MrCool Universal Series, MDUI180 E Series Manual

To Our Customers;
Please read this manual carefully before installation and operation of the Universal™ Series High ESP Air Handler to ensure correct use and handling. In addition to the safety precautions in the previous section, please adhere to the following guidelines and note our exceptions to liability.

1. This appliance can be used by children aged 8 years and older and persons with reduced physical, sensory or mental capabilities or lack of experience and knowledge if they have been given supervision or instruction concerning use of the appliance in a safe way and understand the hazards involved. Children should not play with the appliance. Cleaning and user maintenance should not be performed by children.
2. To ensure product reliability, the unit may consume power under stand-by status to maintain normal communication, and for preheating refrigerant and lubricant. If the unit will not be used for an extended period, disconnect the power supply. Reconnect the power supply and preheat the unit prior to use.
3. Ensure you have selected the proper model for the operating environment. Improper selection may impact operating performance.
4. This product has undergone strict inspection and operational testing before leaving the factory. To avoid damage due to improper disassembly, which may impact the normal operation, please do not disassemble the unit without proper training and equipment.
5. For technical assistance, please contact MRCOOL^® technical support at (270) 366-0457.
6. If the product is malfunctioning and/or is inoperable, please contact MRCOOL^® technical support at the aforementioned number, as soon as possible and provide the following information:
   1. Product Nameplate Contents (model number, cooling / heating capacity, product serial number, factory date)
   2. Nature of Malfunction (specify the circumstances before and after the error occurred)
7. All illustrations and information in the instruction manual are for reference only. In order to improve the product, we will continuously assess and innovate. We retain the right to make necessary revisions to the product from time to time. We reserve the right to revise the contents of this manual without notice.
8. If the supply cord is damaged, it must be replaced by MRCOOL^®, a professional service agent, or a similarly qualified person in order to avoid damage to the product.
9. MRCOOL^®, LLC assumes no responsibility for personal injury, property loss or equipment damage caused by improper installation and commissioning, unnecessary maintenance, or failure to follow relevant federal and state regulations, industrial standards, and the requirements of this instruction manual.
10. MRCOOL^®, LLC will bear no responsibilities for personal injury or property damage caused by the following:
    1. Improper use of the appliance
    2. Altering, maintaining, or operating the product with non-approved equipment
    3. Altering, maintaining, or operating the product outside of the guidelines of this manual
    4. Defects caused by corrosive gas
    5. Defects caused by shipping damage
    6. Failure to abide by this instruction manual or government regulations
    7. Products made by other manufacturers
    8. Natural disasters, improper installation environment, or force majeure

The Universal Series^® High ESP Air Handler offers the perfect combination of superior product quality, operating efficiency, operating sound levels, and value for money. The condensing unit uses the environmentally friendly refrigerant R-410A, which is chlorine-free to help prevent damage to the ozone layer.
Unless otherwise stated (as "OPTIONAL"), the air conditioning system includes the accessories listed below. Use all of the installation parts and accessories to install the air conditioner. Improper installation may result in water leakage, electrical shock, fire, and/or equipment failure.

Accessories

	Additional Line Sets & Coupler Kit
	If you find the standard size NO-VAC® QUICK CONNECT® LINE SET* length is not sufficient for your application, additional line sets are available for purchase. You will also need a NO-VAC® COUPLER kit (pictured), which allows line sets to be connected together to increase the length. The coupler kit is installed and checked for leaks by following the same steps described in this manual for connecting the line set to the indoor air handler (Refer to the NO-VAC® QUICK CONNECT® Line Set section on for these steps).
NO-VAC® QUICK CONNECT® LINE SET Lengths Available	15 FT	25 FT	35 FT	50 FT

Unit Dimensions
MDUI18024E/MDUI18036E &
MDUI18048E/MDUI18060E

Unit Dimensions: Inches (mm)

Main Parts

Unit: inch (mm)

NOTE

1. Dry coil and filter should be installed based upon nominal tonnage.
2. Use 0.96 as approximate SCFM correction factor for wet coil (optional).

