/4″
M2

F2

*1

M1 F1

50 N 3/8″

*2

M2 F2

70 N

3/4″

Air Handler

Condenser

Open the stop valve only after connecting the refrigerant lines

Connect using precharged line set with Quick Connect® fittings in lengths 15, 25, 35, 50 feet

Failure to follow the instructions provided could result in severe harm to you, this product, or other property. The manufacturer, distributor, and seller are not responsible for any harm resulting from the failure to follow instructions and the failure to follow these instructions will void any and all warranties express or implied. *Pat. https://mrcool.com/mrcool-patents/
mrcool.com

www.mrcool.com

A-coil Precharged with R-410A Refrigerant
Page 32

Electrical Connections

7

BEFORE PERFORMING ELECTRICAL WORK, READ THESE REGULATIONS
NOTE: ELECTRICAL WORK MUST BE COMPLETED BY A QUALIFIED TECHNICIAN!
DO NOT connect any other equipment to the power circuit for the unit. Only connect the unit to an individual branch circuit.
DO NOT allow wires to touch or rest against the refrigerant piping, compressor, or any other moving parts within the unit.
1. All wiring must comply with local and national electrical codes, regulations, and must be installed by a licensed electrician.
2. All electrical connections must be made according to the Electrical Connection Diagram located on the panels of the indoor and outdoor units.
3. If there is a serious safety issue with the power supply, stop work immediately. Explain the issue to the client, and refuse to continue the installation until the safety issue is properly resolved.
4. Power voltage should be within 90-110% of the rated voltage. An insufficient power supply can cause a malfunction, electrical shock, and/or fire.
5. If connecting power to fixed wiring, a switch or circuit breaker that disconnects all poles, and has a contact separation of at least 1/8 in (3 mm), must be incorporated in the fixed wiring. The qualified technician/electrician must use an approved circuit breaker or switch.
6. The circuit, including any switches, should have a capacity 1.5 times the maximum unit current (amps).
7. Installation of an external surge suppressor at the outdoor disconnect is recommended. 8. Make sure the unit/system is properly grounded. 9. Every wire must be firmly and securely connected. Loose wiring can cause the terminal to overheat,
which could result in a malfunction and/or fire. 10. If the unit has an auxiliary electric heater, it must be installed at least 40 in (1 m) away from
combustible materials. 11. To avoid electrical shock, never touch the electrical components soon after the power supply has
been turned off. Always wait 10 minutes or more before touching the electrical components once the power has been turned off. 13. Ensure that the electrical wiring and signal wiring do not cross. This could cause distortion, interference, or possibly damage to the circuit boards 14. The unit must be connected to the main outlet. Normally, the power supply must have an impedance of 32 ohms. 15. Connect the outdoor wires before connecting the indoor wires.

BEFORE PERFORMING ANY ELECTRICAL WORK, TURN OFF ALL POWER TO THE SYSTEM!
NOTE: The wire colors of this series/model may differ from previous models, other series and general conventions. All wiring must be performed in accordance with the wiring diagram on the back of the wiring cover of the outdoor condenser and/or the wiring diagrams found in this section of the manual.

PPaaggee3393

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Electrical Connections

IMPORTANT!
Depending upon the capacity of unit and accessories (electric heat kit, wired thermostat, etc.) being installed, additional electrical components (circuit breakers, conduit, air switch, etc.) and wiring may need to be purchased separately to properly connect the system. Selection and installation of these components and wiring should only be performed by a qualified technician.
Outdoor Unit Wiring & Electrical Specifications
SELECT THE CORRECT CABLE TO CONNECT THE POWER SUPPLY TO THE OUTDOOR UNIT
· See table below for gauge requirements of power cables for outdoor condenser. NOTE: The table below is a standard chart, the AWG ratings and wiring needs will change based on wire length and temperature.

Minimum Wire Gauge for Power Cables

Model Appliance Capacity Amps (A) (BTU/hr) MCA MOP

Single-Zone Condensers

24K

25 35

36K

41 50

48K

42 50

60K

44 60

Indoor Unit Wiring & Electrical Specifications (for units without optional electric heat kit)

Unit Capacity

Volts-Phase

24K

208/230-1

Rated Input Current of Power Conversion
Equipment Amps
3.0

BRANCH CIRCUIT

Minimum Circuit Amps

Minimum Wire Size (AWG*)

Fuse/ Circuit Breaker
Amps

4.0

14#

15.0

36K

208/230-1

4.0

5.0

14#

15.0

48K

208/230-1

6.0

7.5

14#

15.0

60K

208/230-1

7.0

9.0

14#

15.0

• Use copper wire only to connect the unit. If anything other than uncoated (non-plated) 75°C copper wire (solid wire for 10 AWG and smaller, stranded wire for larger than 10 AWG) is used consult the applicable tables of the National Electric Code (ANSI/NFPA 70).

NOTE
· If branch circuit wire length exceeds 100 ft, consult NEC 210-19a to determine maximum wire length. Use a 2% voltage drop.
· If the unit is to have an electric heat kit installed (optional), please refer to the Installation of Air Handler Heat Kit section of manual for more detailed information regarding the electrical specifications.

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Page 34

Electrical Connections

Air Switch Diagram

Air switch diagram (shown with optional electric heat kit)

Service Disconnect

(purchased separately)

Service Disconnect

Indoor unit power wires

(purchased separately)

Outdoor unit

power wires

Outdoor unit

Indoor unit

Serivce Disconnect (purchased separately)
Electric heat kit power wires
Electric heat kit

cables connecting indoor unit to outdoor unit purchased separately

Fig. 7.1

NOTE: Diagram shown is for illustration/reference purposes only.

NOTE ON AIR SWITCH

· When the maximum current of the air conditioner is more than 16A, a service disconnect with protective device shall be used (purchased separately). Refer to Fig. 7.1.
Systems in the North American market should be wired according to NEC & CEC requirements and state & local regulations.
Please note that units that are equipped with an optional heat kit, the heat kit uses a power supply that is independent of the power supply of the air handler & blower. This power supply may also require an air switch as well. Please be aware of this when wiring the heat kit.

