Mrcool CASSETTE18HP230CPO Olympus Ceiling Cassette Indoor User Manual

MODELS:

Read this manual carefully before installation and keep it where

the operator can easily nd it for future reference.

Due to updates and constantly improving performance, the

information and instructions within this manual are subject to

change without notice.

Version Date: May 12, 2025

Please visit www.mrcool.com/documentation

to ensure you have the latest version of this manual.

CASSETTE*HP-230C-O

This product utilizes R-454B refrigerant

Olympus Series

Cassette

Air Handler

Service Manual

mrcool.com1

CONTENTS

SAFETY ............................................................................................................................... 2

SYSTEM OVERVIEW ........................................................................................................... 9

2.1 Model Reference .................................................................................................. 9

2.2 External Appearance ........................................................................................... 9

2.3 Dimensional Drawings ...................................................................................... 10

2.4 Part Names ......................................................................................................... 12

2.5 Service Place ...................................................................................................... 12

2.6 Air Velocity & Temperature Distributions ...................................................... 13

2.7 Sound Pressure Levels & Curves ..................................................................... 21

2.8 Refrigerant System Diagram ............................................................................ 22

2.9 Electrical ............................................................................................................. 22

INSTALLATION ................................................................................................................ 32

3.1 Location .............................................................................................................. 32

3.2 Indoor Unit Installation .................................................................................... 32

3.3 Panel Installation ............................................................................................... 34

3.4 Drain Pipe Installation ...................................................................................... 35

3.5 Refrigerant Pipe Installation ............................................................................ 36

3.6 Insulation ............................................................................................................ 37

3.7 Electrical Wiring ................................................................................................. 38

PRODUCT FEATURES ...................................................................................................... 39

4.1 Display Function ................................................................................................ 39

4.2 Safety Features .................................................................................................. 39

4.3 Basic Functions .................................................................................................. 40

TROUBLESHOOTING ...................................................................................................... 44

5.1 Safety Caution .................................................................................................... 44

5.2 Error Display (Indoor Unit) ............................................................................... 45

5.3 Information Inquiry & Setting .......................................................................... 46

5.4 Error Diagnosis Without Error Code ................................................................ 47

5.5 Quick Maintenance by Error Code .................................................................. 58

5.6 Troubleshooting by Error Code ....................................................................... 60

5.7 Check Procedures .............................................................................................. 80

TEMPERATURE SENSOR RESISTANCE TABLE ............................................................... 81

SYSTEM PRESSURE TABLE .............................................................................................. 83

Contents

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SAFETY

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.

Safety Precautions

CAUTION

Indicates the possibility of personal injury or loss of life.

Indicates the possibility of property damage or serious

consequences.

Read Before Using

WARNING

WARNING FOR PRODUCT INSTALLATION

INSTALLATION MUST BE PERFORMED BY AN AUTHORIZED DEALER OR SPECIALIST. DEFECTIVE

INSTALLATION CAN CAUSE WATER LEAKAGE, ELECTRICAL SHOCK, OR FIRE.

****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re.

DO NOT turn on the power until the installation and all work has been completed.

1. Installation must be performed according to the installation instructions. Improper installation could cause

water leakage, electrical shock, or re.

2. Contact an authorized service technician for repair or maintenance of this unit.

3. This appliance must be installed in accordance with national wiring regulations.

4. Only use the included accessories, parts, and specied parts for installation. Using non-standard parts can

cause water leakage, electrical shock, re, and/or failure of the unit.

5. Install the unit in a rm 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.

6. Install the drainage piping according to the instructions in this manual. Improper drainage could cause

water damage to your home and/or property.

7. When moving or relocating the air conditioner, consult experienced service technicians for disconnection

and re-installation of the unit.

8. 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.

9. USB device access, replacement, and maintenance operations must be carried out by professional sta.

WARNING FOR CLEANING & MAINTENANCE

1. DO NOT clean the unit with excessive amounts of water.

2. DO NOT clean the unit with combustible cleaning agents, as these could cause deformation and/or re.

3. Turn o the device and disconnect the power before cleaning. Failure to do this could result in electrical

shock.

TAKE NOTE OF FUSE SPECIFICATIONS

• The unit’s circuit board (PCB) is designed with a fuse to provide over-current protection.

• The specications of the fuse are printed on the circuit board, examples of such are T5A/250VAC and

T10A/250VAC.

Note: Only a blast-proof ceramic fuse can be used.

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SAFETY

WARNING FOR PRODUCT USE

DO NOT insertngers,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ammablesprayssuchashairspray,lacquerorpaintneartheunit,asthiscould

 causere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directcoolairowfromtheunitforaprolongedperiod

of time.

1. If the unit operates abnormally (emits strange noises or a burning smell), immediately turn o the unit

and disconnect the power in order to avoid electric shock, re, 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 deciency.

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 is not intended for use by persons(including children) with reduced physical, sensory or

mental capabilities, or lack of experience and knowledge, unless they have been given supervision or

instruction concerning use of the appliance by a person responsible for their safety. Children should be

supervised to ensure that they do not play with the appliance.

5. Turn o the unit and disconnect the power before performing any cleaning, installation, or repairing.

Failure to do so can cause electric shock.

ELECTRICAL WARNINGS

****ELECTRICAL WORK MUST BE COMPLETED BY A QUALIFIED ELECTRICAL TECHNICIAN****

DO NOT sharethepowersupplywithotherappliances.Animproperorinsucientpower

 supplycouldcausereand/orelectricalshock.

1. Only use the specied wire. If the wire is damaged, it must be replaced by the manufacturer, its service

agent or similarly qualied persons in order to avoid a hazard.

2. The product must be properly grounded during installation or electrical shock could occur.

3. Appropriate wiring standards, regulations, and the installation manual must be followed for all electrical

work.

4. If connecting power to xed wiring, an all-pole disconnection device must be incorporated in the xed

wiring in accordance with the wiring rules and must meet the following requirements: at least 3 mm of

clearances in all poles, a leakage current that may exceed 10 mA, and a residual current device (RCD)

having a rated residual operating current not exceeding 30 mA.

5. Connect cables tightly and clamp them securely to prevent external forces from damaging the terminal.

CAUTION

DO NOT allow the air conditioner to operate for extended periods of time with the doors or

windows open, or in very high humidity.

DO NOT operate the air conditioner 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 o the unit and disconnect the power if the unit will not be used for an extended period of time.

3. Turn o and unplug the unit during storms.

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SAFETY

FLAMMABLE REFRIGERANT WARNINGS

1. The installation of pipe-work should be kept to a minimum and should be protected from physical damage.

2. Refrigerant pipes should comply with national gas regulations.

3. All mechanical connections and ventilation openings should be kept clear of obstruction.

4. Utilize proper disposal processes based on national regulations.

5. Any person involved with working on or breaking into a refrigerant circuit should hold a current valid

certicate from an industry-accredited assessment authority, which authorizes their competence to handle

refrigerants safely in accordance with an industry recognized assessment specication.

6. Maintenance and repair requiring the assistance of other skilled personnel shall be carried out under the

supervision of the person competent in the use of ammable refrigerants.

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

the manufacturer.

8. The appliance shall be stored in a room without continuously operating ignition sources (for example: open

ames, an operating gas appliance, or an operating electric heater).

9. Do not allow foreign matter (oil, water, etc.) to enter the piping, and securely seal the opening by pinching,

taping, etc.

10. Do not pierce or burn.

11. Refrigerants may not contain an odor.

12. Working procedures that aect safety should only be carried out by competent persons.

13. The unit should be stored in a well-ventilated area where the room size corresponds to the room area as

specic for operation, and should be stored so as to prevent potential mechanical damage from occurring.

14. Joints should be tested with detection equipment with a capability of 5 g/year of refrigerant or better, with

the equipment in standstill and under operation or under a pressure of at least these standstill or operation

conditions after installation. Detachable joints should NOT be used in the indoor side of the unit (brazed,

welded joint could be used).

15. A leak detection system is installed. The unit must be powered except for service. For units with a refrigerant

sensor, the indoor unit will display an error code and emit a buzzing sound, the compressor of the outdoor

unit will immediately stop, and the indoor fan will start running. The service life of the refrigerant sensor

is 15 years. When the refrigerant sensor malfunctions, the indoor unit will display the error code "FHCC".

The refrigerant sensor cannot be repaired and can only be replaced by the manufacturer. It should only be

replaced with the sensor specied by the manufacturer.

16. When a ammable refrigerant is used, the requirements for installation space of the appliance and/or

ventilation requirements are determined according to:

• The mass charge amount (M) used in the unit.

• The installation location.

• The type of ventilation of the location of the unit.

• Piping material, pipe routing, and installation must include protection from physical damage in

operation and service. This must be in compliance with local codes and standards, such as ASHRAE

15, IAPMO Uniform Mechanical Code, ICC International Mechanical Code, or CSA B52. All eld joints

must be accessible for inspection prior to being covered or enclosed.

• Protection devices, piping and ttings must be protected as much as possible against adverse

environmental eects. For example, against the danger of water collecting and freezing in relief pipes

or against accumulation of dirt or debris.

ELECTRICAL WARNINGS

Improper electrical connections could overheat, causing re 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 re, or cause electrical shock.

7. Disconnection must be incorporated in the xed wiring in accordance with the wiring rules.

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SAFETY

FLAMMABLE REFRIGERANT WARNINGS

• Piping in refrigeration systems must be designed and installed to minimize the likelihood of hydraulic

shock, resulting in damage from the system.

• Steel pipes and components must be protected against corrosion with a rust-proof coating before

applying insulation.

• Precautions must be taken against excessive vibration or movement of the unit.

• The minimum oor area of the room must be mentioned in the form of a table or a single gure

without reference to a formula.

17. After completion of eld piping for split systems, the eld pipework should be pressure tested with an inert

gas and then vacuum tested prior to refrigerant charging, according to the following requirements:

• The minimum test pressure for the low side of the system should be the low side design pressure and

the minimum test pressure for the high side of the system should be the high side design pressure,

unless the high side of the system cannot be isolated from the low side of the system in which case the

entire system should not be pressure tested to the low side design pressure.

• The test pressure after removal of pressure source shall be maintained for at least 1 hour with no

decrease of pressure indicated by the test gauge, with test gauge resolution not exceeding 5% of the

test pressure.

18. Prior to beginning work on systems containing ammable refrigerants, safety checks are necessary

to ensure that the risk of ignition is minimized. For repairs to the refrigerating system, the following

precautions shall be complied with prior to conducting work on the system.

19. Work should be undertaken under a controlled procedure so as to minimize the risk of a ammable gas or

vapor being present while the work is being performed.

20. All maintenance sta and others working in the local area should be instructed on the nature of work being

carried out. Avoid work in conned spaces.

21. The area should be checked with an appropriate refrigerant detector prior to and during work, to ensure the

technician is aware of potentially ammable atmospheres. Ensure that the leak detection equipment being

used is suitable for use with ammable refrigerants, i.e. no sparking, adequately sealed, or intrinsically safe.

22. If any hot work is to be conducted on the refrigeration equipment or any associated parts, appropriate re

extinguishing equipment should be on site and readily available. Have a dry power or CO2 re extinguisher

adjacent to the charging area.

23. No person carrying out work in relation to a refrigerating system which involves exposing any pipe work

should use any sources of ignition in such a manner that it may lead to the risk of re or explosion. All

possible ignition sources, including cigarette smoking, should be kept suciently far away from the site

of installation, repairing, removing, and disposal, during which refrigerant can possibly be released to the

surrounding space. Prior to work taking place, the area around the equipment is to be surveyed to make

sure that there are no ammable hazards or ignition risks. "No Smoking" signs should be displayed.

24. Ensure that the area is in the open or that it is adequately ventilated before breaking into the system or

conducting any hot work. A degree of ventilation shall continue during the period that the work is carried

out. The ventilation should safely disperse any released refrigerant and preferably expel it externally into the

atmosphere.

23. Where electrical components are being changed, they shall be t for the purpose and to the correct

specication. At all times the manufacturer's maintenance ad service guidelines shall be followed. If in

doubt, consult the manufacturer's technical department for assistance. The following checks should be

applied to installations using ammable refrigerants:

• the actual refrigerant charge is in accordance with the room size within which the refrigerant containing

parts are installed;

• the ventilation machinery and outlets are operating adequately and are not obstructed;

• if an indirect refrigerating circuit is being used, the secondary circuits should be checked for the

presence of refrigerant;

• marking to the equipment continues to be visible and legible, marking and signs that are illegible

should be corrected;

• refrigerant pipe or components are installed in a position where they are unlikely to be exposed to

any substance which may corrode refrigerant containing components, unless the components are

constructed of materials which are inherently resistant to or protected against corrosion.

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SAFETY

FLAMMABLE REFRIGERANT WARNINGS

24. Repair and maintenance to electrical components shall include initial safety checks and component

inspection procedures. If a fault exists that could compromise safety, then no electrical supply shall be

connected to the circuit until it is satisfactorily dealt with. If the fault cannot be corrected immediately but it

is necessary to continue operation, an adequate temporary solution should be used.

25. Initial safety checks should include:

• that capacitors are discharged: this should be done in a safe manner to avoid the possibility of sparking;

• that there are no live electrical components and wiring are exposed while charging, recovering, or

purging the system;

• that there is continuity of earth bonding.