Unit Installation

The Universal™ Series Has 2 Installation Methods

1. The Conventional Weld Line Set Installation Instructions
   OR
   View complete install video by scanning this QR code
   
2. No-Vac ® Quick Connect ® Line Set* Installation Instructions
   OR
   View complete install video by scanning this QR code
   

• Before servicing or installing this equipment, the electrical power to this unit must be in the "OFF" position.
• More than one electrical disconnect may exist on this unit. Lock out and tag the switch with a suitable warning label. Failure to observe this warning may result in electrical shock that can cause personal injury or death.
• Due to high system pressure and the potential for electrical shock, installation and service work can be dangerous. Only trained and qualified persons are permitted to install or service this equipment. Observe all warnings contained in this manual and labels/tags attached to the equipment.

1. Checking Product Received
   After receiving the product, please check for any damage caused by transportation. Shipping damage is the responsibility of the carrier. Verify the model number, specifications, and accessories are correct prior to installation. The distributor or manufacturer will not accept claims from dealers for transportation damage or installation of incorrectly shipped units. If an incorrect unit is supplied, it must not be installed and it is to be returned to the supplier. The manufacturer assumes no responsibility for the installation of incorrectly delivered units.
2. Before Installation
   Carefully read all instructions for the installation prior to installing product. Make sure each step or procedure is understood and any special considerations are taken into account before starting installation. Assemble all tools, hardware and supplies needed to complete the installation. Some items or tools may need to be purchased separately.
   NOTE: Make sure everything needed to install the product is on hand before starting.
3. Codes & Regulations
   This product is designed and manufactured to comply with national codes. It is the installer's responsibility to install the product in accordance with such codes and/or any prevailing local codes/regulations. The manufacturer assumes no responsibilities for equipment installed in violation of any codes or regulations.
4. Replacement Parts
   When reporting shortages, damages, or ordering repair parts, be sure to give the complete product model and serial numbers as stamped on the product. Replacement parts for this product are available through your contractor or local distributor.
   NOTE: In the event the main board of the unit needs to be replaced, the technician should install the jumper cap and short-driven electrical resistance from the old board onto the new board. If there is no shortdriven resistance on the old board then it does not need to be replaced on the new board.

Installation Location

• When installing the air handler, attempt to minimize the length of refrigerant tubing needed as much as possible.
• When installing in an area directly over a finished ceiling (such as an attic), installation of an emergency drain pan is required directly under the unit. See local and state codes for requirements.
• When installing this unit in an area that may become wet, elevate the unit with a sturdy, non-porous material. In installations that may lead to physical damage (i.e. a garage), it is advised to install a protective barrier to prevent such damage.
  DO NOT install this unit outdoors. This air handler is designed for indoor installation only.
  DO NOT operate this product without complete ductwork attached. This air handler is designed for a complete supply and return ductwork system.
  DO NOT install the air handler in a location above or below the condenser that violates the instructions provided with the condenser. Service clearance is to take precedence. Allow a minimum of 24 in (610 mm) service clearance in front of the unit.
  DO NOT install the air handler in enclosed areas, such as garages, utility rooms or parking areas. Carbon monoxide producing devices (such as an automobile, space heater, gas water heater, etc.) should not be operated in enclosed areas such as unventilated garages, utility rooms, or parking areas because of the danger of carbon monoxide (CO) poisoning resulting from exhaust emissions. If a furnace or air handler is installed in an enclosed area such as a garage, utility room, or parking area, and a carbon monoxide producing device is operated therein, there must be direct ventilation to the outside. Adequate ventilation is necessary to avoid the danger of CO poisoning which can occur if a carbon monoxide producing device continues to operate in an enclosed area. If these warnings are not followed, carbon monoxide emission can be (re)circulated throughout the building from the air handler causing serious illness including permanent brain damage or death.
• If air handler is installed as shown in Fig. 2.1, the air handler should be concealed in a specific room or space and make sure the air handler is not accessible to the general public.
  
• If air handler is installed as shown in Fig. 2.2, make sure there is enough space for care and maintenance, and that the height between the air handler and ground is above 8 ft (2500 mm). Also make sure the air handler is not accessible to the general public.
  