Outdoor Unit Wiring
The wiring and other electrical components (insulation or conduit) to connect the indoor and outdoor units must be purchased separately. Please refer to the beginning of Electrical Connections section of the manual for wiring specification guidelines. Follow the steps below to wire the outdoor condenser. NOTE: For more detailed illustrations of the different variations of wiring connections, depending on your specific application, please refer to the wiring diagrams further in this section of the manual.
1. Prepare the cables for connection.
a. Select the correct cable size based on the unit being installed. Ensure to size each wire used so that is several inches longer than the required length for wiring. This will allow for some slack and prevent the wire from being under tension.
b. Using wire strippers, strip the jacket from each end of the cable to reveal approximately 6 in (15 cm) of wire.
c. Strip the insulation from the ends of the wire.
d. Stranded wire requires u-lugs or ring terminals to be crimped onto the ends of the wire.
2. Remove the 3 screws from the electrical wiring cover on the outdoor condenser. Then, remove the cover, as shown in the image below. NOTE: Wiring connections must strictly follow the diagram found inside the wiring cover.

NOTE ON CABLE RECOMMENDATIONS The type of cable that is selected to wire the indoor and outdoor unit are based on local electrical codes and regulations. The recommended gauge (AWG) of the cables used should be based the Minimum Circuit Ampacity (MCA) and Maximum Overcurrent Protection (MOP) ratings. These are indicated on the nameplate of the outdoor unit and listed in the tables at the beginning of this section of the manual.
Please select the appropriate through-hole according to the diameter of the wire.

Page 35

mrcool.com

Electrical Connections

Outdoor Unit Wiring
WARNING
The risk of electric shock can cause injury or death. Disconnect all remote electric power supplies before servicing. 3. Remove the caps on the conduit panel. 4. Mount the conduit tubes (not included,
purchased separately) onto the conduit panel. 5. Properly connect the wiring by securely fastening
the u-lug or ring terminal of each wire to the corresponding terminal on the terminal block as shown below.
L1 L2

WARNING
Isolate the power wires and communication wires by the strain relief and ensure they have enough slack. Keep them separated and DO NOT allow them to intertwine. If this occurs it could create interference and cause the unit to malfunction.
6. Ensure the unit is properly grounded in accordance with any and all state and local codes.
7. Ensure all wiring is properly insulated and protected in accordance with any and all state and local codes.
8. Then, reinstall the electrical wiring cover by positioning it into place and reinstalling the screws. Once complete, route the indoor unit wiring to the air handler.

OPTIONAL

TO POWER SOURCE
Outdoor Unit Wiring for Condenser

Outdoor Unit

Indoor Unit Wiring

1. Prepare the cables for connection.
a. Using wire strippers, strip approximately 6 inches (15 cm) of the outside rubber jacket.
b. Once rubber jacket section is removed, strip the same length of interior insulation from the end of the wire.
2. Open the front panel of the indoor unit. Then, using a screwdriver, remove the cover of the electric control box of the indoor unit.
3. Route and thread the power and communication cables through the wire outlet.
4. Properly connect the wiring by securely fastening the u-lug or ring terminal of each wire to the corresponding terminal on the terminal block. Refer to the unit serial number and the wiring diagram located on the electric control box cover (Fig. 7.2). NOTE: For more detailed illustrations of the different variations of wiring connections, depending on your specific application, please refer to the wiring diagrams on pages 47-50.
5. Clamp down the cable with the cable clamp. The cable must not be loose or pull on the u-lugs.
6. ReaWttaAcRhNthIeNeGlectric control box cover.

Isolate the power wires and communication wires and keep them separated to ensure they DO NOT intertwine as this could cause the unit to malfunction.

Class 2 wire

L1 L2

Power wire

TO POWER SOURCE

Wiring diagram
Fig. 7.2
CAUTION
· While connecting the wires, strictly follow the wiring diagram.
· The refrigerant circuit can become very hot. Keep all wiring and cables away from the copper piping.

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Page 36

Electrical Connections

Wiring Diagrams & Connection Methods
The wiring diagrams below and on the following pages show the proper wiring and DIP switch settings (for indoor and outdoor units) depending upon your application and the type of thermostat used (standard wired controller or 24V thermostat).

Scenario

Controller

Indoor Unit

Connection between indoor & outdoor units

Outdoor Unit

AHU DIP switch

ODU DIP switch

SW1-1 SW1-4

S1-2

Scenario 1 (Recommended)

Wired controller (Standard)

Air handler

RS485: S1/S2

Standard

OFF

OFF

OFF

outdoor unit (Default) (Default) (Default)

Scenario 2 24V Thermostat Air handler

RS485: S1/S2

Standard outdoor unit

ON

OFF

OFF

(Default) (Default)

Scenario 3

24V Thermostat

Air handler

24V: R/C/B/Y1/Y2/G/W

Standard outdoor unit

ON

ON

ON

Scenario 4

24V Thermostat

Air handler

24V: R/C/B/Y1/Y2/G/W

Third party outdoor unit

ON

ON

n/a

NOTE: Adjust dip switch settings before powering on the unit.

Scenario 1: Standard & Recommended

HA/HB

Wired controller (Standard)

AHU Indoor unit

S1/S2

Standard Outdoor unit

Open the rear cover

HA/HB

S1/S2

Wired

Indoor unit

controller R C G Y1 Y2 B W W1W2 E DH L S1 S2

Wired controller

R C Y1 Y2 B W D L S1 S2
Outdoor Unit

Non-polarity RS485 communication

SW1 ON
1 23 4

208/230-1-60

Page 37

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Electrical Connections

Scenario 2:

24V

24V Thermostat

AHU Indoor unit

S1/S2

Standard Outdoor unit

24V Thermostat

R
C G Y1 Y2
B W W1 W2 E DH
L

24V

S1/S2

SW1-1 DIP switch in the “ON”position

Indoor unit R C G Y1 Y2 B W W1W2 E DH L S1 S2

Default Setting

SW1 ON

R C G Y1 Y2 B W W1W2E DH L R C Y1 Y2 B W D L S1 S2

24V Thermostat

Outdoor Unit

1 23 4

Non-polarity RS485 communication

208/230-1-60

NOTE: Adjust dip switch settings before powering on the unit.