26. Sealed electrical components should be replaced if damaged.

27. Intrinsically safe components should be replaced if damaged.

28. Check that wiring will not be subject to wear, corrosion, excessive pressure, vibration, sharp edges, or

any other adverse environmental eects. The check shall also take into account the eects of aging or

continual vibration from sources such as compressors or fans.

29. Under no circumstances should potential sources of ignition be used in the search for or detection of

refrigerant leaks. A halide torch (or any other detector using a naked ame) should not be used. The

following leak detection methods are deemed acceptable for refrigerant systems. Electronic leak detectors

may be used to detect refrigerant leaks but, in the case of ammable refrigerants, the sensitivity may

not be adequate, or may need re-calibration. (Detection equipment shall be calibrated in a refrigerant-

free area.) Ensure that the detector is not a potential source of ignition and is suitable for the refrigerant

used. Leak detection equipment shall be set at a percentage of the LFL of the refrigerant and should

be calibrated to the refrigerant employed, and the appropriate percentage of gas (25% minimum) is

conrmed. Leak detection uids are also suitable for use with most refrigerants but the use of detergents

containing chlorine may react with the refrigerant and corrode the copper work. Examples of leak

detection uids are the bubble method, uorescent method agents, etc. If a leak is suspected, all naked

ames should be removed/extinguished. If a leakage of refrigerant is found which requires brazing, all of

the refrigerant should be recovered from the system, or isolated (by means of shut-o valves) in a part of

the system remote from the leak. See the following instructions of removal of refrigerant.

30. When breaking into the refrigerant circuit to make repairs, or for any other purpose, conventional

procedures should be used. However, for ammable refrigerants, it is even more vital to follow best

practice. The following procedure should be adhered to:

• safely remove refrigerant following local and national regulations;

• evacuate;

• purge the circuit with inert gas;

• evacuate;

• continuously ush or purge with inert gas when using ame to open circuit;

• open the circuit

31. The refrigerant charge should be recovered into the correct recovery cylinders if venting is not allowed by

local and national codes. For units containing ammable refrigerants, the system should be purged with

oxygen-free nitrogen to render the appliance safe for ammable refrigerants. This process might need to

be repeated several times. Compressed air or oxygen shall not be used for purging refrigerant systems.

For appliances containing ammable refrigerants, refrigerant purging should be achieved by breaking the

vacuum in the system with oxygen-free nitrogen and continuing to ll the working pressure is achieved,

then venting to atmosphere, and nally pulling down to a vacuum. This process should be repeated until

no refrigerant is within the system. When the nal oxygen-free nitrogen charge is used, the system should

be vented down to atmospheric pressure to enable work to take place. The outlet for the vacuum pump

should not be close to any potential ignition sources, and ventilation should be available.

32. In addition to conventional charging procedures, the following requirements should be followed:

• Work should be undertaken with appropriate tools only (in case of uncertainty, please consult the

manufacturer of the tools for use with ammable refrigerants)

• Ensure that contamination of dierent refrigerants does not occur when using charging equipment.

Hoses or lines shall be as short as possible to minimize the amount of refrigerant contained in them.

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FLAMMABLE REFRIGERANT WARNINGS

• Ensure that the refrigeration system is grounded prior to charging the system with refrigerant.

• Label the system when charging is complete (if not already).

• Extreme care should be taken not to overll the refrigeration system.

• Prior to recharging the system, it should be pressure tested with oxygen-free nitrogen (OFN). The

system should be leak-tested on completion of charging but prior to commissioning. A follow-up leak

test shall be carried out prior to leaving the site.

33. Before carrying out this procedure, it is essential that the technician is completely familiar with the

equipment and all its detail. It is good recommended practice that all refrigerants are recovered safely.

Prior to the task being carried out, an oil and refrigerant sample should be taken in case analysis is

required prior to re-use of recovered refrigerant. It is essential that electrical power is available before the

task is commenced.

a. Become familiar with the equipment and its operation.

b. Isolate the system electrically.

c. Before attempting the procedure ensure that:

• mechanical handling equipment is available, if required, for handling refrigerant cylinders;

• all personal protective equipment is available and being used correctly;

• the recovery process is supervised at all times by a competent person;

• recovery equipment and cylinders conform to the appropriate standards

Pump down refrigerant system, if possible.

e. If a vacuum is not possible, make a manifold so that refrigerant can be removed from various parts of

the system.

f. Make sure that the cylinder is situated on the scales before recovery takes place.

g. Start the recovery machine and operate in accordance with instructions.

h. Do not overll cylinders (no more than 80% volume liquid charge).

i. Do not exceed the maximum working pressure of the cylinder, even temporarily.

j. When the cylinders have been lled correctly and the process completed, make sure that the cylinders

and equipment are removed from the site promptly and all isolation valves on the equipment are closed o.

k. Recovered refrigerant should not be charged into another refrigeration system unless it has been

cleaned and checked.

34. Equipment shall be labeled stating that it has been decommissioned and emptied of refrigerant. The label

should be dated and signed. For appliances containing ammable refrigerants, ensure that there are labels

on the equipment stating the equipment contains ammable refrigerant.

35. When removing refrigerant from a system, either for servicing or decommissioning, it is good

recommended practice that all refrigerants are removed safely. When transferring refrigerant into

cylinders, ensure that only appropriate refrigerant recovery cylinders are employed. Ensure that the

correct number of cylinders for holding the total system charge is available. All cylinders to be used should

be designated for the recovered refrigerant and labeled for that refrigerant (i.e. special cylinders for the

recovery of refrigerant). Cylinders shall be complete with pressure-relief valve and associated shut-o

valves in good working order. Empty recovery cylinders are evacuated and, if possible, cooled before

recovery occurs. The recovery equipment should be in good working order with a set of instructions

concerning the equipment that is at hand and should be suitable for the recovery of the ammable

refrigerant. If in doubt, the manufacturer should be consulted. In addition, a set of calibrated weighing

scales should be available and in good working order. Hoses should be complete with leak-free disconnect

couplings and in good condition. The recovered refrigerant should be processed according to local

legislation in the correct recovery cylinder, and the relevant waste transfer note arranged. Do not mix

refrigerants in recovery units and especially not in cylinders.

36. If compressors or compressor oils are to be removed, ensure that they have been evacuated to an

acceptable level to make certain that ammable refrigerant does not remain within the lubricant. The

compressor body should not be heated by an open ame or other ignition sources to accelerate this

process. When oil is drained from a system, it should be carried out safely.

37. An unventilated area where the appliance using ammable refrigerants is installed should be constructed

so that should any refrigerant leak, it will not stagnate so as to create a re or explosion hazard. If

appliances connected via an air duct system to one or more rooms below the ventilation requirements,

SAFETY

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FLAMMABLE REFRIGERANT WARNINGS

that room should never contain potential ignition sources. A ame-producing device may be installed

in the space if the device is provided with an eective ame arrest. Auxiliary devices which may be a

potential ignition source should not be installed in the duct work. Examples of such are hot surfaces with

a temperature exceeding 1292°F (700°C) and electric switching devices. Only auxiliary devices (such as

a certied heater kit) approved by the manufacturer or declared suitable with the refrigerant should be

installed in connecting ductwork. False or drop ceilings may be used as a return air plenum if a refrigerant

detection system is provided in the appliance and any external connections are also provided with a sensor

immediately below the return air plenum duct joint. Refrigerant sensors for refrigerant detection systems

should only be replaced with sensors specied by the manufacturer. A leak detection system is installed.

The unit must be powered except for service.

38. Transport of equipment containing ammable refrigerants should comply with transportation regulations.

39. Marking of equipment using signs should comply with local regulations.

40. Disposal of equipment using ammable refrigerants should comply with national regulations.

41. Storage of equipment/appliances should be in accordance with the manufacturer's instructions.

42. Storage of packed (unsold) equipment should be constructed so that mechanical damage to the equipment

inside the package will not cause a leak of the refrigerant charge. The maximum number of pieces of

equipment permitted to be stored together will be determined by local regulations.

43. During the evacuation test, after achieving a vacuum level specied in the manual or less, the refrigeration

system shall be isolated from the vacuum pump and the pressure shall not rise above 1500 microns within

10 minutes. The vacuum pressure level should be specied in the manual, and should be the lessor of 500

microns of the value required for compliance with national and local codes and standards, which may vary

between residential, commercial, and industrial buildings.

• Field-made refrigerant joints indoors should be tightness-tested according to the following

requirements: the test method should have a sensitivity of 5 grams per year of refrigerant or better

under a pressure of at least 0.25 times the maximum allowable pressure. No leak should be detected.

• Any servicing should be performed only as recommended by MRCOOL®.

43. Any maintenance, service, or repair operations must be performed by qualied personnel. Every working

procedure that aects safety should only be carried out by competent persons that are both trained and

certied. The training of these procedures should be carried out by national training organizations or

manufacturers that are accredited to teach the relevant national competency standards that may be set in

legislation. All training should follow the ANNEX HH requirements of UL 60334-2-40 4th Edition.

Examples of such working procedures are:

• breaking into a refrigerant circuit

• opening of sealed components

• opening of ventilated enclosures

Symbols Displayed on Indoor & Outdoor Unit

WARNING

This symbol shows that this appliance uses a ammable refrigerant. If the refrigerant

is leaked and exposed to an external ignition source, there is a risk of re.

CAUTION This symbol shows that the operation manual should be read carefully.

CAUTION

This symbol shows that a service personnel should be handling this equipment with

reference to the installation manual.

CAUTION

This symbol shows that information is available such as the operating manual or

installation manual.

SAFETY

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2.1 Model Reference

Indoor Unit Model Capacity(Btu/h) Power Supply

CASSETTE09HP-230C-O 9K

1Ph, 208/230V~, 60Hz

CASSETTE12HP-230C-O 12K

CASSETTE18HP-230C-O 18K

CASSETTE24HP-230C-O 24K

SYSTEM OVERVIEW

2.2 External Appearance

9/12/18K

24K

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2.3 Dimensional Drawings

9/12/18K

SYSTEM OVERVIEW

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SYSTEM OVERVIEW

24K

Model(KBtu/h) Unit A

mm 205

inch 8.07

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2.4 Part Names

2.5 Service Place

SYSTEM OVERVIEW

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SYSTEM OVERVIEW

2.6 Air Velocity & Temperature Distributions

CASSETTE09-HP230C-O:

Discharge angle 50°

CoolingAirowVelocityDistributions

Cooling Temperature Distributions

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CASSETTE09-HP230C-O:

Discharge angle 65°

HeatingAirowVelocityDistributions

Heating Temperature Distributions

SYSTEM OVERVIEW

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SYSTEM OVERVIEW

CASSETTE12-HP230C-O:

Discharge angle 50°

CoolingAirowVelocityDistributions

Cooling Temperature Distributions

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CASSETTE12-HP230C-O:

Discharge angle 65°

HeatingAirowVelocityDistributions

Heating Temperature Distributions

SYSTEM OVERVIEW

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SYSTEM OVERVIEW

CASSETTE18-HP230C-O:

Discharge angle 50°

CoolingAirowVelocityDistributions

Cooling Temperature Distributions

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CASSETTE12-HP230C-O:

Discharge angle 65°

HeatingAirowVelocityDistributions

Heating Temperature Distributions

SYSTEM OVERVIEW

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SYSTEM OVERVIEW

CASSETTE24-HP230C-O:

Discharge angle 50°

CoolingAirowVelocityDistributions

Cooling Temperature Distributions

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CASSETTE12-HP230C-O:

Discharge angle 65°

HeatingAirowVelocityDistributions

Heating Temperature Distributions

SYSTEM OVERVIEW

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SYSTEM OVERVIEW

2.7 Sound Pressure Levels & Curves

Notes:

• Sound is measured at 4.59ft (1.4m) away from the noisiest location of the unit.

• Data is valid at free eld condition.

• Data is valid at nominal operation condition.

• Reference acoustic pressure OdB=20µPa.

• The sound level will vary depending on a range of factors such as the construction -(acoustic

absorption coecient) of a particular room in which the equipment is installed.

• The operating conditions are assumed to be standard.

CASSETTE09HP-230C-O CASSETTE12HP-230C-O

mrcool.com 22

CASSETTE18HP-230C-O CASSETTE24HP-230C-O

2.8 Refrigerant System Diagram

2.9 Electrical

Indoor Model 9K~24K

Power

Phase 1

Frequency and Volt 208/230V,60Hz

Minimum Circuit Ampacity A 3

Max Fuse A 15

SYSTEM OVERVIEW

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SYSTEM OVERVIEW

IDUCapacity(Btu/h) IDU Wiring Diagram

9~18k 16022500005983

24K 16022500006023

Abbreviation Paraphrase

Y/G Yellow-Green Conductor

PUMP PUMP

TO CCM Comm.Bus Central Controller

T1 Indoor Room Temperature

T2 Coil Temperature of Indoor Heat Exchanger

mrcool.com 24

Indoor Unit Wiring Diagram: 1602250005983

SYSTEM OVERVIEW

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SYSTEM OVERVIEW

Indoor Unit Wiring Diagram: 16022500006023

mrcool.com 26

Connectors:

ForRemoteControl(ON-OFF)TerminalPortCN23andShortConnectorofJR6.

1. Remove the short connector of JR6 when you use ON-OFF function.

2. When the remote switch is o (OPEN); the unit will be o.

3. When the remote switch is on (CLOSED); the unit will be on.

4. When the switch is closed/open the unit will respond to the demand within 2 seconds.

5. When the remote switch is on you can use the remote controller to select the mode desired; when the

remote switch is o the unit will not respond to any demand from the remote.