Unit Installation - OPTION 1: Conventional Weld / Flare Line Set

Conventional Line Set Installation
Specification of Connection Pipe

In order to prevent the refrigerant piping from sweating, you can insulate them with closed-cell insulation foam for refrigerant line sets which is readily available.

Piping Preparation

1. WELD Type Complete Unit Replacement
   All cut ends are to be round, clean, and burr free. Failure to follow this practice increases the chances for refrigerant leakage. Ensure that the line set size matches service valve connection.
   DO NOT crimp the service valve connector when the pipe is smaller than the connector. See diagram below.
   

No-Vac^® Quick Connect^® Line Set* Installation

INSTRUCTIONS FOR USE WITHNO-VAC™ QUICK CONNECT® LINE SET*
SOLD SEPARATELY KINK RESISTANT, PRECHARGED, SIMPLE SECURE QUICK CONNECT, 100% CONNECTION GUARANTEE
Please read and follow the instrucons and diagram below^* :
Connecons must be made exactly as specified to avoid system leaks and /or damage

When running the Line Set through the knockout hole of the condenser, it may be necessary to slightly trim the line set insulation so it feeds through the hole freely. Otherwise, it may be difficult to connect it to the condenser. Once the installation is complete, pack the hole with neoprene to prevent small animals and insects from entering the condenser.

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

The stop/cutoff valves on the unit must be opened AFTER connecting the lines and BEFORE turning on the unit. Otherwise, operation can cause leakage and/ or damage to the unit.

1. Take out matching male connectors M1 and M2.
2. Remove protecve cap with the copper gasket at each stop valve on the CONDENSER and ensure the threads are clean and complete.
3. Tighten the M1 connector to the cutoff valve *1 with a ghtening force of 37 /lb (50 Nm). Tighten the M2 connector to the cutoff valve *2 with a ghtening force of 52 /lb (70 Nm).
4. Repeat step 3 for AIR HANDLER at the other end of the LINE SET.
5. Unroll and route theLINE SET between the AIR HANDLER and the CONDENSER. Bend the line set piping by hand to route the line set to suit your applicaon. Use care when bending the line set. Please refer to the Bending the Line Set secon ofPg. 13 for more detailed instrucons on how to properly and safely bend the line set refrigerant piping, as well as the correct bend radius.
6. Remove the protecve caps of the valves at both ends of the LINE SET. Verify that all threads are clean and complete.

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

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

ⱡFailure to follow the instructions provided could result in severe harm to you, this product, or other property.
The manufacturer, distributor, and seller are not responsible for any harm resulting from the failure to follow instructions and the failure to follow these instructions will void any and all warranties express or implied.

Bending the Line Set

1. Use your hands to bend the pipes. Work carefully not to collapse the pipes during bending.
2. If the pipe is repeatedly bent or extended, it will become hard and difficult to manipulate. Avoid bending or extending the pipe more than 3 times.
   DO NOT bend the pipes in at an angle greater than 90°.
   DO NOT bend the pipe excessively, otherwise it will break.
   Please refer to Fig. 2.7
   
3. As shown in Fig. 2.8, use a sharp cutter to cut the pipe insulation and bend the pipe after it is exposed. After bending, place the insulation back on the pipe and secure it with adhesive tape.
   

Condensate Removal

1. The condensate drain pipe should be connected into a special drain system for the unit.
2. The drain pan has primary and secondary drain connections. Condensate removal is performed by attaching a 3/4 in (19 mm) PVC pipe to the evaporator coil pan and terminated in accordance with local or state plumbing and HVAC codes. The installation must include a "P" style trap that is located closely to the evaporator coil.
   
   DO NOT over-tighten the drain connection in order to prevent damage to the evaporator drain pan. See the following figure for details of a typical condensate line "P" trap.
   DO NOT connect the condensate drain pipe into the waste pipe or other pipelines that are likely to produce corrosive or peculiar smells. This will prevent odors from entering indoors or corrupting the unit.
   DO NOT connect the condensate drain pipe into the rain pipe. This will prevent rain water from pouring in and causing property loss or personal injury.
   