Scenario 3 24V
24V Thermostat

24V

AHU Indoor unit

Standard Outdoor unit

24V Thermostat

R
C G Y1 Y2
B W W1 W2 E DH
L

24V

24V

SW1-1 DIP switch in the “ON”position
SW1-4 DIP switch in the “ON”position

Indoor unit R C G Y1 Y2 B W W1W2 E DH L

R C G Y1 Y2 B W W1W2E DH L 24V Thermostat
24V communication

R C Y1 Y2 B W D L Outdoor Unit

NOTE: Adjust dip switch settings before powering on the unit.

S1-2 DIP switch in the”ON” position
SW ON
1 23 4

SW1 ON
1 23 4

208/230-1-60

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Page 38

Scenario 4: 24V Thermostat

Electrical Connections

24V

24V

AHU Indoor unit

The third party Outdoor Unit

24V Thermostat

R

C

24V

G

Y1

Y2

B

W

W1

W2

E

DH

L

Outdoor Unit

R

C

24V

Y1

Y2

B

W

D

L

Indoor unit R C G Y1 Y2 B W W1W2 E DH L

R C G Y1 Y2 B W W1W2 E DH L 24V Thermostat
24V communication

SW1 ON
1 23 4

208/230-1-60

SW1-1 DIP switch in the “ON”position
SW1-4 DIP switch in the “ON”position

NOTE: Adjust dip switch settings before powering on the unit.

Wiring Diagrams & Connection Methods (Without Communication)

Connection Method C (36K-60K units ONLY): The following wiring diagrams are suitable for the AHU and outdoor condenser when used with a 24V thermostat without communication.
NOTE
· This equipment uses B functionality. The terminal is energized for heating functionality. Please ensure thermostat is setup for B functionality.

Wiring for 4H and 2C thermostat

W2 W1/E O/B
Y2 Y1 G L C R DH

THERMOSTAT

DH R C L G Y1

B W W1 W2 E

R C Y1 Y2 B W D L

INDOOR UNIT

OUTDOOR UNIT

S4-2 DIP switch off

S4-1 DIP switch off

Perform disconnection and

Disconnect and short

short-circuit to achieve

circuit to realize heating

partition, control or dehumidification segment

Wiring for 3H and 1C thermostat

W2 W1/E O/B
Y G L C R DH

THERMOSTAT

DH R C L G Y1

B W W1 W2 E

R C Y1 Y2 B W D L

INDOOR UNIT

OUTDOOR UNIT

S4-2 DIP switch off Perform disconnection and short-circuit to achieve partition, control or dehumidification

S4-1 DIP switch off Disconnect and short circuit to realize heating segment

Wiring for 3H and 2C thermostat

E O/B Y2 Y1 G
L C R DH

THERMOSTAT

DH R C L G Y1

B W W1 W2 E

R C Y1 Y2 B W D L

INDOOR UNIT

OUTDOOR UNIT

S4-2 DIP switch off Perform disconnection and short-circuit to achieve partition, control or dehumidification

Emergency heating control two groups of electric heating at the same time

Page 39

mrcool.com

Electrical Connections

Wiring Diagrams & Connection Methods Wiring for 3H and 2C thermostat

W1/E O/B Y2 Y1
G L C R DH
THERMOSTAT

DH R C L G Y1

B W W1 W2 E

INDOOR UNIT

R C Y1 Y2 B W D L

S4-2 DIP switch off Perform disconnection and short-circuit to achieve partition, control or dehumidification

S4-1 DIP switch off Disconnect and short circuit to realize heating segment

Wiring for 2H and 2C thermostat

O/B Y2 Y1 G C R
THERMOSTAT

DH R C L G Y1

B W W1 W2 E

INDOOR UNIT

R C Y1 Y2 B W D L OUTDOOR UNIT

Wiring for 2H and 1C thermostat

W/E O/B
Y G C R
THERMOSTAT

DH R C L G Y1

B W W1 W2 E

INDOOR UNIT

R C Y1 Y2 B W D L OUTDOOR UNIT

S4-1 DIP switch off Disconnect and short circuit to realize heating segment

Wiring for 1H and 1C thermostat

W Y G C R
THERMOSTAT

DH R C L G Y1

B W W1 W2 E

INDOOR UNIT

R C Y1 Y2 B W D L OUTDOOR UNIT

NOTE: This the least preferred method of control wiring and should only be used for emergency situations. Full comfort capacity may not be achieved using this method.

Wiring for Optional Functions

Alarm interface
Liquid level switch interface

Indoor and

outdoor unit

communication

Liquid Level Switch:

interface

This unit has a liquid level detection interface. If you

choose to incorporate this function, it will be necessary

to purchase a liquid level switch separately, connect it

to the CN5 interface, and remove J1. When the water

receiving pan is full, the water level switch will become

disconnected. Then, the water level switch sends a

signal and the unit will stop operating.

CN5 J1

WATER LEVEL SWITCH The Fault Warning

CN33

ALARM
Alarm Output: An alarm output (CN33) can be utilized if actions are required when a fault is present. This is a passive outlet port, so you will need to input a voltage signal. The relay is normally open during normal operation. It closes when a fault condition is active.

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Page 40

Electrical Connections

Wiring for Optional Functions (cont’d) Humidification Control Wiring:

WORK

HUMIDISTAT

TO HUMIDIFIER

CN23

24V control signal or 208/230V power supply

HUMIDISTAT G
24-VAC C

TO HUMIDIFIER

To connect a humidifier, utilize the passive signal “WORK” output (CN23) port, as well as the G and C wires on the controller, and wire the humidistat and humidifier per the above wiring diagram. When the fan is running, the CN23 relay will be closed which will allow power to be routed to the humidifier when the humidistat is below the humidity setpoint. If the thermostat or zone controller has a HUM interface, connect the humidifier directly to the HUM and C ports.