6. The voltage of the port is 12VDC with a design max current of 5mA.

SYSTEM OVERVIEW

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For ALARM Terminal Port CN33.

1. Provide the terminal port to connect ALARM as the port will not supply power from the unit.

2. Although the design voltage can support higher voltage it is highly advised to have the incoming power less

than 24V with a current draw of less than 0.5A.

3. When the unit occurs a problem the relay will close then the ALARM will activate.

SYSTEM OVERVIEW

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For New Motor Terminal Port CN8.

1. Connect the new fan motor to the port ignoring L/N of the fan motor.

2. The output voltage will be the power supply voltage.

3. The new motor cannot exceed 200W or 1A.

4. The new motor will work when a call is made for the indoor fan to operate.

5. When the unit goes into forced cooling mode or capacity testing mode the new motor will not work.

SYSTEM OVERVIEW

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Micro-Switch:

Anti-Cold Air

SW1 Fan Motor Stop

(Factory Setting)

According to the

EEPROM Setting

Micro-switchSW1isforselectionoftheindoorfanstoptemperature(TEL0)whenitisinanti-

cold wind action in heating mode.

Range:24°C,15°C,8°C,AccordingtotheEEPROMsetting(reserved).

Fan Motor Control Then No Power

Request

SW2/SW2-1 Mode

Fan O

Fan On

(Factory Setting)

Micro-switchSW2/SW2-1isforselectionofindoorFANACTIONifroomtemperaturereachesthe

set point and the compressor stops.

Range: OFF: Anti-cold wind is available in heating mode. ON: No anti-cold wind function.

Note: SW2 dip switch is only reserved as a physical part but without mode modication function, if

changes are needed to the factory setting use the remote control.

Breezeless

SW2-2 Mode

O

(Factory Setting)

Micro-switch SW2-2 is for selection of breezeless function.

Range: OFF, ON.

SYSTEM OVERVIEW

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For Auto-Restart Setting

SW3 Mode

Remember

(Factory Setting)

No Remember

Micro-switch SW3 is for selection of the Auto-Restart Function.

Range: Active, Inactive.

For Temp. Compensation

SW6 Mode

(Factory Setting)

E Function

Micro-switch SW6 is or the selection of temperature compensation in heating mode. This helps

toreducethetemperaturedierencebetweentheceilingandoorsothattheunitcanrun

properly. If the height of installation is lower, a smaller value can be chosen.

Range:6°C,4°C,2°C,EFunction(reservedforspecialcustomizing).

ForHeader/FollowerSetting

SW6 Mode

Header No Follower

(Factory Setting)

Header

Follower

Micro-switchSW8isforsettingMainorSlave(forsomemodels).

Range: No Slave, Main & Slave.

SYSTEM OVERVIEW

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For CCM Unit Address

S2 + S1 Address Dial Address

0~15

(Factory

Setting)

16~31

32~47

48~63

Micro-switch S1 and Dial switch S2 are for address settings when controlling the unit by a

central controller.

Range: 00-63

For Setting Power (DC Motor Model Only

ENC1

Code 0 1 2 3 4 5 6 7 8 9

Power √Auto 6K 9K 12K 16K 18K 20K 22K 24K 30K

Factory

Setting

According To Related Model

Dial switch ENC1: The indoor PCB is universally designed for whole series units from 6K to 30K.

The ECN1 setting will tell the main program what size the unit is.

Range: AUTO, 6K, 9K,...., 30K.

Note: AUTO means the indoor unit is equipped with dierent outdoor units which can automatically

identify the capacity of the outdoor unit, model, single, or multi-zone match up and set the indoor units

parameters.

Usually there is glue on the switch as the switch position cannot be changed at random unless

youusethePCBasasparepartonanotherunit.Ifusingonadierentunityouwillhaveto

select the proper position to match the size of the system.

SYSTEM OVERVIEW

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INSTALLATION

3.1 Location

DO NOT install the unit in the following

locations:

• Coastal areas with high salt content in the air.

• Areas with oil drilling or fracking.

• Areas with caustic gases in the air, such as hot

springs.

• Areas that experience power uctuations, such as

factories.

• Enclosed spaces, such as cabinets.

• Kitchens that use natural gas.

• Areas with strong electromagnetic waves.

• Areas that store ammable materials or gas.

• Rooms with high humidity, such as bathrooms or

laundry rooms.

3.2 Indoor Unit Installation

Capacity(Btu/h) A(inch/mm) H(inch/mm) B(inch/mm)

9/12/18K 9.6/245 >11.4/290 23.6/600

24K 8.07/205 >9.06/230 35.4/900

Hand the Indoor Unit:

1. Use the included paper template to cut a

rectangular hole in the ceiling, leaving at least 39in

(1m) on all sides. The cut hole size should be 16in

(4cm) larger than the body size.

Be sure to mark the areas where ceiling hook

holes will be drilled.

The unit body should align perfectly with the hole,

Be sure that the unit and the hole are the same size

before moving on.

CAUTION

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2. Drill 4 holes 4.7in~6/1in (12cm~15.5cm) deep at

the ceiling hook positions in the internal ceiling. Be

sure to hold the drill at a 90° angle to the ceiling.

3. Using a hammer, insert the ceiling hooks into

the pre-drilled holes. Secure the bolt using the

included washers and nuts.

4. Install the four suspension bolts.

5. Mount the indoor unit. You will need two people

to lift and secure it. Insert suspension bolts into

the unit's hanging holes. Fasten them using the

included washers and nuts.

NOTE: The bottom of the unit should be 0.4~0.98in

(10~25mm) higher than the ceiling board. Generally, L

(indicated in the next gure) should be half the length

of the suspension bolt or long enough to prevent the

nuts from coming o.

Be sure that the unit is completely level. The unit

is equipped with a built-in drain pump and oat

switch. If the unit is tilted against the direction of

condensate ow (the drainpipe is raised), the oat

switch may malfunction and cause water to leak.

CAUTION

When installing the unit in a new home, the ceiling

hooks can be embedded in advance. Make sure

that the hooks do not come loose due to concrete

shrinkage. After installing the indoor unit, fasten

the installation paper template onto the unit with

bolts to determine in advance the dimension

and position of the opening on the ceiling. Follow

the instructions above for the remainder of the

installation.

NOTE FOR NEW HOME INSTALL

INSTALLATION

mrcool.com 34

3.3 Panel Installation

Remove the Front Grille:

1. Push both of the tabs towards the middle

simultaneously to unlock the hook on the grille.

2. Hold the grille at a 45° angle, lift it up slightly and

detach it from the main body.

The panel hook is pre-hung to the indoor unit

owguidering,asshown:

Installthepanelwithfourscrews(M5),as

shown:

(supplied with the panel)

NOTE: If the height of the indoor unit needs to

be adjusted, you can do so through the opening

at the panel's four corners. Make sure that the

internal wiring and drainpipe are not aected by

this adjustment.

Failure to tighten screws can cause water leakage.

CAUTION

If the unit is note hung correctly and a gap exists,

the unit's height must be adjusted to ensure

proper function. The unit's height can be adjusted

by loosening the upper nut and adjusting the

lower nut. Hang the intake grille on the panel, and

then connect the lead connectors of the louver

motor and the control box on the panel to the

corresponding connectors of the main body.

CAUTION

Re-install into the style grid.

Re-install the installation cover.

Fix the installation cover plate rope to the pillar of

the installation cover plate and gently press the

installation cover plate into the panel.

INSTALLATION

mrcool.com35

INSTALLATION

NOTE: After installation, the connector ends of the

display, swing, water pump, and other wire bodies

must be placed in the electric control box.

Connection Diagram:

For panels with out van control module, the display

board CN1 is connected to the main control board

CN10, the motor cable is connected to the main

control board CN14.

For panels with a vane control module, the display

board CN1 is connected to the main control board

CN10, the vane control motor cable is connected to

the main control board CN66.

The display board CN2 is connected to a connecting

cable then connects to the other side of the

connecting cable to an optional wired controller.

3.4 Drain Pipe Installation

Install the drainpipe as illustrated in the following

gure.

NOTE ON DRAINPIPE INSTALLATION:

• When using an extended drainpipe, tighten the

indoor connection with an additional protection

tube to prevent it from pulling loose.

• The drainpipe should slope downward at a

gradient of at least 1/100 to prevent water from

owing back into the air conditioner.

• To prevent the pipe from sagging, space hanging

wires every 39~59in (1~1.5m).

• If the outlet of the drainpipe is higher than the

body's pump joint, provide a lift pipe for the

exhaust outlet of the indoor unit. The lift pipe

must be installed no higher than 29.5in (75cm)

from the ceiling board and the distance between

the unit and the lift pipe must be less than 11.8in

(30cm),

• Incorrect installation could cause water to ow

back into the unit and ood.

• To prevent air bubbles, keep the drain hose level

or slightly tiled up (3in/<75mm).

NOTE: When connecting multiple drainpipes, install

the pipes as illustrated in the following gure.

mrcool.com 36

Pass the drain hose through the wall hole.

Make sure the water drains to a safe location where it

will not cause water damage or a slipping hazard.

NOTE: The drainpipe outlet should be at least 1.9in

(5cm) above the ground. If it touches the ground, the

unit may become blocked and malfunction.

How to install the conduit installation plate (if

supplied).

1. Fix the sheath connector (not supplied) on the wire

hole of the conduit installation plate.

2. Fix the conduit installation plate on the chassis of

the unit.

3.5 Refrigerant Pipe Installation

Pipe Diameter

(inch(mm))

Thickness

(inch/mm)

Ø1/4 (Ø6.35) 0.024/0.6

Ø3/8 (Ø9.52) 0.028/0.7

Ø1/2 (Ø12.7) 0.03/0.75

Ø5/8 (Ø15.9) 0.03/0.75

Ø3/4 (Ø19) 0.031/0.8

Ø7/8 (Ø22) 0.039/1

Recommended Copper Pipe Thickness

Maximum Length and Drop Height:

Be sure that the length of the refrigerant pipe, the

number of bends, and the drop height between the

indoor and outdoor units meet the requirements

shown in the following table.

Capacity(Btu/h)

Max. Length

(ft/m)

Max.

Elevation

(ft/m)

9/12K 82/25 49.2/15

18K 98.4/30 65.6/20

24K 164/50 82/25

CAUTION:

1. The capacity test is based on the standard length

and the maximum permissive length is based on

the system reliability.

2. Oil Traps

• If oil ows back into the outdoor unit's

compressor, this may cause liquid compression or

deterioration of oil return. Oil traps in the rising

gas piping can prevent this.

• An oil trap should be installed every 20ft (6m) of

vertical suction line riser (<36K Btu/h unit).

• An oil trap should be installed every 32.8ft (10m)

of vertical suction line riser (≥36K Btu/h unit).

Procedure of Connecting Pipes:

1. Choose the pipe size according to the specication

table.

2. Conrm the cross way of the pipes.

3. Measure the necessary pipe length.

4. Cut the selected pipe with a pipe cutter.

• Make the section at and smooth.

INSTALLATION

mrcool.com37

5. Insulate the copper pipe.

• Before test operation, the joint parts should not

be heat insulated.

6. Flare the pipe.

• Insert a are nut into the pipe before aring the

pipe.

• According to the following table to are the pipe.

Pipe Diameter

(inch(mm))

Flare Dimension A

Flare Shape

Min. Max.

Ø1/4 (Ø6.35) 0.33/8.4 0.34/8.7

Ø3/8(Ø9.52) 0.52/13.2 0.53/13.5

Ø1/2(Ø12.7) 0.64/16.2 0.65/16.5

Ø5/8(Ø15.9) 0.76/19.2 0.78/19.7

Ø3/4(Ø19) 0.91/23.2 0.93/23.7

Ø7/8(Ø22) 1.04/26.4 1.06/26.9

• After aring the pipe, the opening end must be

sealed to avoid dust or impurities from coming

into the piping.

7. Drill holes if the pipes need to pass through the

wall.

8. If needed bend the pipes slowly to pass through

the wall.

9. Bind and wrap the wire together with the

insulated pipes if necessary.

10. Set the wall conduit.

11. Set the supporter for the pipe.

12. Locate the pipe and x it by the supporter.

• For horizontal refrigerant pipe, the distance

between supporters should not exceed 3.2ft

(1m).

• For vertical refrigerant pipe, the distance

between supports should not exceed 4.9ft

(1.5m).

13. Connect the pipe to the indoor and outdoor unit

by using two crescent wrenches.

• Be sure to use two crescent wrenches and

proper torque to fasten the nut, too much

torque will damage the bell housing, and too

little of torque can cause leakage. Refer to the

following table for dierent pipe connections.

Pipe Diameter

(inch(mm))

Torque

Flare Shape

N.m(lb.ft)

Ø1/4 (Ø6.35) 18~20 (13.3~14.8)

Ø3/8(Ø9.52) 32~39 (23.6~28.8)

Ø1/2(Ø12.7) 49~59 (36.1~43.5)

Ø5/8(Ø15.9) 57~71 (42~52.4)

Ø3/4(Ø19) 67~101 (49.4~74.5)

Ø7/8(Ø22) 85~110 (62.7~81.1)

NOTE: MINIMUM BEND RADIUS

Carefully bend the tubing in the middle according to

the diagram below.