Ductwork
This air handler is designed for a complete supply and return ductwork system.

DO NOT operate the unit without all ductwork completed and attached.

• Inadequate ductwork that restricts airflow can result in improper performance and could cause compressor or heater failure.
• Ductwork is to be constructed in a manner that limits restrictions and maintains suitable air velocity.
• Ductwork is to be sealed to the unit in a manner that will prevent leakage.

Return ductwork:
DO NOT dispose of the return ductwork in an area that can introduce toxic or objectionable fumes/odors into the ductwork. The return ductwork is to be introduced into the air handler bottom (upflow configuration).

Return Air Filters:
Each installation must include a return air filter for the air handler or externally using a return air filter grille.

Electric Heater
The air handlers listed in this manual do not have a factory installed electric heater. An electric heat kit is available as an optional accessory. The only heat kits that can be used are MHK**U series listed on the following page. Please refer to installation instructions provided with the heat kit for the correct installation procedure.

The electrical characteristics of the air handler, the electric heat kit, and the supply power should be identical.

Electric Heat Kit Installation

• Ensure that the power supply is disconnected prior to installing the heat kit.
• A means of strain relief and conductor protection must be provided at the supply wire entrance into the cabinet.
• Only use copper conductors.
• Installation must follow National Electric Code (NEC) and other applicable codes.
• If this appliance is installed in an enclosed area such as a garage or utility room with any carbon monoxide producing appliance, ensure the area is properly ventilated to the outside.
• A filter dryer is recommended for installation based on nominal tonnage.
• Use 0.96 as approximate SCFM correction factor for wet coil.

1. Refer to the Table below for the appropriate optional heat kit.
2. Check for any physical damage; do not install a damaged heat kit.
3. Remove the upper access panel from air handler.
4. Remove the cover plate from air handler.
5. Slide the heat kit into the slot and secure element plate with previously removed screws.
6. Insert power leads into the circuit breaker lugs or stripped red and black wires (for heat kits without a circuit breaker) and tighten.
7. Connect ground wire to ground lug.

8. Break out appropriate area of the plastic circuit breaker cover on the access panel of the air handler. Knock out the holes according to the actual installation number and circuit breaker positions. If a circuit breaker is not installed, do not knock out the holes; otherwise, electric shock may occur.
9. Connect power cords and thermostat wires.
10. Replace access panel and check operation.

Compatible Heat Kits

You must use a compatible heat kit listed in the above chart. Using an incorrectly sized heat kit could cause the unit to overheat and/or equipment damage.

Dip Switch Configuration
Set the indoor fan speed through the eight dip switches of the indoor main control board. The higher the level, the higher the speed of the indoor unit fan. Operation Instruction is below:
Dip switch settings must be completed before power on the unit.
After the unit is shut down or stopped at the temperature point, the indoor unit will delay for a few minutes and then shut down. The refrigeration can realize the drying function, relieve the mold of the air duct, and the heating can blow the waste heat and relieve the heat accumulation in the air duct.
During installation and debugging, pay attention to check whether the temperature controller has set the fan delay and shutdown time. If the temperature controller has been set, the actual delay and shutdown time of the fan is equal to the temperature controller setting time plus the fan delay time of the indoor unit.

NOTE: 0 means dip switch to 'on', 1 means dip switch to number.

Fan Performance Data
External static pressure should stay within the minimum and maximum limits shown in the table below in order to ensure proper operation of both cooling, heating, and electric heating operation.

NOTE: Please refer to above table for fan speed selection, and '-' indicates that the electric heater is not allowed to be used.

Electrical Regulations

Before performing electrical work, read the following regulations
DO NOT change the power cables arbitrarily.
DO NOT change the length and terminals of the power cables.