Dehumidification Control Wiring:

S4

ON

DH

12

R

HUMIDISTAT

Control Logic

Indoor Unit Connector

Connector R C G Y Y/Y2 B W W1 W2 E/AUX DH/DS/BK L

Purpose 24V Power Connection Common Fan Control Low Cooling High Cooling Heating Reversing Valve Heating Control Stage 1 Electric Heating Stage 2 Electric Heating Emergency Heating Dehumidification/Zoning Control System Fault Error

Outdoor Unit Connector

Connector R C Y1 Y2 B W D L

Purpose 24V Power Connection Common Low Cooling High Cooling Heating Reversing Valve Heating Control Defrost Heat System Fault Error

Dehumidification control requires an external humidistat at DH and R. Set the S4-2 dip switch to OFF. When the humidity rises and exceeds the set value of the humidistat, the 24V signal of DH changes to 0V, the cooling system then begins the dehumidification operation, and the air volume drops to 80% of the nominal cooling air volume.

LED Display
The control displays unit status as well as any active fault codes on the LED display. If the unit is functioning normally, the LED will display the current temperature setpoint. Or, if a 24V thermostat is used, a functional display code from the table on the following page will be shown. When a fault code is active, the display will flash the active code.
Please refer to the fault code table located in the troubleshooting section of the Service Manual for more detailed fault code information.

Page 41

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Electrical Connections

Functional Display

Mode

Priority G Y1 Y/Y2 B W W1 W2 E/AUX DH/DS/BK Display

Shut down

/

00 0 00 0 0

0

00

Fan

10 0 00 0 0

0

1

7

01

Fan

10 0 00 0 0

0

0

Cooling

*1 0 00 0 0

0

1

02

Cooling 2 Dehumidification 1

** 1 00 0 0

0

1

03

6

*1 0 00 0 0

0

0

04

Dehumidification 2

** 1 00 0 0

0

0

05

Heating 1

*1 0 10 0 0

0

1

06

Heating 2 Heating 2

5

** 1 10 0 0

0

1

07

* *1 0 0

0

1

Electric heating 1 Electric heating 1

*0 0 00 1 0

0

08

3

*0 0 00 0 1

0

Electric heating 2

*0 0 00 1 1

0

09

Heating 1 + electric heating 1

*1 0 10 1 0

0

1

Heating 1 + electric heating 1

*1 0 10 0 1

0

1

Heating 2 + electric heating 1 Heating 2 + electric heating 1

** 1 10 1 0

0

1

10

* *1 1 0

0

1

Heating 2 + electric heating 1 4

** 1 10 0 1

0

1

Heating 2 + electric heating 1

* *1 0 1

0

1

Heating 1 + electric heating 2

*1 0 10 1 1

0

1

Heating 2 + electric heating 2

** 1 10 1 1

0

1

11

Heating 2 + electric heating 2

* *1 1 1

0

1

Emergency heating

1

1

12

Heating zone control

1 0 10 *

0

0

Heating zone control

2

* 1 10 *

0

0

13

Heating zone control

* 1 *

0

0

NOTES: · 1 = signal, 0 = no signal · The terminal input signal is stable for 1 second before confirmation.

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Page 42

R C L G Y1 Y/Y2 B W W1 W2 E/AUX DH

DIP Switch Definitions

Electrical Connections

Function rotary switch Address DIP switch

S2

S3

1 2

ON

24V Thermostat interface

S1

24V Control DIP switch

SW1 SW2 SW3

ON

1 2 3 4 1 2 3 4 1 2 3 4 SW4 1 2 3 4

E Y X

Function DIP switch Static pressure DIP switch Page 43

ON

ON

ON

Fig. 7.3 mrcool.com

Electrical Connections

Function DIP Switch Settings

The 24V thermostat mode needs to refer to the following DIP switch settings.

SW1

SW2

SW3

SW4

S4

ON

ON

ON

ON

ON

1 2 3 4 1 2 3 4 1 2 3 4 1 2 3 4 12

SW4-1 · 000 is the default

SW4-2 SW4-3

· 000/001/010/011/100/101/110/111, internal machines with different abilities, electric heating and PSC classification for use

NOTE: The SW4 DIP switch is only for use by certified service technicians for the purpose debugging and adjusting the system, please DO NOT touch it.

Indoor Unit Dial Code

NO.

Dial code

Features

ON

OFF

1 SW1-1 Whether 24V thermostat is used or not.

YES

NO

2 SW1-2 Anti-cold blow protection option.

NO

YES

3 SW1-3 Single cooling/heating and cooling options. Cooling

Cooling & Heating

4 SW1-4 Stand alone indoor unit or full system.

Indoor unit only

Full system

5 SW2-1 First stage auxiliary heating.

1.8°F (1°C)

3.6°F (2°C)

6 SW2-2 Electric heat on delay.

30 minutes

15 minutes

7 SW2-3 Electric auxiliary heating delay to start time. YES

NO

8

SW2-4

Compressor / Auxiliary heat outdoor ambient lockout.

The heater will not operate if the outdoor temperature is greater than the temperature set by S3.

The compressor will not operate if the outdoor temperature is lower than the temperature set by S3.

Maximum continuous runtime allowed

before system automatically stages up

9

SW3-1

capacity to satisfy set point. This adds 32.9 to 37.4°F (0.5 to 3.0°C) to the user set point

30 minutes

in the calculated control point to increase

capacity and satisfy user set point.

90 minutes.

10

SW3-2

Cooling and heating Y2 temperature differential adjustment.

1.8°F (1°C)

3.6°F (2°C)

11

SW3-3

Temperature differential to activate second stage auxiliary heating.

3.6°F (2°C)

5.4°F (3°C)

12

Rotary Switch
S3

Set outdoor temperature limitation (for auxiliary heat or compressor).