DO NOT bend the tubing more than 90° or more than

3 times.

3.6 Insulation

Insulation of Refrigerant Pipe:

Cut the pipe—insulation (except joint section)—are

the pipe—piping layout and connection—vacuum—

insulate the joining parts

Purpose of Refrigerant Pipe Insulation:

• During operation the temperature of the gas pipe

and liquid pipe will be hot/cold. Therefore, it is

necessary to install insulation; otherwise it will

lower performance or burn up the compressor.

• The gas pipe temperature is low during cooling.

If there is insucient insulation it will condensate

and drip.

• The temperature of the gas pipe is high

(122°F~212°F(50°C~100°C) during heating.

Insulation must be installed to prevent burns.

Insulation Material Selection for Refrigerant Pipe:

• The insulation rating should be over 248°F (120°C).

• Choose insulation according to local codes and

ordnances.

• The thickness of the insulation should be above

0.39in(10mm). If in a hot or wet environment use

thicker insulation.

Humidity<80%RH Humidity≥80%RH

10mm/0.39in 15mm/0.59in

Installation Highlights:

• The gas and liquid pipe should be insulated

separately, if the gas pipe and liquid pipe

were insulated together it will decrease the

performance of the system.

• The insulation material at the joint pipe should be

1.96in~3.93in(5cm~10cm) longer than the gap of

insulation material.

INSTALLATION

mrcool.com 38

• The insulation material at the joint pipe should be

inserted into the gap of the insulation material.

• The insulation material at the joint pipe should be

banded to the gap pipe and liquid pipe tightly.

• The a joining part should be glued together.

• Be sure not to bind the insulating material over-

tight, it may extrude out the air in the material and

cause it to rot.

Insulation of Drainage Pipe:

Operational procedure of refrigerant pipe

insulation.

Select the suitable pipe—insulation (except joint

section)—Piping layout and connection—drainage

test—insulate the joint parts.

Purpose of drainage pipe insulation.

The temperature of the condensate drainage water

is very low. If the insulation is not enough, it shall for

dew and may leak which will cause damage to the

house.

Insulation material selection for drainage pipe.

• The insulation material should be ame retardant

material, the ame retardancy of the material

should be selected according to the local law.

• Thickness of the insulation layer is usually above

10mm/0.39in.

• Use specic glue to past the seam of insulation

material, and then bind with adhesive tape. The

width of tape shall not be less than 5cm/1.97in.

Make sure it is rm and avoid dew.

Installation and highlights of insulation

construction.

• The single pipe should be insulated before

connecting to another pipe, the joint part should

be insulated after the drainage test.

• There should be no insulation gap between the

insulation material.

3.7 Electrical Wiring

• If connecting power to xed wiring, a switch or

circuit breaker that disconnects all poles and has

a contact separation of at least 1/8in(3mm) must

be incorporated in the xed wiring. The qualied

technician must use an approved circuit breaker

or switch.

• Only connect the unit to an individual branch

circuit. Do not connect another appliance to that

outlet.

• Make sure to properly ground the air conditioner.

• Every wire must be rmly connected. Loose wiring

can cause the terminal to overheat, resulting in

product malfunction and possible re.

• Do not let wires touch or rest against refrigerant

tubing, the compressor, or any moving parts

within the unit.

• If the unit has an auxiliary electric heater, it must

be installed at least 40in(1m) away from any

combustible material.

• To avoid electrical shock, never touch the electrical

components after the power supply has been

turned o. After turning o the power, always

wait 10 minutes or more before you touch the

electrical components.

• Make sure that you do not cross your electrical

wiring with your signal wiring as this may cause

distortion, interference, or possibly damage to the

circuit boards.

• No other equipment should be connected to the

same power circuit.

• Connect the outdoor wires before connecting the

indoor wires.

Table: Minimum Cross-Sectional Area of Power

and Signal Cables:

Highlights of Electrical Wiring Installation:

• All wiring must comply with local and national

electrical codes, regulations, and must be installed

by a licensed electrician.

• All electrical connections must be made according

to the Electrical Connection Diagram located on

the panels of the indoor and outdoor unit.

• If there is a serious safety issue with the power

supply, stop work immediately. Explain your

reasoning to the client, and refuse to install the

unit until the safety issue is properly resolved.

• Power voltage should be within 90~110% of the

rated voltage. Insucient power supply can cause

malfunction, electrical shock, or re.

• Installation of an external surge suppressor at the

outdoor disconnect is recommended.

Rated Current of Appliance

(A)

AWG

≤6 18

6~10 16

10~16 14

16~25 12

25~32 10

INSTALLATION

mrcool.com39

4.1 Display Functions

4.2 Safety Features

Compressor three minute delay at restart:

Compressor functions are delayed for up to ten seconds upon the rst startup of the unit, and are

delayed for up to three minutes upon subsequent unit restarts.

Automaticshutobasedondischargetemperature:

If the compressor discharge temperature exceeds a certain level for a period of time, the compressor

ceases operation.

Automaticshutobasedonfanspeed:

If the indoor fan speed registers below 200RPM or over 2100RPM for an extended period of time, the

unit ceases operation and the corresponding error code is displayed on the indoor unit.

Inverter module protection:

The inverter module has an automatic shuto mechanism based on the unit's current, voltage, and

temperature. If the automatic shuto is initiated, the corresponding error code is displayed on the

indoor unit and the unit ceases operation.

Indoor fan delayed operation:

• When the unit starts, the louver is automatically activated and the indoor fan will operate after a

period of setting time or the louver is in place.

• If the unit is in heating mode, the indoor fan is regulated by the anti-cold wind function.

Compressor Preheating:

Preheating is automatically activated when T4 sensor is lower than setting temperature.

Sensorredundancyandautomaticshuto

• If one temperature sensor malfunctions, the air conditioner continues operation and displays the

corresponding error code, allowing for emergency use.

• When more than one temperature sensor is malfunctioning, the air conditioner ceases operation.

PRODUCT FEATURES

mrcool.com 40

PRODUCT FEATURES

4.3 Basic Functions

Abbreviation Element

T1 Indoor room temperature sensor

T2 Evaporator coil temperature sensor

T3 Condenser coil temperature sensor

Outdoor ambient temperature

sensor

Compressor discharge temperature

sensor

Tsc Adjusted setting temperature

CDIFTEMP Cooling shutdown temperature

HDIFTEMP2 Heating shutdown temperature

Unit Element Abbreviations:

In this manual, such as CDIFTEMP, HDIFTEMP2,...etc,

they are well-setting parameter of EEPROM.

Fan Mode:

When fan mode is activated

• The outdoor fan and compressor cease operation.

• Temperature control is disabled and indoor room

temperature is displayed.

• The indoor fan speed can be set to 1%~100%, or

auto.

• The louver operations are identical to those in

cooling mode.

• Auto fan: In fan-only mode, AC operates the same

as auto fan in cooling mode with the temperature

set at 75°F (24°C).

Cooling Mode:

Compressor Control

1. In cooling mode, the indoor fan operates

continuously. The fan speed can be set to

1%~100%, or low, medium, high, and auto.

2. Auto fan action in cooling mode:

• Descent Curve

• When T1-Tsc is lower than 6.3°F/3.5°C, the fan

speed reduces to 80%.

• When T1-Tsc is lower than 1.8°F/1°C, the fan

speed reduces to 60%.

• When T1-Tsc is lower than 0.9°F/0.5°C, the fan

speed reduces to 40%.

• When T1-Tsc is lower than 0°F/0°C, the fan speed

reduces to 20%.

• When T1-Tsc is lower than -0.9°F/-0.5°C, the fan

speed reduces to 1%.

• Rise Curve

• When T1-Tsc is higher than or equal to 0°F/0°C,

the fan speed increases to 20%.

• When T1-Tsc is higher than or equal to

0.9°F/0.5°C, the fan speed increases to 40%.

• When T1-Tsc is higher than or equal to 1.8°F/1°C,

the fan speed increases to 60%.

• When T1-Tsc is higher than or equal to

2.7°F/1.5°C, the fan speed increases to 80%.

• When T1-Tsc is higher than or equal to 7.2°F/4°C,

the fan speed increases to 100%.

Condenser Temperature Protection

When the condenser temperature exceeds a

congured value, the compressor ceases operation.

Evaporator Temperature Protection

• O: Compressor Stops.

• Decrease: Decreases the running frequency to the

lower level per 1 minute.

• Hold: Keep the current frequency.

• Resume: No limitation for frequency.

HEATING MODE:

Indoor Fan Control

1. In heating mode, the indoor fan operates

continuously. The fan speed can be set to

1%~100% and auto.

• Anti-cold air function.

• If the temperature dierence of T2 changes during

auto fan and causes the fan speed to change, run

mrcool.com41

the current fan speed for 30 seconds rst, the

default interval is the interval before the fan speed

changes, and then judge T2 according to the

current interval after 30 seconds to get the nal

anti-cold air interval.

2. Auto fan action in heating mode:

• Rise Curve

• When T1-Tsc is higher than -2.7°F/-1.5°C, the fan

speed reduces to 80%.

• When T1-Tsc is higher than 0°F/0°C, the fan

speed reduces to 60%.

• When T1-Tsc is higher than 0.9°F/0°C, the fan

speed reduces to 40%.

• When T1-Tsc is higher than 1.8°F/1°C, the fan

speed reduces to 20%.

• Descent Curve

• When T1-Tsc is lower than or equal to

0.9°F/0.5°C, the fan speed increases to 40%.

• When T1-Tsc is lower than or equal to 0°F/0°C,

the fan speed increases to 60%.

• When T1-Tsc is lower than or equal to -2.7°F/-

1.5°C, the fan speed increases to 80%.

• When T1-Tsc is lower than or equal to -5.4°F/-3°C,

the fan speed increases to 100%.

Evaporator Coil Temperature Protection

• O: Compressor stops.

• Decrease: Decrease the running frequency to the

lower level per 20 seconds.

• Hold: Keep the current frequency.

• Resume: No limitation for frequency.

Auto-Mode:

• This mode can be selected with the remote

controller and the temperature setting can be

adjusted between 60.8°F~80°F (16°C~30°C).

Case 1:

• In auto mode, the machine selects cooling,

heating, or fan-only mode on the basis of ΔT

(ΔT=T1-Ts).

ΔT Running Mode

ΔT>3.6°F (2°C) Cooling

-5.4°F (-3°C)≤ΔT≤3.6°F (2°C) Fan-Only

ΔT< -5.4°F (-3°C) Heating

• Indoor fan will run at auto fan speed.

• The louver operates the same as in relevant mode.

• If the machine switches mode between heating

and cooling, the compressor will keep stopping

for a certain time and then choose the mode

according to the ΔT.

Case 2:

In auto mode, the machine selects cooling, heating, or

fan-only mode on the basis of T1, Ts and the outdoor

ambient temperature (T4).

Case 3:

In auto mode, the machine selects cooling, heating, or

fan-only mode on the basis of T1, Ts, outdoor ambient

temperature (T4) and relative humidity (Φ).

PRODUCT FEATURES

mrcool.com 42

Drying Mode:

• In drying mode, the system operates the same as

auto fan in cooling mode.

• All protections are activated and operate the same

as they do in cooling mode.

• Low Room Temperature Protection.

If the room temperature is lower than 50°F/10°C, the

compressor ceases operations and does not resume

until the room temperature exceeds 53.6°F/12°C.

Forced Operation Function:

Press the AUTO/COOL button, the system will run as

shown in the sequence below:

• Forced cooling mode:

The compressor and outdoor fan continue to run and

the indoor fan runs at breeze speed. After running for

30 minutes, the system will switch to auto mode with

a preset temperature of 76°F/24°C.

• Forced auto mode:

Forced auto mode operates the same as normal auto

mode with a preset temperature of 76°F/24°C.

• The unit exits forced operation when it receives

the following signals:

• Switch o

• Changes in:

• mode

• fan speed

• sleep mode

• follow me

Timer Function:

• The timing range is 24 hours.

• Timer On. The machine turns on automatically at

the preset time.

• Timer O. The machine turns o automatically at

the preset time.

• Timer On/O. The machine turns on automatically

at the preset On Time, and then turns o

automatically at the preset O Time.

• Timer O/On. The machine turns o automatically

at the preset O Time and then turns on

automatically at the preset On Time.

• The timer does not change the units operation

mode. If the unit is o now, it does not start up

immediately after the "timer o" function is set.

When the setting time is reached, the timer LED

switches o and the unit running mode remains

unchanged.

• The timer uses relative time, not clock time.

Sleep Function:

• The sleep function is available in cooling, heating,

or auto mode.

• The operational process for sleep mode is as

follows:

• When cooling, the temperature rises 1.8°F/1°C

(to no higher than 86°F/30°C) every hour. After

2 hours, the temperature stops rising and the

indoor fan is xed at a low speed.

• When heating, the temperature decreases

1.8°F/1°C (to no lower than 60.8°F/16°C) every

hour. After 2 hours, the temperature stops

decreasing and the indoor fan is xed at a low

speed. Anti-cold wind function takes priority.

• The operating time for sleep mode is 8 hours, after

which, the unit exits this mode.

• The timer setting is available in this mode.

Auto-Restart Function:

• The indoor unit has an auto-restart module

that allows the unit to restart automatically. The

module automatically stores the current settings

and in the case of a sudden power failure, will

restore those settings automatically within 3

minutes after power returns.