1. Electrical installation must be conducted by professionals in compliance with local laws, regulations, and this installation manual. Never artificially extend the length of a power cord. The electric circuit must be equipped with a circuit breaker and air switch. Both must have sufficient capacity.
2. Unit operating power must be within the nominal range stated in the instruction manual. Use a specialized power circuit for the unit. DO NOT draw power from another power circuit.
3. The air conditioner circuit should be at least 5 ft (1.5 m) away from any flammable surface.
4. The external power cords, the thermostat wires, and thermostat must be effectively fixed.
5. The external power cords, thermostat wires, and thermostat must NOT directly contact any hot objects. For example: they must not come into contact with chimney pipes, warm gas pipes or other hot objects.
6. The external power cords, thermostat wires, and thermostat must NOT be squeezed. Never pull, stretch, or bend the wires.
7. The external power cords, thermostat wires, and thermostat must NOT collide with any metal beam or edge on the ceiling, or touch any metal burrs or sharp metal edges.
8. Connect wires in accordance to the circuit diagram labeled on the unit or electric box. Screws must be tightened. Slipped screws must be replaced by specialized flat-head screws.
9. Wiring terminals should be connected securely to the terminal board. A loose connection is unsafe.
10. Only use the power cables that are delivered with the air conditioner. If you want to change the power cables, please contact MRCOOL's local service center.
11. After the electrical installation is finished, please use wire clamps to secure the power cords and thermostat wires. Make sure the wires are not clamped too tightly.
12. The wire gauge of the power cord should be sufficiently large. A damaged power cord or other wires must be replaced by specialized wires. Wiring must be completed according to national wiring rules and regulations.
13. This product is factory shipped for use with a 208/230V-1Ph-60Hz electrical power supply. This air handler must not be reconfigured to operate with any other power supply.
14. The unit must have uninterrupted and unbroken electric grounding to minimize the possibility of personal injury if an electric fault occurs. The electric grounding circuit may consist of an appropriate sized power cord connected with the grounding piece, located in the unit control box, and also connecting to the building electric service panel. Other methods of grounding are permitted if performed in accordance with the National Electric Code (NEC), American National Standards Institute (ANSI), National Fire Protection Association (NFPA) 70, and local/state codes. In Canada, electric grounding conforms to the Canadian electric code CSA c22.1. Failure to observe this warning can result in electrical shock that can cause personal injury.

***Disclaimer: Wiring must meet code specs according to the capacity/tonnage of the unit.***

1. The fuse is located on the main board.
2. Install a circuit breaker at every power terminal near the units (indoor unit and thermostat) with at least 0.12 in (3 mm) contact gap. Both units must reach the plug.
3. Circuit breaker and power cord specifications listed in the above table are determined based on the maximum power input of the units.
4. Specifications of power cords listed in the above table are applicable in a working condition where the ambient temperature is 104°F (40°C) and multi-core copper cable (e.g. YJV copper cable, with insulated PE and PVC sheath) is protected by a conduit, and is resistant to 194°F (90°C) in maximum (see IEC 60364-5-52). If working conditions change, please adjust the specifications according to national standards.
5. Specifications of circuit breaker are based on a working condition where the working temperature is 104°F (40°C). If working conditions change, please adjust the specifications according to national standards.
6. The gauge of thermostat wire between the indoor unit and thermostat should be no less than 18 AWG and at least 6 strand to ensure a proper connection. Please select a proper length of wire according to local conditions. The maximum connection length is 98 feet (30 m).
7. Thermostat wires must not be twisted together.

Connecting the Power Cord & Communication Wire

Connecting the Power Cord & Thermostat Wires
For solid wires (Refer to Fig. 2.14 A):

1. Use wire cutters to cut off the wire end and then peel away about 1 in (25 mm) of the insulation layer.
2. Use a screwdriver to unscrew the terminal screw on the terminal board.
3. Use needle nose pliers to bend the solid wire into a ring that fits the terminal screw.
4. Form a proper ring and attach to the terminal board. Use a screwdriver to tighten the terminal screw.

For braided/strand wires (Refer to Fig. 2.14 B & Fig. 2.15):

1. Use wire cutters to cut off the wire end and then peel away about 3/8 in (10 mm) of the insulation layer.
2. Use a screwdriver to unscrew the terminal screw on the terminal board.
3. Use a round terminal fastener or clamp to secure the round terminal firmly on the peeled wire end.
4. Locate the round terminal conduit. Use a screwdriver to replace it and tighten the terminal screw (as shown in Fig. 2.15).
   