0 means that the temperature protection is not turned on, 1-F is -4-46°F (-20-8°C) respectively, and each scale represents 3.6°F (2°C).

13 S4-1 Default ON.

Short circuit W1 and W2.

W1, W2 separate.

14 S4-2 DH function selection.

DH is off by default. DH on.

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Page 44

Electrical Connections

Outdoor Unit DIP Switch Setting

NO. Dial code

Features

1

SW-1

Metering device location

2 SW-3 Communication setting

3

SW-3

Strong cold and strong heat function

4 SW-4 Function to be defined

ON

OFF

Outdoor throttling (normally Indoor throttling(normally

closed single-way solenoid closed single-way solenoid

valve is not powered on).

valve store).

24V communication scheme 485 communication scheme

The cooling/heating target pressure compensation value is valid.

The cooling/heating target pressure compensation value is invalid.

Address DIP Switch
Address dialing S1+S2: When the user uses the centralized controller, the address dialing is required.
Network address: The address silkscreen is NET address, which is composed of a 16-bit address rotary code S2 plus a two-digit DIP switch S1 (set during electrical installation, no network function needs to be set).
· When S2 is 00 (the dialing code is not connected), the address value is the value of S2.
· When S2 is 10 (corresponding to the switch of the hardware connected to the 10K resisitor), the network address value is S2 plus 32.
· When S2 is 01 (corresponding to the dial code of the 5.1K resistor connected to the hardware is turned on), the network address value is the value of S2 plus 16.
· When S2 is 11 (all dialing codes are on), the network address value is the value of S2 plus 48.

Determined by dial code S2 1-10K 2-5.1K

S2 DIP switch selection

Website address

ON
S2 + 48
12

ON
S2 + 32
12

ON
S2 + 16
12
ON
S2
12

Model 24K 36K 48K 60K

SW4-1, 2, 3, setting (default)
Air Volume (CFM) 880
15KW 1320 20KW
1760 20KW
2195 – –

Air volume table

001 Air Volume
(CFM) 850
8KW, 15KW 1255 15KW
1675 10KW, 15KW
2055 15KW, 20KW

010 Air Volume
(CFM) 830
8KW, 10KW 1190
8KW, 10KW
1580 8KW, 10KW
1920 10KW, 15KW

011 Air Volume
(CFM) 800 5KW 1125
5KW, 8KW
1490 8KW
1775 10KW

NOTES
The airflow DIP switch can only change the air volume when the electric heat is turned on, and the unit cooling & heating air volume remains unchanged. If the DIP switch setting is incorrect, the default airflow will be run.

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mrcool.com

Electrical Connections

High, medium and low air volume parameters

24K

Fan speed
Low
Mid
High

Static pressure (Pa/in WC)
0/0 25/0.1 37/0.15 50/0.2 75/0.3 100/0.4 125/0.5 150/0.6 200/0.8 250/1.0
0/0 25/0.1 37/0.15 50/0.2 75/0.3 100/0.4 125/0.5 150/0.6 200/0.8 250/1.0
0/0 25/0.1 37/0.15 50/0.2 75/0.3 100/0.4 125/0.5 150/0.6 200/0.8 250/1.0

Air volume (CFM)
598 613 625 630 632 635 631 624 614 624 692 690 685 695 693 692 688 684 670 654 752 746 750 756 750 746 741 745 735 714

36K

Fan speed
Low
Mid
High

Static pressure (Pa/in WC)
0/0

Air volume (CFM)
879

25/0.1 883

37/0.15 888

50/0.2 892

75/0.3 893

100/0.4 893

125/0.5 892

150/0.6 890

200/0.8 873

250/1.0 826

0/0 1010

25/0.1 1001

37/0.15 1001

50/0.2 1000

75/0.3 995

100/0.4 995

125/0.5 996

150/0.6 983

200/0.8 996

250/1.0 969

0/0 1137

25/0.1 1123

37/0.15 1119

50/0.2 1120

75/0.3 1112

100/0.4 1111

125/0.5 1113

150/0.6 1101

200/0.8 1094

250/1.0 1088

48K

Fan speed
Low
Mid
High

Static pressure (Pa/in WC)
0/0 25/0.1 37/0.15 50/0.2 75/0.3 100/0.4 125/0.5 150/0.6 200/0.8 250/1.0
0/0 25/0.1 37/0.15 50/0.2 75/0.3 100/0.4 125/0.5 150/0.6 200/0.8 250/1.0
0/0 25/0.1 37/0.15 50/0.2 75/0.3 100/0.4 125/0.5 150/0.6 200/0.8 250/1.0

Air volume (CFM)
946 943 942 948 947 940 940 933 925 925 1155 1156 1154 1154 1143 1147 1149 1143 1140 1113 1325 1328 1337 1337 1330 1333 1338 1335 1321 1321

Fan speed
Low
Mid
High

60K
Static pressure (Pa/in WC)
0/0 25/0.1 37/0.15 50/0.2 75/0.3 100/0.4 125/0.5 150/0.6 200/0.8 250/1.0
0/0 25/0.1 37/0.15 50/0.2 75/0.3 100/0.4 125/0.5 150/0.6 200/0.8 250/1.0
0/0 25/0.1 37/0.15 50/0.2 75/0.3 100/0.4 125/0.5 150/0.6 200/0.8 250/1.0

Air volume (CFM)
1151 1133 1136 1132 1128 1134 1130 1133 1126 1118 1367 1358 1362 1361 1360 1352 1353 1348 1340 1316 1608 1590 1586 1560 1561 1554 1549 1545 1543 1548

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Page 46

Air Evacuation & Adding Refrigerant

8

Preparations and Precautions
If air or foreign matter is present within the refrigerant system, it can cause abnormal rises in pressure, which can reduce its efficiency, damage the unit, and/or cause personal injury. Use a vacuum pump and manifold gauge to evacuate the refrigerant system to remove any non-condensable gas and moisture from the system. This process should be performed upon initial installation and when refrigerant is removed for any reason.
BEFORE PERFORMING EVACUATION
· Ensure the refrigerant piping between the indoor and outdoor units are connected properly.
· Ensure all wiring and electrical connections are properly connected.