FPMode(46°F(8°C)Heating)

In heating mode, the temperature can be set to as low

as 46°F/8°C, preventing the indoor area from freezing

if unoccupied during severe cold weather.

Follow Me:

• Once the follow me function is active, the remote

control will send a signal every 3 minutes,

with no beeps. The unit automatically sets the

temperature according to the measurements from

the remote control.

• The unit will only change modes if the information

from the remote control makes it necessary, not

from the unit's temperature settings.

• If the unit does not receive a signal for 7 minutes

or you press "Follow Me", the function turns o.

The unit regulates temperature based on its own

sensor and settings.

PRODUCT FEATURES

mrcool.com43

Optional Functions:

Silence (Multi-zone systems do not have this

function)

• Press "Silence" or keep pressing the Fan button

for more than 2 seconds on the remote control to

enable the SILENCE function. While this function

is active, the compressor frequency is maintained

at a lower level than F3. The indoor unit will run

at a faint breeze (1%), which reduces noise to the

lowest possible level.

• When matched with a multi-zone, this function is

disabled.

ECO Function (Multi-zone systems do not have this

function)

• Used to enter the energy ecient mode.

• Under cooling mode, press the ECO button, the

remote controller will adjust the temperature

automatically to 75°F/24°C, the fan speed

to AUTO to save energy (but only if the set

temperature is less than 75°F/24°C). If the

set temperature is more than 75°F/24°C and

86°F/30°C, press the ECO button, the fan speed

will change to AUTO, the set temperature will

remain unchanged.

• When pressing the ECO button, modifying the

mode, or adjusting the set temperature to less

than 75°F/24°C, the system will cease the ECO

operation.

• Operation time in ECO mode is 8 hours. After 8

hours the system ceases this mode.

Electrical Energy Consumption Control Function

(Multi-zone systems do not have this function)

Press the "Gear" button on the remote controller to

enter the energy ecient mode in a sequence of the

following:

Turn o the unit or activate ECO, sleep, Super Cool,

46°F/8°C Heating, Silence, or Self Clean Functions to

cease this mode.

Breeze Away (for some models) (Multi-zone systems

do not have this function)

• This feature avoids direct airow blowing on the

body and makes you feel in the cool air.

• NOTE: This feature is available under cooling

mode, fan-only mode, and drying mode.

Active Clean Function (for some models) (Multi-zone

systems do not have this function)

• The Active Clean Technology washes away dust,

mold, and grease that may cause odors when it

adheres to the heat exchanger by automatically

freezing and then rapidly thawing the frost. The

internal wind wheel then keeps operating to blow-

dry the evaporator, thus preventing the growth of

mold and keeps the inside clean.

• When this function is turned on, the indoor unit

display window appears "CL", after 20 to 45

minutes, the unit will turn o automatically and

cancel Active Clean Function.

PRODUCT FEATURES

mrcool.com 44

TROUBLESHOOTING

5.1 Safety Caution

WARNING

Besuretoturnoallpowersuppliesordisconnectallwirestoavoidelectricshock.Whilecheckingthe

indoor/outdoorPCB,pleaseequipyourselfwithanti-staticglovesorawriststraptoavoiddamaging

the board.

Electricitywillremainincapacitorsevenwhenthepowersupplyiso.Ensurethecapacitorsarefully

discharged before troubleshooting

Note: If using the inverter test tool for maintenance, remove the big handle from the unit, take out

the detection cable, take out the female end of the cable, and connect the inverter testing tool. After

maintenance is completed, insert the female end back into the port.

Note: This picture is for reference only. Actual appearance may vary.

mrcool.com45

TROUBLESHOOTING

5.2ErrorDisplay(IndoorUnit)

Display Error Information Solution

Forced cooling (not an error code) --

EC 07

ODU fan speed out of control TS23

EC 51

ODU EEPROM parameter error TS19

EC 52

ODU coil temp. sensor (T3) error TS25

EC 53

ODU ambient temp. sensor (T4) error TS25

EC 54

COMP. discharge temp. sensor (TP) error TS25

EC 56

IDU coil outlet temp. sensor (T2B) error (multi-zone) TS25

EC C1

Other IDU refrigerant sensor detects leakage (multi-zone) TS39

EH 00

IDU EEPROM Malfunction TS19

EH 03

IDU fan speed out of control TS23

EH 0A

IDU EEPROM parameter error TS19

EH 0E

Water-level alarm malfunction TS27

EH 12

Main unit or secondary units malfunction TS40

EH 3A

External fan DC bus voltage is too low protection TS37

EH 3b

External fan DC bus voltage is too high fault TS37

EH 60

IDU room temp. sensor (T1) error TS25

EH 61

IDU evaporator coil temp. sensor (T2) error TS25

EH bA

Communication error between the indoor unit and external fan module TS37

EH C1

Refrigerant sensor detects leakage TS39

EH C2

Refrigerant sensor is out of range and leakage is detected TS39

EH C3

Refrigerant sensor is out of range TS38

EL 01

IDU & ODU communication error TS20

EL 0C

System lacks refrigerant TS26

EL 11

Communication malfunction between main unit and secondary units TS40

FH 07

Communication malfunction between indoor unit and auto-lifting panel TS38

FH CC

Refrigerant sensor error TS28

PC 00

ODU IPM module protection TS29

PC 01

ODU voltage protection TS34

PC 02

Compressor top (or IPM) temp. protection TS31

PC 03

Pressure protection (low or high pressure) (for some models) TS30

PC 04

Inverter compressor drive error TS35

PC 0L

Low ambient temperature protection (for some models) --

For Other Errors:

The display board may show a garbled code or

a code undened by the service manual. Ensure

that this code is not a temperature reading.

Troubleshooting:

Test the unit using the remote control. If the unit

does not respond to the remote, the indoor PCB

requires replacement. If the unit responds, the

display board requires replacement.

mrcool.com 46

TROUBLESHOOTING

5.3InformationInquiry&Setting

In order to enter to engineering mode and check the data of the system (data checking mode), please

follow these steps:

• Make sure that the system is in standby status or working in non-locked conditions.

• Press the "Power" + "Fan" buttons together for 7s until the remote controller screen shows "0", and

also "Auto, Cool, Dry, Heat, Battery" icons will be displayed at the same time.

• Press the "UP" or "Down" buttons to choose dierent channel numbers that want to check (from

0-30) on the remote controller, and then the display will show the parameter value.

Channel Code Meaning Remark

0 Error Code

Refer to the next list of error codes

Empty means no error code

1 T1 Room temperature Actual data, °C

2 T2 Indoor coil temperature Actual data, °C

3 T3 Outdoor coil temperature Actual data, °C

4 T4 Ambient temperature Actual data, °C

5 TP Discharge temperature Actual data, °C

6 FT Targeted frequency Actual data

7 Fr Actual frequency Actual data

8 dl Running current 3.2A-3

9 Ac AC voltage

10 Sn Reserved

11 -- Indoor operating mode

0-O; 1-Cooling; 2-Heating;

3-Fan Only; 4-Drying; 5-Auto;

7-Defrosting; 12-Active Clean

12 Pr Outdoor fan speed Actual data/8

13 Lr EXV opening steps Actual data/8

14 Ir Indoor fan speed Actual data/8

15 Hu Humidity (if a sensor is there) Actual data, %

16 TT Set temperature including compensation Actual data, °C

17 nA Reserved

18 nA Reserved

19 Uo Outdoor DC bus voltage

20 oT Target Frequency calculated by indoor Without limitation

21 nA

Reserve

22~30 nA

Note:

1. The channel number indicates a certain parameter value (Check next table).

2. The indoor unit display will show the code for 2s and then the parameter value.

3. In the engineering mode, the other keys or operations are invalid except for the following buttons

"Power", "Up", "Down", and "Ok".

4. In order to exit from the engineering mode, press the "Power" + "Fan" buttons together for 2s to

quit checking and return back to the home screen

5. The engineering mode will be exited if there is no valid input data for 60s.

mrcool.com47

TROUBLESHOOTING

Error Code of Engineer Mode:

Display Error Information

EH 00

IDU EEPROM malfunction

EH 0A

Indoor EEPROM parameter error

EL 01

IDU & ODU communication error

EH bA

Communication error between indoor unit and indoor external fan module

EH 30

Parameters error of indoor external fan

EH 35

Phase failure of indoor external fan

EH 36

Indoor external fan current sampling bias fault

EH 37

Indoor external fan zero speed failure

EH 38

Indoor external fan stall failure

EH 39

Out of step failure of indoor external fan

EH 3A

Low voltage protection of indoor external fan DC bus

EH 3b

Indoor external fan DC bus voltage is too high fault

EH 3E

Indoor external fan overcurrent fault

EH 3F

Indoor external fan module protection/hardware overcurrent protection

EH 03

IDU fan speed out of control

EC 51

ODU EEPROM parameter error

EC 52

ODU coil temp. sensor (T3) error

EC 53

ODU ambient temp. sensor (T4) error

EC 54

COMP. Discharge temp. sensor (TP) error

EC 55

ODU IPM module temp. sensor (TH) error

EC 0d

Outdoor unit malfunction

EH 60

IDU room temp. sensor (T1) error

EH 61

Evaporator coil temperature sensor T2 is in open circuit or short circuit

EC 71

Outdoor external fan overcurrent fault

EC 75

Outdoor external fan module protection/hardware overcurrent protection

EC 72

Outdoor external fan phase failure

EC 74

Outdoor external fan current sampling bias fault

EC 73

Zero speed failure of outdoor unit DC fan

EC 07

ODU fan speed out of control

EH b5

Intelligent eye communication failure

EL 0C

System lacks refrigerant

EH 0E

Water-level alarm malfunction

EH 0F

Intelligent eye malfunction

FH 07

Communication malfunction between indoor unit and auto-lifting panel

PC 00

ODU IPM module protection

PC 10

Over low voltage protection

PC 11

Over voltage protection

PC 12

DC voltage protection

mrcool.com 48

TROUBLESHOOTING

Display Error Information

PC 02

Top temperature protection of compressor High temperature protection of IPM module

PC 40

Communication error between outdoor main chip and compressor driven chip

PC 41

Current Input detection protection

PC 42

Compressor start error

PC 43

Lack of phase (3 phase) protection

PC 44

Outdoor unit zero speed protection

PC 45

341PWM error

PC 46

Compressor speed malfunction

PC 49

Compressor over current protection

PC 06

Compressor discharge temperature protection

PC 08

Outdoor current protection

PH 09

Anti-cold air in heating mode

PC 0f

PFC module malfunction

PC 30

System overpressure protection

PC 31

System pressure is too low protection

PC 03

Pressure protection

PC 0L

Outdoor low ambient temperature protection

PH 90

Evaporator coil temperature over high protection

PH 91

Evaporator coil temperature over low protection

PC 0A

Condenser high temperature protection

PH 0C

Indoor unit humidity sensor failure

LH 00

Frequency limit caused by T2

LH 30

Indoor external fan current limit

Lh 31

Indoor external fan voltage limit

LC 01

Frequency limit caused by T3

LC 02

Frequency limit caused by TP

LC 05

Frequency limit caused by voltage

LC 03

Frequency limit caused by current

LC 06

Frequency limit caused by PFC

LC 30

Frequency limit caused by high pressure

LC 31

Frequency limit caused by low pressure

LH 07

Frequency limit caused by remote controller

----

IDUs comm. conict (match with multi outdoor unit)

No malfunction and protection

mrcool.com49

TROUBLESHOOTING

In order to enter to the engineering mode and check the advanced function settings please follow

these steps.

Ifyouwanttocheckthecurrentfunctionssetvalue(PresettingPage):

1. First, you will need to disconnect the power supply from the unit and wait 1 minute.

2. Then re-connect the power supply to the unit and it should enter standby mode.

3. Press the "Power" + "Fan" buttons together for 7s until the remote controller screen shows "0",

then the "Auto, Cool, Dry, Heat, Battery" icons will be displayed at the same time.

4. Press "UP" or "Down" buttons to choose dierent channel numbers that you want to check (from

0-30) on the remote controller.

5. The press the "Power" button for 2s until the remote controller screen shows "Ch".

6. Press the "OK" button to query the current function set value while the remote controller shows

"Ch" and the function set vale will be shows on the indoor units display.

If you want to change the current functions set value:

1. First, you will need to disconnect the power supply form the unit and wait 1 minute.

2. Then connect the power supply again to the unit and it should enter standby mode.

3. Press the "Power" + "Fan" buttons together for 7s until the remote controller screen shows "0" then

the "Auto, Cool, Dry, Heat, Battery" icons will be displayed at the same time.

4. Press the "UP" or "Down" buttons to choose dierent channel numbers that you want to change

(from 0~30) on the remote controller.

5. The press the "Power" button for 2s until the remote controller screen shows "Ch".

6. Press the "Up" or "Down" button to choose the desired set value from the screen of the remote

control.

7. The press "OK" to send the new set value to the indoor unit, the indoor will display "CS" which

means that the new set value is uploaded successfully.

8. Finally, disconnect the power supply again from the unit and wait for 10 minutes then re-connect.

Note:

1. The channel number indicates a certain function and each number will be showed on the indoor

units screen indicates the current function set value (Check the table following table).

2. In the engineering mode the other keys or operations are invalid except for the following buttons

"Power", "Up", "Down", and "OK".

3. I order to set a new set value successfully you need to nish the steps (from 2 to 7) within 1 minute

only.