For all terminal wiring (Refer to Fig. 2.17 (2-3 ton unit) below, Fig. 2.18 (4-5 ton unit):

5. Lead the connection wire and power cord through the insulation tube. Then secure the wires with wire clamps (as shown in Fig. 2.16).
   

1. Remove the upper access panel from the air handler.
2. Remove the cover plate inside the upper access panel of the air handler.
3. Slide the heat kit into the slot and secure element plate with previously removed screws.
4. Make sure to insert the supporting poles of the heat kit into the supporting hole of the air handler.
5. Connect the quick connection plug and fasten the loose wires by using wire ties.
6. Install the circuit breaker into the mounting rail, break out appropriate area of the plastic circuit breaker cover on the access panel of the air handler.
7. 1. When installing the MHK05U, MHK08U, or MHK10U, connect the power from the Circuit Breaker Panel to L1 and L2 of the circuit breaker included with the electric heat kit.
   2. When connecting the electric heat kit to the air handler, use the Molex Plug Wiring Harness from the electric heat kit and attach it to the Molex Plug Wiring Harness coming from air handler's PCB board.
   3. The Molex Plug Connection will power the air handler, so a separate source of incoming power for the air handler itself is not needed.
   4. Please see the chart below for proper sizing of panel.

1. High and low voltage wires should be led through different rubber rings of the electric box cover.
2. Do not bundle up the thermostat wires or lay them side by side, otherwise errors will occur.
3. High and low voltage wires should be secured separately. Secure the former ones with big clamps and the latter ones with small clamps.
4. Use screws to tighten up the thermostat wires and power cords of unit on the terminal board. Wrong connection may lead to fire hazard.
5. If the thermostat wires of unit and power cords are not correctly connected, the air conditioner may get damaged.
6. Ground the unit through connecting the ground wire.
7. The units should comply with applicable local and national rules and regulations on power consumption.
8. When connecting the power cords, make sure the phase sequence of the power supply matches with the corresponding terminals, otherwise the compressor will get reversed and operate abnormally.
9. Power cord must be connected firmly and the resistance at the connection position can't be more than 0.1Ω; otherwise, it may cause a safety accident.

Electrical wiring of Single-phase unit: MDUI18048E/MDUI18060E (4-5 Ton Unit w/electric heater)
Optional: Heat Kit Installation Instructions

1. Remove the upper access panel from the air handler.
2. Remove the cover plate inside the upper access panel of the air handler.
3. Slide the heat kit into the slot and secure element plate with previously removed screws.
4. Make sure to insert the supporting poles of the heat kit into the supporting hole of the air handler.
5. Connect the quick connection plug and fasten the loose wires by using wire ties.
6. Install the circuit breaker into the mounting rail, break out appropriate area of the plastic circuit breaker cover on the air handler access panel.
7. 1. When installing the MHK15U or MHK20U, connect two separate lines of power from the Circuit Breaker Panel to L1 and L2 of the two circuit breakers included with the electric heat kit.
   2. When connecting the electric heat kit to the air handler, use the Molex Plug Wiring Harness from the electric heat kit and attach it to the Molex Plug Wiring Harness coming from air handlers PCB board.
   3. The Molex Plug Connection will power the air handler, so a separate source of incoming power for the air handler itself is not needed.
   4. Please see the chart below for proper sizing of panel.

Post Installation Checks

Before Test Run
Only perform test run AFTER you have completed the following steps:

• Electrical Safety Checks – Confirm that the electrical system is safe and operating properly.
• Gas Leak Checks – Check all refrigerant piping connections/valves and confirm that the system is not leaking.
• Confirm that gas and liquid (high and low pressure) valves are fully open.

Test Run
Preparation Before Connecting The Power:
DO NOT connect power if the installation is not complete.

1. Verify the control circuit is correct and all the wires are firmly and securely connected.
2. Ensure the valves on the vapor and liquid refrigerant lines are completely opened.
3. Remove any scattered objects or debris around the unit, especially metal filings, thrum, and clippings.
4. Ensure the unit's appearance and piping system have not been damaged during transportation or handling.
5. Check for any loose terminals and ensure the phases are correct.