Evacuation Instructions

1. Connect the charge hose of the manifold gauge to the service port on the outdoor unit low pressure valve.

2. Connect another charge hose from the manifold gauge to the vacuum pump.

3. Open the low pressure side of the manifold gauge. Keep the high pressure side closed.

4. Turn on the vacuum pump to evacuate the system.

5. Run the vacuum for at least 15 minutes, or until the Micron gauge reads 500 micron.

Manifold Gauge

Compound gauge 500 Micron

Pressure gauge

Low pressure valve Pressure hose/ Charge Hose

High pressure Charge hose
Vacuum Pump

Low pressure valve
6. Close the low pressure side of the manifold gauge and turn off the vacuum pump.
7. Wait 5 minutes, then check that there has not been any change in system pressure.

8. If there is a significant change in system pressure, check for leaks. If there is no change in system pressure, unscrew the cap from the high pressure valve. · If pressure rises but becomes stable below 1000 Microns, it is okay to open the valves. · If the pressure becomes stable above 1000 but below 2000 Microns there is moisture in the system. Further evaluation and dehydration is required. · If pressure rises above 2000 Microns or does not become stable, indicates there is a leak.
9. Then, insert an Allen/hexagonal wrench into the high pressure valve. Open the valve by turning the wrench counterclockwise 1/4 of a turn. Listen for gas to exit the system, then close the valve after 5 seconds.
10. Watch the pressure gauge for 1 minute to ensure that there is no change in pressure. The pressure gauge should read slightly higher than atmospheric pressure.
11. Remove the charge hose from the service port.
Flare nut
Cap
valve body valve stem
12. Using an Allen/hexagonal wrench, fully open both the high pressure and low pressure valves.
OPEN VALVES GENTLY · When opening the valves, continue turning the Allen/hexagonal wrench gently until it reaches the stopper. DO NOT try to force the valve to open further than this. · Ensure the Allen/hexagonal wrench is inserted fully into valve stem socket. Failure to do this, or using a stepped service valve tool could result in stripping the valve stem socket. 13. Tighten the valve caps on all three valves
(service port, high pressure, & low pressure) by hand. You may need to tighten them further using a wrench or torque wrench if necessary.

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mrcool.com

Air Evacuation & Adding Refrigerant

Note on Adding Refrigerant
Some systems require additional refrigerant charging depending on pipe lengths. The standard pipe length varies according to local regulations. For example, in North America, the standard pipe length is 25 ft (7.5 m). In other areas, the standard pipe length is 16 ft (5 m). The system MUST be operating in cooling mode to add refrigerant. The refrigerant should be charged as liquid from the service port on the outdoor unit’s low pressure valve. The additional refrigerant to be charged can be calculated using the following formula:
Liquid Side Pipe Diameter

1/4 in (6.35 mm) 3/8 in (9.52 mm) 1/2 in (12.7 mm)

R410A: (Metering device in
the indoor unit):

(Total pipe length –

(Total pipe length – (Total pipe length –

standard pipe length) standard pipe length) standard pipe length)

x 30g (0.32oZ)/m(ft) x 65g (0.69oZ)/m(ft) x 115g (1.23oZ)/m(ft)

R410A: (Metering device in the outdoor unit):

(Total pipe length – (Total pipe length – (Total pipe length standard pipe length) standard pipe length) standard pipe length) x 15g (0.16oZ)/m(ft) x 30g (0.32oZ)/m(ft) x 65g (0.69oZ)/m(ft)

CAUTION
DO NOT mix refrigerant types.

Refrigerant Type, Charge, & Design Pressure

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Page 48

Care & Maintenance

9

Cleaning the Indoor Unit
BEFORE CLEANING OR PERFORMING MAINTENANCE
Always turn off the system and disconnect its power supply before cleaning or performing any
.type of maintenance. Contact an authorized service technician for repair or maintenance. Improper repair and maintenance may cause water leakage, electrical shock, and/or fire. It could also void your warranty. . Ensure the drain hose is set up according to the instructions. Failure to do this could result in leakage that could cause personal property damage, fire, and/or electric shock. . Make sure that all wires are connected securely and properly. Failure to connect wires according to the instructions could result in property damage, electrical shock, and/or fire. DO NOT substitute a blown fuse with a higher or lower amperage fuse, as this could cause damage to the circuit and/or an electrical fire.
CAUTION
Only use a soft, dry cloth to wipe the unit clean. If the unit is especially dirty, you can use a warm, damp cloth to wipe it clean.
DO NOT use chemicals or chemically treated cloths to clean the unit. DO NOT use benzene, paint thinner, polishing powder, or other solvents to clean the unit. They can cause the plastic surface to crack or deform. DO NOT use water hotter than 104°F (40°C) to clean the front panel. This can cause the panel to deform or become discolored. DO NOT wash the unit under running water, as this could create an electrical hazard.
Air Filter Replacement
The air filter prevents dust and other particles from entering the indoor unit. Dust can accumulate and reduce the efficiency of the unit. For optimum efficiency, clean the air filter every two weeks, or more frequently if you live in a dusty area. If the filter is heavily clogged and cannot be cleaned, replace the filter with a new one.
CAUTION
· Before changing the filter or cleaning, turn off the unit and disconnect the power supply. · When removing the filter, do not touch the metal parts of the unit. The sharp metal edges can
cause injury. · Any maintenance or cleaning of the outdoor unit should be performed by an authorized dealer
or a licensed service provider. · Any unit repairs should be performed by an authorized dealer or a licensed service provider.
DO NOT use water to clean the inside of the indoor unit. Doing this could destroy the insulation and could cause electrical shock. DO NOT expose the filter to direct sunlight when drying, as this could cause it to shrink.
NOTE ON AIR FILTER REPLACEMENT
Replace the air filter every 30 to 90 days depending on the Minimum Efficiency Reporting Values (MERVs) Rating.