4. The engineering mode will be exited if there is no valid input data for 60s.

5. In order to exit from the engineering mode please follow these steps.

• Press the "Power" button for 2s until the remote controller screen shows "0".

• The press the "Power" + "Fan" buttons together for 2s to quit the engineering mode and back to

the home screen.

Advanced Function Setting:

mrcool.com 50

TROUBLESHOOTING

Channel Function Parameter Value Meaning Remark

0 Capacity setting (Btu/h) 1-100K

1 Auto-restart function

0- Inactive

1- Active

Fan control when Ts

reached

1- Fan stop

2- Fan runs at lowest RPM

3- Fan runs at setting RPM

4~11- Fan stops for 4 mins and runs for 1 min

3 Mode lock

CH- Cooling and heating (all modes)

HH- Heating only (Heating + Fan only)

CC- Cooling only (Cooling + Drying + Fan only)

nU- Cooling and heating without Auto

Remote controller will change as

well.

Lowest setting

temperature

16-24

Remote controller will change as

well.

Highest setting

temperature

25-30

Remote controller will change as

well.

6 Reserved

7 Twins selection 0- No twins; 1- Master unit; 2- Secondary unit

8 / Nothing to set

9 / Nothing to set

10 / Nothing to set

Min. frequency

limitation in cooling

mode

10,11,12,..., 49,50,-- (cancel)

Min. frequency

limitation in heating

mode

20,21,22,...,149,250,-- (cancel)

Max. frequency

selection in T4

limitation of Zone 6

20,21,22,...,149,250,-- (cancel)

14 / Nothing to set

Frequency selection

of outdoor forced-

operation

10,11,12,...,249,250,-- (cancel)

16 One button reset rS- Reset

17 nA Nothing to set

18 Capacity setting (kW) 23,26,32,35,51,72,120,-- (cancel)

Max. frequency

selection in cooling

mode

40,41,42,..,83,83,-- (cancel)

Max. frequency

selection in heating

mode

40,41,42,...,83,84,-- (cancel) Without limitation

Cooling temperature

compensation

-3.0,-2.5,-2.0,...,3.0,3.5,-- (cancel)

Heating temperature

compensation

-6.5,-6.0,-5.5,...,0.5,1.0,1.5,...,7.0,7.5,-- (cancel)

Max. fan speed

selection in cooling

-41,-40,-39,...,19,20,-- (cancel)

mrcool.com51

TROUBLESHOOTING

Channel Function Parameter Value Meaning Remark

Min. fan speed

selection in cooling

-41,-40,-39,...,19,20,-- (cancel)

Max. fan selection in

heating

-41,-40,-39,...,19,20,-- (cancel)

Min. fan speed

selection in heating

-41,-40,-39,...,19,20,-- (cancel)

27 Reserved Nothing to set

Anti-cold air stop fan

temperature

16~28

Remote controller will change as

well.

29 Reserved Nothing to set

30 Reserved Nothing to set

5.4 Error Diagnosis Without Error Code

Remote Maintenance:

Suggestion: When troubles occur, please check the following points with the customer before eld maintenance.

No. Problem Solution

1 Unit will not start TS14-TS15

2 The power switch is on but fans will not start TS14-TS-15

3 The temperature on the display board cannot be set TS14-TS-15

4 Unit is on but the air is not cold/hot TS14-TS-15

5 Unit runs but shortly stops TS14-TS-15

6 The unit starts up and stops frequently TS14-TS-15

7 Unit runs continuously but insucient cooling/heating TS14-TS-15

8 Cool cannot change to heat TS14-TS-15

9 Unit is noisy TS14-TS-15

Field Maintenance:

No. Problem Solution

1 Unit will not start TS16-TS17

2 Compressor will not start but fans run TS16-TS17

3 Compressor and condenser fan will not start TS16-TS17

4 Air handler fan will not start TS16-TS17

5 Condenser fan will not start TS16-TS17

6 Unit runs but shortly stops TS16-TS17

7 Compressor short-cycles due to overload TS16-TS17

8 High suction pressure TS16-TS17

9 Low discharge pressure TS16-TS17

10 High suction pressure TS16-TS17

11 Low suction pressure TS16-TS17

12 Unit runs continuously but insucient cooling TS16-TS17

13 Too cool TS16-TS17

14 Compressor is noisy TS16-TS17

15 Horizontal louver cannot revolve TS16-TS17

mrcool.com 52

TROUBLESHOOTING

1. Remote

Maintenance

Electrical Circuit Refrigerant Circuit

Possible causes of

trouble

Power failure

The main power tripped

Loose connections

Faulty transformer

The voltage too high or too low

Theremotecontrolispoweredo

Broken the remote control

Dirtyairlter

Dirtycondenserns

Thesettingtemperatureishigher/lower

thantheroom's(cooling/heating)

Theambienttemperatureistoohigh/

lowwhenthemodeiscooling/heating

Fan mode

Silence function is activate

Frostinganddefrostingfrequency

Unit will not start √ √ √ √ X X X X X X X X X X

The power switch is

on but fans will not

start

X X √ √ √ X X X X X X X X X

The temperature

on the playboard

cannot be set

X X X X X √ √ X X X X X X X

Unit is on but the air

is not cold/hot

X X X X X X X X X √ √ √ X X

Unit runs but shortly

stops

X X X X √ X X X √ √ X X X

The unit startup and

stops frequently

X X X X √ X X X X X √ X X √

Unit runs

continuously but

insucient cooling/

heating

X X X X X X X √ √ √ √ X √ X

Cool cannot change

to heat

X X X X X X X X X X X X X X

Unit is noisy X X X X X X X X X X X X X X

Testmethod/

remedy

Test voltage

Close the power switch

Inspect connections - tighten

Change the transformer

Test voltage

Replace the battery of the

remote control

Replace the remote control

Clean or replace

Clean

Adjustthesettingtemperature

Turn on the unit later

Adjusttocoolmode

Turnothesilencefunction

Turn on the unit later

mrcool.com53

TROUBLESHOOTING

1. Remote

Maintenance

Others

Possible causes of

trouble

Heavy load condition

Loosen hold down bolts or screws

Bad airproof

The air inlet or outlet of either unit is

blocked

Interference from cell phone towers and

remote boosters

Shipping plates remain attached

Unit will not start X X X X X X

The power switch is

on but fans will not

start

X X X X √ X

The temperature

on the playboard

cannot be set

X X X X X X

Unit is on but the air

is not cold/hot

X X X X X X

Unit runs but shortly

stops

X X X X X X

The unit startup and

stops frequently

X X X √ X X

Unit runs

continuously but

insucient cooling/

heating

√ X √ √ X X

Cool cannot change

to heat

X X X X X X

Unit is noisy X √ X X X √

Testmethod/

remedy

Check heat load

Tighten bolts and screws

Close all windows and doors

Remove the obstacles

Reconnect the power or press

ON/OFFbuttonontheremoteto

restart operation

Remove item

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TROUBLESHOOTING

2. Field

Maintenance

Refrigerant Circuit Others

Possible

causes of

trouble

Compressor stuck

Shortage of refrigerant

Restrictedliquidline

Dirtyairlter

Dirty evaporator coil

Insucientairthrough

evaporator coil

Overcharge of refrigerant

Dirty or partially blocked

condenser

Air or incompressible gas in

refrigerant cycle

Short cycling of condensing air

High temperature condensing

medium

Insucientcondensingmedium

Broken compressor internal parts

Inecientcompressor

Expansion valve obstructed

Expansion valve or capillary tube

close completely

Leaking power element on

expansion valve

Poor installation of feeler bulb

Heavy load condition

Loosenholddownboltsand/or

screws

Shipping plates remain attached

Poor choices of capacity

Contact of piping with other

piping or external plate

Unit will not

start

X X X X X X X X X X X X X X X X X X X X X X X

Compressor

will not start

but fans run

√ X X X X X X X X X X X X X X X X X X X X X X

Compressor

and condenser

fan will not

start

X X X X X X X X X X X X X X X X X X X X X X X

Air handler fan

will not start

X X X X X X X X X X X X X X X X X X X X X X X

Condenser fan

will not start

X X X X X X X X X X X X X X X X X X X X X X X

Unit runs but

shortly stops

X √ √ X X X √ √ X X X X X X X √ √ X X X X X X

Compressor

short-cycles

due to overload

X √ X X X X √ √ X X X X X X X X X X X X X X X

High discharge

pressure

X X X X X X √ √ √ √ √ √ X X X X X X X X X X X

Low discharge

pressure

X √ X X X X X X X X X X X √ X X X X X X X X X

Testmethod/

remedy

Replace the compressor

Leak test

Replace restricted part

Clean or replace

Clean coil

Check fan

Change charged refrigerant

volume

Clean condenser or remove

obstacle

Purge, evacuate and recharge

Removeobstructiontoairow

Remove obstruction in air or

waterow

Remove obstruction in air or

waterow

Replace compressor

Testcompressoreciency

Replace valve

Fix feeler bulb

Check heat load

Tighten bolts or screws

Remove them

Choose system of larger capacity

or add another system

Rectify piping so as to not contact

with each other or with external

plate

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TROUBLESHOOTING

2. Field

Maintenance

Refrigerant Circuit Others

Possible causes of

trouble

Compressor stuck

Shortage of refrigerant

Restrictedliquidline

Dirtyairlter

Dirty evaporator coil

Insucientairthroughevaporator

coil

Overcharge of refrigerant

Dirty or partially blocked condenser

Air or incompressible gas in

refrigerant cycle

Short cycling of condensing air

High temperature condensing

medium

Insucientcondensingmedium

Broken compressor internal parts

Inecientcompressor

Expansion valve obstructed

Expansion valve or capillary tube

close completely

Leaking power element on

expansion valve

Poor installation of feeler bulb

Heavy load condition

Loosenholddownboltsand/or

screws

Shipping plates remain attached

Poor choices of capacity

Contact of piping with other piping

or external plate

High suction

pressure

X X X X X X √ X X X X X X √ X X X √ √ X X X X

Low suction

pressure

X √ √ √ √ √ X X X X X X X X √ √ √ X X X X X X

Unit runs

continuously but

insucient cooling

X √ √ √ √ √ X √ √ √ X X X √ X X X X √ X X √ X

Too Cool X X X X X X X X X X X X X X X X X X X X X X X

Compressor is

noisy

X X X X X X √ X X X X X √ X X X X X X √ √ X √

Horizontal louver

cannot revolve

X X X X X X X X X X X X X X X X X X X X X X X

Testmethod/

remedy

Replace the compressor

Leak test

Replace restricted part

Clean or replace

Clean coil

Check fan

Change charged refrigerant volume

Clean condenser or remove obstacle

Purge, evacuate and recharge

Removeobstructiontoairow

Removeobstructioninairorwaterow

Replace compressor

Testcompressoreciency

Replace valve

Fix feeler bulb

Check heat load

Tighten bolts or screws

Remove them

Choose system of larger capacity or add

another system

Rectify piping so as to not contact with

each other or with external plate

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TROUBLESHOOTING

2. Field

Maintenance

Electrical Circuit

Possible causes of

trouble

Power Failure

Blown fuse or varistor

Loose connections

Shorted or broken wires

Safety device opens

Faultythermostat/room

temperature sensor

Wrong setting place of

temperature sensor

Faulty transformer

Shorted or open capacitor

Faulty magnetic contactor for

compressor

Faulty magnetic contactor for fan

Low voltage

Faulty stepping motor

Shorted or grounded compressor

Shorted or grounded fan motor

Unit will not start √ √ √ √ √ X X √ X X X X X X X

Compressor will

not start but fans

run

X X X √ X √ X √ √ X X X X √ X

Compressor and

condenser fan will

not start

X X X √ X √ X X X √ X X X X X

Air handler fan will

not start

X X X √ X X X X √ X √ X X X √

Condenser fan will

not start

X X X √ X √ X X √ X √ X X X √

Unit runs but

shortly stops

X X X X X X X X X √ X √ X X X

Compressor

short-cycles due to

overload

X X X X X X X X X √ X √ X X X

High discharge

pressure

X X X X X X X X X X X X X X X

Low discharge

pressure

X X X X X X X X X X X X X X X

Testmethod/

remedy

Test voltage

Inspect fuse type & size

Inspect connections - tighten

Test circuits with tester

Test continuity of safety device

Testcontinuityofthermostat/sensor

& wiring

Place the temperature sensor at the

central of the air inlet grille

Check control circuit with tester

Check capacitor with tester

Test continuity of coil & contacts

Test voltage

Replace the stepping motor

Check resistance with multimeter

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TROUBLESHOOTING

2. Field

Maintenance

Electrical Circuit

Possible causes of

trouble

Power Failure

Blown fuse or varistor

Loose connections

Shorted or broken wires

Safety device opens

Faultythermostat/room

temperature sensor

Wrong setting place of temperature

sensor

Faulty transformer

Shorted or open capacitor

Faulty magnetic contactor for

compressor

Faulty magnetic contactor for fan

Low voltage

Faulty stepping motor

Shorted or grounded compressor

Shorted or grounded fan motor

High suction

pressure

X X X X X X X X X X X X X X X

Low suction

pressure

X X X X X X X X X X X X X X X

Unit runs

continuously but

insucient cooling

X X X X X X X X X X X X X X X

Too cool X X X X X X √ √ X X X X X X X

Compressor is

noisy

X X X X X X X X X X X X X X X

Horizontal louver

can not revolve

X X √ √ X X X X X X X X √ X X

Testmethod/

remedy

Test voltage

Inspect fuse type & size

Inspect connections - tighten

Test circuits with tester

Test continuity of safety device

Testcontinuityofthermostat/sensor

& wiring

Place the temperature sensor at the

central of the air inlet grille

Check control circuit with tester

Check capacitor with tester

Test continuity of coil & contacts

Test voltage

Replace the stepping motor

Check resistance with multimeter

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TROUBLESHOOTING

5.5 Quick Maintenance by Error Code

If you do not have the time to test which specic parts are faulty, you can change the required parts according to

the error code. You can nd the parts to replace by error code in the following table.