Operation After Connecting The Power:

1. If all the steps above have been completed, power on the unit.
2. Verify the unit functions properly under several of its different operating modes.
3. If there are any loud and/or abnormal sounds, turn off the unit and contact MRCOOL^® Tech Support, at (270) 366-0457, immediately.

Troubleshooting

If your air conditioner fails to function normally, check the following items before conducting maintenance:

NOTICE
Check the above items and take appropriate corrective measures. If the unit continues to function improperly, immediately disconnect power and contact the MRCOOL® technical department, at (270) 366-0457, or your installation dealer.

The following situations are not operation failures.

Error Code

• When abnormalities occur, stop the unit immediately and disconnect power. Contact the MRCOOL^® technical department at the number below. If the unit continues to run abnormally, it may damage the unit and cause an electric shock and/or a fire hazard.
  DO NOT attempt repairs to the appliance yourself. Improper repair and maintenance can create electric shock and fire hazards. Please contact MRCOOL^® Tech Support, at (270) 366-0457, for further guidance or a qualified professional for repairs.

If the display panel or wired control displays an error code, please refer to the table on the following page.

Error Code
If the display panel or wired control displays an error code, please refer to the following table:

NOTICE
When the unit is connected with the wired controller, the error code will show simultaneously on it.

Maintenance and Care

Regular checks, maintenance, and care should be performed by professional personnel, which will prolong the life span of the unit.

Drain Pipe
Regularly check the drain pipe for leaks and clogs in order to ensure smooth condensate drainage.

Notice Before Seasonal Use

1. Check the inlet/outlet of the indoor unit and ensure it is not clogged.
2. Check the ground wire and ensure it is securely connected.
3. Check if the filter screen has been installed correctly.
4. Check and ensure the unit is installed firmly and securely.
5. If there is something abnormal, please contact the local appointed service center.

Maintenance After Seasonal Use

1. Cut off the main power supply of the unit.
2. Clean the filter screen of indoor units.
3. Clean the dust from the indoor units.
4. In the event of rust and corrosion, use anti-rust paint to stop it from continuing to spread.

Parts Replacement
Purchase replacement parts from local appointed service center or dealer if necessary.

After-Sales Service
If the air-conditioning unit you purchased has any quality problem or you have any inquiry, please contact the MRCOOL^® Tech Support, at (270) 366-0457.

Safety Precautions

Read Before Installation
Incorrect installation may cause serious damage or injury.
The seriousness of potential damage or injuries is classified as either a WARNING or CAUTION.

This symbol indicates that ignoring instructions may cause moderate personal injury, damage to your unit, or other property.

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

Please read the manual in its entirety before installing, operating or repairing.
DO NOT connect other appliances to the same circuit. You must use an independent circuit to supply power. Insufficient electrical capacity or defects in electrical work can cause electrical shock and/or fire.
DO NOT allow any substances or gases to enter the unit when connecting refrigerant piping. The presence of other gases or substances will lower the unit's capacity and may cause abnormally high pressure in the operation cycle. This could cause an explosion and/ or personal injury.
DO NOT connect the ground wire to a gas pipe, water pipe, lightning arrester, or telephone wire.
DO NOT allow children to play with the air conditioner. Children should be supervised around the unit at all times.
DO NOT alter the settings of the pressure sensor or other protective devices; if short-circuited or modified, fire and/or an explosion could occur.

1. Installation must be performed by an authorized technician. Improper installation may cause water leakage, electrical shock, and/or fire.
2. Installation must be performed according to installation instructions. Improper installation may cause water leakage, electrical shock, and/or fire.
3. In North America, installation must be performed in accordance with the requirements of the NEC and CEC (by authorized personnel only). Contact an authorized service technician for repair or maintenance of the unit.
4. Only use the included accessories and specified parts for installation. Using non-standard parts can cause water leakage, electrical shock, fire, and could cause the unit to fail.
5. The United States Environmental Protection Agency ("EPA") has issued various regulations regarding the introduction and disposal of refrigerants introduced into this unit. Failure to follow these regulations may harm the environment and can lead to a substantial fine. These regulations may vary due to the passage of laws. A certified technician must perform the installation and service of this product. Should questions arise, contact your local EPA office.