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mrcool.com

Care & Maintenance

1. Remove cover plate.
2. Slide out the air filter.
3. Clean the air filter by vacuuming the surface or washing it in warm water with mild detergent.
4. If using water, allow the filter to dry.
5. Reinstall the filter by reversing steps 1 & 2.
NOTE: · In households with animals, the grille will
periodically need to be wiped down to prevent animal hair from blocking airflow. · If the unit has a filter installed from the factory, it is only there for an energy efficiency sampling test. The user will need to use a filter that meets the requirements of UL900.

Aiccroofivvelertrer Air filter

If using water, the inlet side should face down and away from the water stream.

If using a vacuum cleaner, the inlet side should face the vacuum.

Maintenance – Preparation for Extended Periods of Non-Use If you plan on not using the unit for an extended period of time, please do the following:

Replace all filters

Turn on the FAN until the

Turn off the unit and

unit is completely dried out disconnect the power

Maintenance – Pre-Season Inspection

After extended periods of non-use, or in preparation for periods of frequent use, please do the following:

Check for damaged wires Replace all filters

Check for leaks

Make sure nothing is blocking the air inlets and outlets mrcool.com

Page 50

Refrigerant Piping Connection
Electrical and Gas Leak Checks

180

WARNING ­ RISK OF ELECTRICAL SHOCK
ALL WIRING MUST BE INSTALLED BY A LICENSED ELECTRICIAN AND COMPLY WITH LOCAL, STATE, AND NATIONAL ELECTRICAL CODES.
Electrical Safety Checks
After installation is complete, confirm that all electrical wiring has been installed in accordance with local and national regulations, and according to the installation manual.
BEFORE TEST RUN
Check Insulated Resistance The insulated resistance must be more than 2M.
Check Grounding Work Measure grounding resistance by visual detection and with a grounding resistance tester. Grounding resistance must be less than 0.1.
NOTE: This may not be required for some locations in North America.
DURING TEST RUN
Check for Electrical Leakage
During the Test Run, use an electroprobe and multimeter to perform a comprehensive electrical leakage test.
IF ELECTRICAL LEAKAGE IS DETECTED
If electrical leakage is detected, turn off the unit immediately and call a licensed electrician to find and resolve the cause of the leakage.
NOTE: This may not be required for some locations in North America.

Gas Leak Checks
There are two different methods to check for gaseous leaks. Use Fig. 10.1 below as a guide for the critical points to check for leaks.
Soap and Water Method
Using a soft brush or spray bottle, apply a soapy water solution to all of the pipe connection points of the indoor and outdoor units, watching to see if any bubbles form. The presence of bubbles indicates there is a leak.

Leak Detector Method If using a leak detector, refer to the device’s operation/instruction manual for proper usage instructions.
AFTER PERFORMING GAS LEAK CHECKS
After confirming that all of the refrigerant pipe connection points DO NOT leak, replace the valve cover on the outside unit and wrap and insulate the piping connections.

Check-point of indoor unit

Check-point of outdoor unit
D

B

C

A

A: Low pressure stop valve B: High pressure stop valve C & D: Indoor unit flare nuts
Fig. 10.1
NOTE: Fig. 10.1 above is for demonstration purposes only. It represents the connection points to check for leaks.

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mrcool.com

Refrigerant Piping Connection
Test Run

11

Before Test Run
A test run must be performed after the entire system has been completely installed. Complete and confirm the list of checks below before performing a test run.
List of Checks to Perform Before Test Run
· The indoor & outdoor units are properly installed
· Unit is properly grounded · All wiring & electrical terminals are properly
covered & connected · The power voltage is the correct voltage for
the unit · Length of piping and additional refrigerant
stow capacity have been recorded. · All refrigerant piping connection points are
properly connected and DO NOT leak · Water drains properly from drain pipe and to
a safe location · Heating insulation is properly installed · Ensure there are no obstacles near the inlet
and outlet of the outdoor or indoor units · Ensure all connection valves on the outdoor
condenser are fully opened
Test Run Instructions
Failure to perform the test run could result in damage to the unit, property, or personal injury. Only perform test run after you have ensured the following steps have been completed: · Electrical Safety Checks – Confirm that the
unit’s electrical system is safe and operating properly. · Gas Leak Checks – Check all refrigerant piping/line set connections and confirm that the system is not leaking. · Confirm that the gas and liquid (high and low pressure) stop valves are fully open.

You should perform the Test Run for at least 30 minutes.
1. Connect power to the unit. Then, turn on the main power switch and allow the unit to warm up.
2. Set the air conditioner to COOL mode.
List of Checks to Perform During Test Run
For Indoor Unit
· Ensure the room temperature is being registered/displayed correctly
· Ensure the manual buttons of the indoor air handler function properly
· Check to see that the drainage system is unimpeded and draining smoothly
· Ensure there is no vibration or abnormal noise during operation
For Outdoor Unit
· Ensure refrigerant system & piping connections DO NOT leak
· Ensure there is no vibration or abnormal noise during operation
· Ensure the wind, noise, and water generated by the unit DO NOT pose a safety hazard or cause a disruption to your neighbors
Drainage System Test This test is to ensure the drainage system is functioning properly and drains smoothly. New buildings should have this test performed before the ceiling is finished.
1. Remove the test cover. Then, add 2,000 ml of water to the tank through the attached tube.
2. Turn on the main power switch and run the air conditioner in COOL mode.
3. Listen to the sound of the drain pump to see if it makes any unusual noises.
4. Ensure that the water is being discharged. It may take up to one minute before the unit begins to drain depending on the drain pipe.
5. Ensure that there are no leaks in any of the piping.
6. Then, stop the air conditioner. Turn off the main power switch and reinstall the test cover.
NOTE: If the unit malfunctions or does not operate correctly, please refer to the Troubleshooting section of this manual before contacting technical support.