PartRequiring

Replacement

Error Code

EH00/

EH 0A

EL 01 EH 03 EH 60 EH 61 EL 0C

EHC1/

EH C2

EH 0E EC 53 EH 0b

Indoor PCB

√ √ √ √ √ √

√

Outdoor PCB

√

X X X X X X

√

Indoor Fan Motor

X X

√

X X X X X X X

T1 Sensor

X X X

√

X X X X X X

T2 Sensor

X X X X

√ √

√

X X

T3 Sensor

X X X X X X X X X X

T4 sensor

X X X X X X X X

√

Reactor

√

X X X X X X X X

Compressor

X X X X X X X X X X

Additional

Refrigerant

X X X X X

√ √ √

X X

Water-Level Switch

X X X X X X X

√

X X

Water Pump

X X X X X X X

√

X X

Display Board

X X X X X X X X X

√

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TROUBLESHOOTING

PartRequiring

Replacement

Error Code

EC 54 EC 51 EC 52 EC 56 EC 07 PC 00 PC 01 PC 02 PC 04 PC 03

FHCC/

EH C3

Indoor PCB

X X X X X X X X X X

√

Outdoor PCB

√ √ √ √ √ √ √ √ √ √

Outdoor Fan

Motor

X X X X

√ √

X X

T3 Sensor

X X

√

X X X X X X X X

TP Sensor

√

X X X X X X X X X X

T2B Sensor

X X X

√

X X X X X X X

Refrigerant

Sensor

X X X X X X X X X X

√

Reactor Sensor

X X X X X X

√

X X X X

Compressor

X X X X X

√

X X

√

X X

IPM Module

Board

X X X X X

√ √ √ √

X X

Pressure

Protector

X X X X X X X X X

√

Additional

Refrigerant

X X X X X X X X X

√

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TROUBLESHOOTING

5.6 Troubleshooting by Error Code

EH00/EH0A/EC51:EEPROMMalfunctionErrorDiagnosisandSolution.

Description: Indoor PCB main chip does not receive feedback from EEPROM chip.

Recommended parts to prepare:

• Indoor PCB

• Outdoor PCB

Troubleshooting and repair:

Remarks:

EEPROM: A read-only memory whose contents can be erased and reprogrammed using a puled

voltage. The location of the EEPROM chip on the indoor PCB is shown in the following images:

Note: These pictures are for reference, actual appearance may vary.

Troubleshooting and repair of the compressor driven chip EEPROM parameter error and

communication error between the outdoor main chip and compressor driven chip are the same

as EC 51.

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TROUBLESHOOTING

EL 01: IDU & ODU Communication Error Diagnosis and Solution.

Description: Indoor unit cannot communicate with the outdoor unit.

Recommended parts to prepare:

• Indoor PCB

• Outdoor PCB

• Reactor

Troubleshooting and repair:

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TROUBLESHOOTING

Remarks:

• Use a multimeter to test the DC voltage between 2 port (or S or L2 port) and 3 port (or N or S port)

of outdoor unit. The red pin of the multimeter connects with 2 port (or S or L2 port) while the black

pin is for 3 port (or N or S port).

• When AC is running normal the voltage will move alternately between -25V to 25V.

• If the outdoor unit has a malfunction, the voltage will alternate with a positive value.

• If the indoor unit has a malfunction the voltage will be a certain value.

• Use a multimeter to test the resistance of the reactor which does not connect with the capacitor.

• The normal value should be around zero ohms. Otherwise the reactor has a malfunction.

Note: The pictures and the values are for reference only, actual condition and specic values may vary.

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TROUBLESHOOTING

485Communication(S1,S2Communication)

Recommended parts to prepare:

• Signal wires

• Magnet ring

• Indoor PCB

• Outdoor PCB

Troubleshooting and repair:

mrcool.com 64

TROUBLESHOOTING

EH03/EC07:FanSpeedOutofControlDiagnosisandSolution.

Description: When the indoor/outdoor fan speed keeps too low or too high for a certain time, the unit

ceases operation and the LED displays a fault.

Recommended parts to prepare:

• Connection wires

• Fan assembly

• Fan motor

• PCB

Troubleshooting and repair:

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TROUBLESHOOTING

Index:

1. IndoororOutdoorDCfanmotor(controlchipisinfanmotor)

Power on and make sure the unit is in standby, measure the voltage of pin1-pin3, pin4-pin3 on the fan

motor connector. If the value of the voltage is not in the range showing in the tables below the PCB

will have problems and will need to be replaced.

NO. Color Signal Voltage

1 Red Vs/Vm 192V~380V

2 --- --- ---

3 Black GND 0V

4 White Vcc 13.5-16.5V

5 Yellow Vsp 0~6.5V

6 Blue FG 13.5-16.5V

Index:

1. OutdoorDCfanmotor(controlchipisinoutdoorPCB)

Release the UVW connector and measure the resistance of U-V, U-W, V-W. If the resistance is not equal

to each other the fan motor has a problem and needs to be replaced. Otherwise the PCB has a

problem and needs to be replaced.

mrcool.com 66

TROUBLESHOOTING

EH60/EH61/EC53/EC52/EC54/EC56:OpenCircuitorShortCircuitof

Temperature Sensor Diagnosis and Solution.

Description: If the sampling voltage is lower than 0.06V or higher than 4.94V, the LED displays a fault

code.

Recommended parts to prepare:

• Connection wires

• Sensors

• PCB

Troubleshooting and repair:

Note: The picture and the value are for reference only, actual condition and specic values may vary.

mrcool.com67

TROUBLESHOOTING

EL 0C: System Lacks Refrigerant Diagnosis and Solution.

Description: Judging the abnormality of the refrigeration system according to the number of

compressor stops and the changes in operating parameters caused by excessive exhaust temperature.

Recommended parts to prepare:

• Indoor PCB

• Additional refrigerant

Troubleshooting and repair:

mrcool.com 68

TROUBLESHOOTING

EH 0E: Water-Level Alarm Malfunction Diagnosis and Solution.

Description: If the sampling voltage is not 5V, the LED displays a fault code.

Recommended parts to prepare:

• Connection wires

• Water-level switch

• Water pump

• Indoor PCB

Troubleshooting and repair:

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TROUBLESHOOTING

PC 00: ODU IPM Module Protection Diagnosis and Solution.

Description: When the voltage signal the IPM sends to the compressor drive chip is abnormal, the LED

displays a fault code.

Recommended parts to prepare:

• Connection wires

• IPM module board

• Outdoor fan assembly

• Compressor

• Outdoor PCB

Troubleshooting and repair:

mrcool.com 70

TROUBLESHOOTING

PC 01: ODU Voltage Protection Diagnosis and Solution.

Description: Abnormal increases or decreases in voltage are detected by checking the specied

voltage detection circuit.

Recommended parts to prepare:

• Power supply wires

• IPM module board

• PCB

• Reactor

Troubleshooting and repair:

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TROUBLESHOOTING

PC 04: Inverter Compressor Drive Error Diagnosis and Solution.

Description: An abnormal inverter compressor drive is detected by a special detection circuit,

including communication, signal detection, voltage detection, compressor rotation speed signal

detection, and so on.

Recommended parts to prepare:

• Connection wires

• IPM module board

• Outdoor fan assembly

• Compressor

• Outdoor PCB

Troubleshooting and repair:

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TROUBLESHOOTING

PC03:PressureProtection(LoworHighPressure)DiagnosisandSolution.

Description: The outdoor pressure switch cut o the system due to high pressure (if pressure is

higher than 638 PSI.(4.4MPa)). Or the outdoor pressure switch cut o the system due to low pressure

(if the pressure is lower than 18.85 PSI.(0.13MPa) the LED will display a fault code.

Recommended parts to prepare:

• Connection wires

• Pressure switch

• Outdoor fan

• Outdoor main PCB

• Refrigerant

Troubleshooting and repair:

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TROUBLESHOOTING

PC 03: Cont.

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TROUBLESHOOTING

PC02:CompressorTop(orIPM)Temp.ProtectionDiagnosisandSolution.

Description: (For some models with overload protection). If the sampling voltage is not 5V, the LED

will display a fault code. If the temperature of the IPM module is higher than a certain value, the LED

will display a fault code.

Recommended parts to prepare:

• Connection wires

• Outdoor PCB

• IPM module board

• High pressure protector

• System blockages

Troubleshooting and repair:

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TROUBLESHOOTING

PC 0L: Low Ambient Temperature Protection.

Description: It is a protection function. When the compressor is o and the outdoor ambient

temperature (T4) is lower than -35°C for 10s, the AC will stop and display the fault code.

When the compressor is on and the outdoor ambient temperature (T4) is lower than -40°C for 10s, the

AC will stop and display the fault code.

When the outdoor ambient temperature (T4) is no lower than -32°C for 10s, the unit will exit the

protection.

EH b3: Communication malfunction Between Wire and Master Control Diagnosis

and Solution.

Description: If the indoor PCB does not receive feedback from the wired controller, the error displays

on the wired controller..

Recommended parts to prepare:

• Connection wires

• Indoor PCB

• Wired Controller

Troubleshooting and repair:

mrcool.com 76

TROUBLESHOOTING

EH bA: Communication Error Between the Indoor Unit and the External Fan

module/EH3A:ExternalFanDCBusVoltageistooLowProtection/EH3b:External

fan DC bus voltage is too High Fault Diagnosis and Solution.

Description: The indoor unit does not receive the feedback from the external fan module during 150s

or the indoor unit receives abnormal increases or decreases in voltage from the external fan module.

Recommended parts to prepare:

• Indoor main PCB

Troubleshooting and repair:

mrcool.com77

TROUBLESHOOTING

FHCC:RefrigerantSensorError/EHC3:RefrigerantSensorisOutofRange

Diagnosis and Solution.

Description: Indoor unit receives a fault signal for 10s or the indoor unit does not receive feedback

from the refrigerant sensor for 150s.

Recommended parts to prepare:

• Connection wires

• Sensors

• Indoor man PCB

Troubleshooting and repair:

mrcool.com 78

TROUBLESHOOTING

EHC1:RefrigerantSensorDetectsLeakage/EHC2:RefrigerantSensorisOutof

Range and Leakage is Detected Diagnosis and Solution

Description: The refrigerant sensor detects a concentration higher than or equal to 10%*LFL for 10

seconds or the refrigerant sensor detects a concentration higher than or equal to 20%*LFL or the multi

model receives the refrigerant leakage protection fault sent by the outdoor unit.

Multi-zone: Only the buzzer of the indoor unit that detects refrigerant leakage continues to sound the

alarm, the shortest sound is 10 seconds and the longest sound is 5 minutes (you can press any key

on the remote control, wired controller, APP, and so on to eliminate the alarm) and any other non-

refrigerant leakage fault the indoor unit will only display ECC1 and the buzzer will not make a sound.

Recommended parts to prepare:

• Additional refrigerant

Troubleshooting and repair:

mrcool.com79

TROUBLESHOOTING

EL 11: Communication Malfunction Between the Main unit and Secondary Units

(forTwinSystems)DiagnosisandSolution.

Description: When set in twin systems the master unit and slave unit cannot be recognized normally.

Recommended parts to prepare:

• Connection wires

• Indoor man PCB

Troubleshooting and repair:

EH12:MainUnitorSecondaryUnitMalfunction(forTwinSystem)Diagnosisand

Solution.

Description: When set in twin systems, one indoor unit displays this error code which means another

unit if faulty. Check another indoor unit's error code and then follow the prescribed solutions to

resolve the malfunction.

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TROUBLESHOOTING

5.7 Check Procedures

WARNING

Besuretoturnoallpowersuppliesordisconnectallwirestoavoidelectricshock.Operateonlyafter

thecompressorandcoilhasreturnedtonormaltemperatureincaseofinjury.

1. Disconnect the temperature sensor from the PCB.

2. Measure the resistance value of the sensor using a multi-meter.

3. Check corresponding temperature sensor resistance value table.

Note: The picture and the value are for reference only, actual condition and specic values may vary.