6. Install the unit in a firm location that can support the unit's weight. If the installation location cannot support the weight, or the installation is performed improperly, the unit could fall and cause serious injury and/or damage.
7. For all electrical work, follow all appropriate wiring standards, regulations, and the Installation Manual.
8. Connect electrical cables tightly and clamp them securely to prevent external forces from damaging the terminal. Improper electrical connections may overheat, causing fire and/or electrical shock.
9. All wiring must be properly arranged to ensure that the control board cover can close properly. If the control board cover is not closed properly, it can lead to corrosion and cause the connection points on the terminal to overheat, which could cause fire and/or electrical shock.
10. In certain functional environments, such as kitchens and server rooms, it is highly recommended to use specially designed air-conditioning units to accommodate those areas.
11. If the power or thermostat wires are damaged, they must be replaced by an authorized technician in order to avoid hazard.
12. This appliance should not be used by children (under the age of 8 years old) or persons with reduced physical, sensory or mental capabilities, or lack of experience and knowledge unless they have supervision or are given instruction concerning use of the appliance. They should be made to understand the hazards involved with the appliance. Children should not play with the appliance or perform cleaning and/or user maintenance.
13. Turn off the air conditioner and disconnect the power source before cleaning, otherwise electric shock could occur.
14. If installed in a compact space, ensure that there is adequate ventilation in case of leakage. Concentrations of refrigerant gas can lead to an explosion and other hazards.
15. The fixed wires connecting to this appliance must be configured with an all-pole disconnect under voltage class III.
16. Always wear safety glasses, protective clothing, work gloves, and have a fire extinguisher available during installation.
17. Always use a quenching cloth for brazing operations.

Note about Fluorinated Gases:

1. This air-conditioning unit contains R-410A fluorinated gases.
2. The refrigerant gas may not have an odor, so this should not be considered as a means of leak detection.
3. Installation, service, maintenance, and repair of this unit must be performed by a certified technician.
4. Product un-installation and recycling must be performed by a certified technician.
5. If the system has a leak-detection system installed, it should be checked for leaks at least once every 12 months.
6. Keep a record of all leak checks for the lifetime of the unit.

DO NOT install the unit within 3 feet (1 meter) of combustible materials if the unit is equipped with an auxiliary electric heater.
DO NOT install the unit in a location that may be exposed to combustible gases. If combustible gas accumulates around the unit, it could cause fire.
DO NOT operate your air conditioner in a room where it could be exposed to excessive amounts of water, such as a bathroom or laundry room. Too much exposure to water may cause electrical components to short circuit.
DO NOT put appendages or other objects into the air inlet or return grills.
DO NOT stop the appliance by directly cutting off the power. Ensure the unit is turned off first.
DO NOT install the appliance in areas with:

• oil, smoke, or volatile liquid; as plastic parts may deteriorate, adversely affecting the integrity and functionality of the appliance.
• corrosive gas; as this may corrode copper piping and welds, adversely affecting the integrity and functionality of the appliance.
  DO NOT force-dry the filter using an open flame or blowers, as this could damage it.

1. This appliance must be properly grounded during installation, or electrical shock may occur.
2. Install the drainage piping according to the instructions in this manual. Improper drainage could cause water damage to your home and property.
3. This appliance must be stored in a well ventilated area that is equal in size to the area specified for operation.
4. Use proper measures to protect the unit from rodents and other small animals that may damage electrical components, and cause the unit to malfunction.
5. If wired control (i.e. a wall-mount thermostat) is to be used, it should be connected before powering up the unit, otherwise it may not function properly.
6. Only use a soft dry cloth, or a slightly wet cloth with neutral detergent, to clean the casing of this appliance.
7. If the unit has been disconnected from its power source for an extended period of time, before operating the unit in low temperature, connect it to power for 8 hours. If it is to be deactivated for a short time, for example, one night, do not cut off the power (this is to protect the compressor).