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Troubleshooting

12

Common Issues The following events may occur during normal operation, and may not indicate a malfunction or a need for repairs.

Symptom
Unit does not turn on when pressing ON/OFF button.
The unit changes from COOL/HEAT mode to FAN mode.

Cause
The unit has a 3 minute protection feature that prevents the unit from overloading. The unit cannot be restarted within 3 minutes of being turned off.
Cooling & Heating models: If the operation light and PRE-DEF (pre-heating/ Defrost) indicators are illuminated, the outdoor temperature is too cold and the unit’s anti-cold wind is activated in order to defrost the unit.
In Cooling-Only models: If the FAN-ONLY indicator is illuminated, the outdoor temperature is too cold and the unit’s antifreeze protection is activated in order to defrost the unit.
The unit may change its setting to prevent frost from forming on the unit. Once the temperature increases, the unit will start operating in the previously selected mode again.
Once the set temperature has been reached, at this point the unit turns off the compressor. The unit will continue operating when the temperature fluctuates again.

A low hissing sound during operation: This is normal and is caused by refrigerant gas flowing through both indoor and outdoor units.

Indoor unit and outdoor unit make noises.

A low hissing sound when the system starts, has just stopped running, or is defrosting: This noise is normal and is caused by the refrigerant gas changing direction or stopping.

Normal expansion and contraction of the plastic and metal parts caused by temperature changes during operation can cause squeaking noises.

The outdoor unit makes noises.
The unit emits a bad odor.
Outdoor unit fan does not operate.

The unit will make different noises based on which mode it is currently operating in. The unit may absorb odors from the environment (such as furniture, cooking, cigarettes, etc.) which will be emitted during operations. The unit’s filters have become moldy and should be cleaned.
During operation, the fan speed is controlled to optimize product operation.

Dust is emitted from The unit may accumulate dust during extended periods of non-use, which will be

the indoor or

emitted when the unit is turned on. This can be mitigated by covering the unit

outdoor unit.

during extended periods of not being used.

The compressor continues to run, and During defrosting mode, the compressor continues to run, the indoor and

the indoor and

outdoor motors will cease operation, the defrost light on the indoor unit will turn

outdoor motors

on, and the

symbol is displayed.

aren’t operational.

NOTE: If problem persists, contact a local dealer or your nearest customer service center. Provide them with a detailed description of the unit malfunction as well as the model number of your unit.

For detailed error code list, refer to the Service Manual.

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mrcool.com

WARNING

In the case of any of the following, turn off the unit immediately!
· Signal/power cable is damaged or abnormally warm · Burning odor · Loud or abnormal sounds · A power fuse or circuit breaker trips frequently · Water or other objects fall into or out of the unit

DO NOT ATTEMPT TO CORRECT OR FIX THESE ITEMS YOURSELF!
CONTACT AN AUTHORIZED SERVICE PROVIDER IMMEDIATELY!

Before calling for service assistance, troubleshoot a problem by performing the following checks:

Symptom

Possible Causes

Solution

Poor Cooling Performance

Temperature setting may be higher than Lower the temperature setting. ambient room temperature.

The air filter is dirty.

Remove the filter and clean it according to the instructions.

The air inlet or outlet of either unit is blocked. Doors and windows are open.

Turn the unit off, remove the obstruction and turn it back on. Ensure all windows and doors are closed while operating the unit.

Excessive heat is generated by sunlight. Close windows and curtains during

periods of high heat or bright

sunshine.

Too many other sources of heat in the

Reduce the amount of heat sources.

room (people, computers, electronics, etc.).

Low refrigerant due to a leak or long-term Check for leaks, reseal if necessary,

use.

and top off the refrigerant level.

The heat exchanger on the indoor or outdoor unit is dirty.

Clean the affected heat exchanger.

Non-Working Unit

Power failure.

Wait for power to be restored.

The power is turned off.

Turn on the power.

The fuse is burned out.

Replace the fuse.

Remote control batteries are dead.

Replace the batteries.

The unit’s 3 minute protection feature has Wait three minutes after restarting

been activated.

the unit.

Timer is activated.

Turn timer off.

System circuit is blocked.

Determine the location of the

blockage and repair.

Frequent Stopping &
Starting

There’s too much or too little refrigerant in the system.
Incompressible gas or moisture has entered the system.

Check for leaks and recharge the system with refrigerant.
Evacuate and recharge the system with refrigerant.

The compressor is broken.

Replace the compressor.

The voltage is too high or too low.

Install a manostat to regulate the voltage.

Poor Heating Performance

The outdoor temperature is extremely low. Use auxiliary heating device.

Cold air is entering through doors and windows.

Make sure that all doors and windows are closed during use.

Low refrigerant due to leak or long-term Check for leaks, re-seal if necessary,

use.

and top off refrigerant.

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Page 54

Refrigerant Piping Connection

EU Disposal Guidelines

13

The marking shown below when depicted on the product or its literature, indicates that electrical waste and electrical equipment should not be mixed with general household waste.

Correct Disposal of This Product (Electrical Waste & Electronic Equipment)
This appliance contains refrigerant and other potentially hazardous materials. When disposing of this appliance, the law requires special collection and treatment.
DO NOT dispose of this product as household waste or unsorted municipal waste.
When disposing of this appliance, you have the following options:
· Dispose of the appliance at a designated municipal electronic waste collection facility. · When buying a new appliance, the retailer will receive the old appliance free of charge. · The manufacturer will receive the old appliance free of charge. · Sell the appliance to certified scrap metal dealers.
Special Notice Disposing of this appliance in the forest or other natural surroundings endangers your health and is bad for the environment. Hazardous substances may leak into the ground water and enter the food chain.

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mrcool.com

Hyper-Heat Single-Zone 24K-60K Ducted Air Handler
Due to updates and constantly improving performance, the information and instructions within this manual are subject to change without notice. Please visit www.mrcool.com/documentation to ensure you have the latest version of this manual.

References

• MRCOOL – Comfort Made Simple
• MRCOOL Patents – MRCOOL

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