Temperature Sensor Check:

mrcool.com81

°C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm

-20 -4 542.7 20 68 68.66 60 140 13.59 100 212 3.702

-19 -2 511.9 21 70 65.62 61 142 13.11 101 214 3.595

-18 0 483 22 72 62.73 62 144 12.65 102 216 3.492

-17 1 455.9 23 73 59.98 63 145 12.21 103 217 3.392

-16 3 430.5 24 75 57.37 64 147 11.79 104 219 3.296

-15 5 406.7 25 77 54.89 65 149 11.38 105 221 3.203

-14 7 384.3 26 79 52.53 66 151 10.99 106 223 3.113

-13 9 363.3 27 81 50.28 67 153 10.61 107 225 3.025

-12 10 343.6 28 82 48.14 68 154 10.25 108 226 2.941

-11 12 325.1 29 84 46.11 69 156 9.902 109 228 2.86

-10 14 307.7 30 86 44.17 70 158 9.569 110 230 2.781

-9 16 291.3 31 88 42.33 71 160 9.248 111 232 2.704

-8 18 275.9 32 90 40.57 72 162 8.94 112 234 2.63

-7 19 261.4 33 91 38.89 73 163 8.643 113 235 2.559

-6 21 247.8 34 93 37.3 74 165 8.358 114 237 2.489

-5 23 234.9 35 95 35.78 75 167 8.084 115 239 2.422

-4 25 222.8 36 97 34.32 76 169 7.82 116 241 2.357

-3 27 211.4 37 99 32.94 77 171 7.566 117 243 2.294

-2 28 200.7 38 100 31.62 78 172 7.321 118 244 2.233

-1 30 190.5 39 102 30.36 79 174 7.086 119 246 2.174

0 32 180.9 40 104 29.15 80 176 6.859 120 248 2.117

1 34 171.9 41 106 28 81 178 6.641 121 250 2.061

2 36 163.3 42 108 26.9 82 180 6.43 122 252 2.007

3 37 155.2 43 109 25.86 83 181 6.228 123 253 1.955

4 39 147.6 44 111 24.85 84 183 6.033 124 255 1.905

5 41 140.4 45 113 23.89 85 185 5.844 125 257 1.856

6 43 133.5 46 115 22.89 86 187 5.663 126 259 1.808

7 45 127.1 47 117 22.1 87 189 5.488 127 261 1.762

8 46 121 48 118 21.26 88 190 5.32 128 262 1.171

9 48 115.2 49 120 20.46 89 192 5.157 129 264 1.674

10 50 109.8 50 122 19.69 90 194 5 130 266 1.632

11 52 104.6 51 124 18.96 91 196 4.849

12 54 99.69 52 126 18.26 92 198 4.703

13 55 95.05 53 127 17.58 93 199 4.562

14 57 90.66 54 129 16.94 94 201 4.426

15 59 86.49 55 131 16.32 95 203 4.294

16 61 82.54 56 133 15.73 96 205 4.167

17 63 78.79 57 135 15.16 97 207 4.045

18 64 75.24 58 136 14.62 98 208 3.927

19 66 71.86 59 138 14.09 99 210 3.812

TemperatureSensorResistanceValueTable(°C-K)

TEMPERATURE SENSOR RESISTANCE TABLE

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OtherTemperatureSensorResistanceValueTable(°C-K)

°C °F K Ohm °C °F K Ohm °C °F K Ohm °C °F K Ohm

-20 -4 115.266 20 68 12.6431 60 140 2.35774 100 212 0.62973

-19 -2 108.146 21 70 12.0561 61 142 2.27249 101 214 0.61148

-18 0 101.517 22 72 11.5 62 144 2.19073 102 216 0.59386

-17 1 96.3423 23 73 10.9731 63 145 2.11241 103 217 0.57683

-16 3 89.5865 24 75 10.4736 64 147 2.03732 104 219 0.56038

-15 5 84.219 25 77 10 65 149 1.96532 105 221 0.54448

-14 7 79.311 26 79 9.55074 66 151 1.89627 106 223 0.52912

-13 9 74.536 27 81 9.12445 67 153 1.89627 107 225 0.51426

-12 10 70.1698 28 82 8.71983 68 154 1.83003 108 226 0.49989

-11 12 66.0898 29 84 8.3356 69 156 1.76647 109 228 0.486

-10 14 62.2756 30 86 7.97078 70 158 1.70547 110 230 0.47256

-9 16 58.7079 31 88 7.62411 71 160 1.64691 111 232 0.45957

-8 18 56.3694 32 90 7.29464 72 162 1.59068 112 234 0.44699

-7 19 52.2438 33 91 6.98142 73 163 1.53668 113 235 0.43482

-6 21 49.3161 34 93 6.68355 74 165 1.48481 114 237 0.42304

-5 23 46.5725 35 95 6.40021 75 167 1.43498 115 239 0.41164

-4 25 44 36 97 6.13059 76 169 1.38703 116 241 0.4006

-3 27 41.5878 37 99 5.87359 77 171 1.34105 117 243 0.38991

-2 28 39.8239 38 100 5.62961 78 172 1.29078 118 244 0.37956

-1 30 37.1988 39 102 5.3689 79 174 1.25423 119 246 0.36954

0 32 35.2024 40 104 5.17519 80 176 1.2133 120 248 0.35982

1 34 33.3269 41 106 4.96392 81 178 1.17393 121 250 0.35042

2 36 31.5635 42 108 4.76253 82 180 1.13604 122 252 0.3413

3 37 29.9058 43 109 4.5705 83 181 1.09958 123 253 0.33246

4 39 28.3459 44 111 4.38736 84 183 1.06448 124 255 0.3239

5 41 26.8778 45 113 4.21263 85 185 1.03069 125 257 0.31559

6 43 25.4954 46 115 4.04589 86 187 0.99815 126 259 0.30754

7 45 24.1932 47 117 3.88673 87 189 0.96681 127 261 0.29974

8 46 22.5662 48 118 3.73476 88 190 0.93662 128 262 0.29216

9 48 21.8094 49 120 3.58962 89 192 0.90753 129 264 0.28482

10 50 20.7184 50 122 3.45097 90 194 0.8795 130 266 0.2777

11 52 19.6891 51 124 3.31847 91 196 0.85248 131 268 0.27078

12 54 18.7177 52 126 3.19183 92 198 0.82643 132 270 0.26408

13 55 17.8005 53 127 3.07075 93 199 0.80132 133 271 0.25757

14 57 16.9341 54 129 2.95896 94 201 0.77709 134 273 0.25125

15 59 16.1156 55 131 2.84421 95 203 0.7537 135 275 0.24512

16 61 15.3418 56 133 2.73823 96 205 0.73119 136 277 0.23916

17 63 14.6181 57 135 2.63682 97 207 0.68844 137 279 0.23338

18 64 13.918 58 136 2.53973 98 208 0.66818 138 280 0.22776

19 66 13.2631 59 138 2.4467 99 210 0.64862 139 282 0.22231

TEMPERATURE SENSOR RESISTANCE TABLE

mrcool.com83

Pressure Temperature Pressure Temperature

Kpa Bar PSI °C °F Kpa Bar PSI °C °F

58.196 0.58 8.44 -60 -76 935.23 9.35 135.64 8 46.4

61.517 0.62 8.92 -59 -74.2 963.75 9.64 139.78 9 48.2

64.988 0.65 9.43 -58 -72.4 992.93 9.93 14401 10 50

68.615 0.69 9.95 -57 -70.6 1022.8 10.23 148.34 11 51.8

72.402 .072 10.50 -56 -68.8 1053.3 10.53 152.76 12 53.6

76.354 0.76 11.07 -55 -67 1084.5 10.85 157.29 13 55.4

80.478 0.80 11.67 -54 -65.2 1116.4 11.16 161.91 14 57.2

84.776 0.85 12.30 -53 -63.4 1149 11.49 166.64 15 59

89.256 0.89 12.95 -52 -61.6 1182.3 11.82 171.47 16 60.8

93.923 0.94 13.62 -51 -59.8 1216.3 12.16 176.40 17 62.6

98.781 0.99 14.33 -50 -58 1251.1 12.51 181.45 18 64.4

103.84 1.04 15.06 -49 -56.2 1286.6 12.87 186.60 19 66.2

109.1 1.09 15.82 -48 -54.4 1322.8 13.23 191.85 20 68

114.56 1.15 16.61 -47 -52.6 1359.9 13.60 197.23 21 69.8

120.25 1.20 17.44 -46 -50.8 1397.7 13.98 202.71 22 71.6

126.15 1.26 18.30 -45 -49 1436.3 14.36 208.31 23 73.4

132.28 1.32 19.18 -44 -47.2 1475.7 14.76 214.02 24 75.2

138.64 1.39 20.11 -43 -45.4 1515.9 15.16 219.85 25 77

145.24 1.45 21.06 -42 -43.6 1557 15.57 225.82 26 78.8

152.09 1.52 22.06 -41 -41.8 1598.9 15.99 231.89 27 80.6

159.18 1.59 23.09 -40 -40 1641.6 16.42 238.09 28 82.4

166.54 1.67 24.15 -39 -38.2 1685.2 16.85 244.41 29 84.2

174.15 1.74 25.26 -38 -36.4 1729.7 17.30 250.86 30 86

182.04 1.82 26.40 -37 -34.6 1775 17.75 257.43 31 87.8

190.2 1.90 27.59 -36 -32.8 1821.3 18.21 264.15 32 89.6

198.65 1.99 28.81 -35 -31 1868.4 18.68 270.98 33 91.4

207.39 2.07 30.08 -34 -29.2 1916.5 19.17 277.95 34 93.2

216.42 2.16 31.39 -33 -27.4 1965.6 19.66 285.08 35 95

225.76 2.26 32.74 -32 -25.6 2015.5 20.16 292.31 36 96.8

235.41 2.35 34.14 -31 -23.8 2066.5 20.67 299.71 37 98.6

245.37 2.45 35.59 -30 -22 2118.4 21.18 307.24 38 100.4

255.67 2.56 37.08 -29 -20.2 2171.3 21.71 314.19 39 102.2

266.29 2.66 38.62 -28 -18.4 2225.2 22.25 322.73 40 104

277.25 2.77 40.21 -27 -16.6 2280.2 22.80 330.70 41 105.8

288.56 2.89 41.85 -26 -14.8 2336.1 23.36 38.81 42 107.6

300.22 3.00 43.54 -25 -13 2393.2 23.93 347.09 43 109.4

312.24 3.12 45.28 -24 -11.2 2451.3 24.51 355.52 44 111.2

324.63 3.25 47.08 -23 -9.4 2510.4 25.10 364.09 45 113

337.39 3.37 48.93 -22 -7.6 2570.7 25.71 372.84 46 114.8

350.54 3.51 50.84 -21 -5.8 2632.1 26.32 381.74 47 116.6

364.08 3.64 52.80 -20 -4 2694.7 26.95 390.82 48 118.4

378.02 3.78 54.83 -19 -2.2 2758.33 27.58 400.04 49 120.2

392.37 3.92 56.91 -18 -0.4 2823.2 28.23 409.46 50 122

407.13 4.07 59.05 -17 1.4 2889.3 28.89 419.04 51 123.8

System Pressure Table-R454B

SYSTEM PRESSURE TABLE

mrcool.com 84

Pressure Temperature Pressure Temperature

Kpa Bar PSI °C °F Kpa Bar PSI °C °F

422.31 4.22 61.25 -16 3.2 2956.5 29.57 428.79 52 125.6

437.92 4.38 63.5 -15 5 3025 30.25 438.72 53 127.4

453.98 4.54 65.84 -14 6.8 3094.7 30.95 448.83 54 129.2

470.47 4.70 68.23 -13 8.6 3165.7 31.66 459.13 55 131

487.43 4.87 70.69 -12 10.4 3238.1 32.38 469.63 56 132.8

504.84 5.05 73.22 -11 12.2 3311.7 33.12 480.30 57 134.6

522.73 5.23 75.81 -10 14 3386.7 33.87 491.18 58 136.4

541.1 5.41 78.48 -9 15.8 3463 34.63 502.25 59 138.2

559.95 5.60 81.21 -8 17.6 3540.7 35.41 513.52 60 140

579.31 5.79 84.02 -7 19.4 3619.9 36.20 525.00 61 141.8

599.16 5.99 86.90 -6 21.2 3700.5 37.01 536.69 62 143.6

619.54 6.20 89.85 -5 23 3782.7 37.83 548.61 63 145.4

640.43 6.40 92.88 -4 24.8 3866.3 38.66 560.74 64 147.2

661.86 6.62 95.99 -3 26.6 3951.5 39.52 573.10 65 149

683.82 6.84 99.18 -2 28.4 4038.3 40.38 585.69 66 450.28

706.34 7.06 102.44 -1 30.2 4126.8 41.27 598.52 67 152.6

729.41 7.29 105.79 0 32 4217 42.17 611.60 68 154.4

753.06 7.53 109.22 1 33.8 4309 43.09 624.95 69 156.2

777.28 7.77 112.73 2 35.6 4402.9 44.03 638.56 70 158

802.08 8.02 116.33 3 37.4 4498.7 44.99 652.46 71 159.8

827.47 8.27 120.01 4 39.2 4596.5 45.97 666.64 72 161.6

853.49 8.53 123.78 5 41 4696.5 46.97 681.15 73 163.4

880.11 8.80 127.64 6 42.8 4798.9 47.99 696.00 74 165.5

907.35 9.07 131.60 7 44.6 4904.1 49.04 711.25 75 167

System Pressure Table-R454B Cont.

SYSTEM PRESSURE TABLE

Olympus Series

Cassette

Air Handler

Service Manual

The design and specications of this product and/or manual are subject to change without prior notice.

Consult with the sales agency or manufacturer for details.

Mrcool CASSETTE18HP230CPO Olympus Ceiling Cassette Indoor Unit with 18000 BTU Capacity, Heat Pump, and 230 Volts in White Outdoor Unit Required to Operate

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Service Manual.

Specifications

Mrcool CASSETTE18HP230CPO Questions and Answers

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