Please read this manual carefully before installation and keep it for future reference. Owner’s Manual Universal® Series DC Inverter / Condenser MDUO18* Due to updates and constantly improving performance, the information and instructions within this manual are subject to change without notice. Please visit www.mrcool.com/documentation to ensure you have the latest version of this manual.
Contents ! Safety Precautions ................................... 2 1 Appliance Overview ................................. 5 . Introduction ................................................................ 5 . Accessories ................................................................ 6 . Operating Range ........................................................ 7 . Unit Dimensions ........................................................ 7 2 Unit Installation ................................ 9 1.
Safety Precautions 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 ignoring instructions may cause death or serious injury. WARNING This symbol indicates that ignoring instructions may cause moderate personal injury, damage to your unit, or other property.
Safety Precautions 6. Install the unit in a firm location that can support the unit’s weight. If the installation location cannot support the weight of the unit, 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 this installation manual. 8. You must use an independent circuit to supply power. DO NOT connect other appliances to the same circuit.
Safety Precautions DO NOT install the unit within 3 ft (1 m) 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 and/or an explosion. 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.
Safety Precautions Appliance Overview 1 To Our Customers; Thank you for choosing a MRCOOL® home HVAC product. Please read this manual carefully before installation and operation of the Universal™ Series Condenser 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.
Appliance Overview Unless otherwise stated (as “OPTIONAL”) the air conditioning system includes the following accessories. 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. PART LOOKS LIKE...
Appliance Overview Operating Range Outdoor Temperature COOLING HEATING 5°F (-15°C) ~ 129.2°F (54°C) -22°F (-30°C) ~ 75.2°F (24°C) Unit Dimensions of 2-3 Ton Condenser MDUO18024036 Fig. 1.2 Model MDUO18024036 Page 7 Outdoor Unit Dimensions Mounting Dimensions Width (A) x Height (C) x Depth (G) 37 in x 32-1/4 in x 18-1/8 in. (940 mm x 820 mm x 460 mm) Width (A / D) Depth (B / E) 37 in / 24 in 20-7/8 in / 19-1/8 in (940 mm / 610 mm) (530 mm / 486 mm) mrcool.
Appliance Overview Operating Range Outdoor Temperature COOLING HEATING 5°F (-15°C) ~ 129.2°F (54°C) -22°F (-30°C) ~ 75°F (24°C) Unit Dimensions of 4-5 Ton Condenser C MDUO18048060 B Model E G D A Outdoor Unit Dimensions Width (A) x Height (C) x Depth (G) Fig. 1.3 Mounting Dimensions Width (A / D) Depth (B / E) MDUO18048060 39-3/8 in x 53-3/4 in x 14-1/2 in 39-3/8 in / 24-1/2 in 16-7/8 in / 15-1/2 in (1000 mm x 1365 mm x 370 mm) (1000 mm / 620 mm) (427 mm / 395 mm) mrcool.
2 Unit Installation The Universal® Series has 2 installation methods 1. The Conventional Weld Line Set Installation MRCOOL® Preferred Method Instructions can be found on pages 15 - 23 OR View complete install video by scanning this QR code 2. No-Vac® Quick Connect® Line Set* Installation Instructions can be found on page 24 OR View complete install video by scanning this QR code *Pat. https://mrcool.com/mrcool-patents/ 1 Installation Location WARNING 1.
Unit Installation Installation Location For best performance of the outdoor unit, make sure its installation space conforms to the following installation dimensions: For installation of a single condenser refer to Fig 2.1 below: E e B Hb C H c b A a d D Hd A~E B A,B,C, B,E A,B,C,E D D,E B,D B,D,E Hb Hb < Hd Hb >Hd Hd — — — — — — H Hd > H Hd < H Hb ≤ 1/2H Hb < Hd 1/2H < Hb ≤ H Hb > H Hd ≤ 1/2H Hb > Hd 1/2H < Hd ≤ H Hd > H a ≥ 11.81 in 300 mm ≥ 11.81 in 300 mm Fig. 2.
Unit Installation Installation Location For best performance of the outdoor unit, make sure its installation space conforms to the following installation dimensions: For installation of multiple condensers side by side refer to Fig 2.2 below: E e ≥ 15.75 in 400 mm ≥ 15.75 in 400 mm C B Hb c b D Hd A~E Hb B,D B,D,E Page 11 Hd H — — — — A,B,C, A,B,C,E D D,E Hb < Hd A d Hd > H Hd ≤ 1/2H Hb >Hd Hd < H Hb ≤ 1/2H Hb < Hd 1/2H < Hb ≤ H Hb > H Hd ≤ 1/2H Hb > Hd 1/2H < Hd ≤ H Hd > H a ≥ 11.
Unit Installation Installation Location For best performance of the outdoor unit, make sure its installation space conforms to the following installation dimensions: For installation of multiple condensers in rows refer to Fig 2.3 below: in 7.5 mm 5 ≥ 1 00 40 ≥ 7.87 7.87”in 200 mm 200mm ≥ 7.87” ≥ 7.87 in 200 mm ≥200mm 7.87”in 7.87 200 mm 200mm ≥ 15.75 in 400 mm ≥ 15.75 in 400 mm Hb in .17 m 7 7 ≥ 1 00 m 45 H ≥ 23.62 in 600 mm in .87 m 7 ≥ 0m 20 Hb H Hb ≤ 1/2H 1/2H < Hb ≤ H Hb > H B Fig. 2.
Unit Installation Installation Location For best performance of the outdoor unit, make sure its installation space conforms to the following installation dimensions: For installation of multiple condensers on a vertical face refer to Fig 2.4 below: ≥ 15.75 in 400 mm ≥ 19.69 in 500 mm WALL ≥ 7.87 in 200 mm Fig. 2.4 15.75”in ≥ 15.75 400mm 400 mm ≥ 19.69 19.69”in 500mm 500 mm ≥ 11.81 in 300 mm Page 13 mrcool.
Unit Installation 2 Outdoor Installation DO NOT install outdoor unit on top of a building. 1. If the outdoor unit is installed on a solid surface, such as concrete, use M10 screw bolts and nuts to secure the unit. Make sure the unit stands erect and level. 2. If the unit vibrates and generates noise, add rubber cushions between the unit’s feet and the installation surface. 3. When the outdoor unit is in heating or defrosting mode, it must drain water.
Unit Installation 3 Conventional Line Set Installation INSTALLATION METHOD Connect the refrigerant lines to the unit first. When bending a refrigerant pipe, be careful not to kink or crimp the pipe. DO NOT over-tighten the flare nut, otherwise leakage may occur. The outside of the refrigerant pipe should have a layer of insulating cotton to protect it from mechanical damage during installation, maintenance, and transportation. Refrigerant lines should adopt water-proof insulating material.
Unit Installation OIL RETURN BENDS Add an oil return bend as described below: • If the outdoor unit is installed beneath the indoor unit, install an oil return bend every 20 ft (6 m). A non-return bend is not needed in this configuration. Please refer to Fig. 2.6 below: • If the outdoor unit is installed above the indoor unit, install an oil return bend every 20 ft (6 m). It is also necessary to add a non-return bend at the lowest and highest position of the vertical pipe, as shown below in Fig. 2.
Unit Installation Conventional Line Set Installation Pipe Cutting Step 1: Cut Pipe 1. When preparing refrigerant pipes, take extra care to cut and flare them properly. This will ensure an airtight seal, efficient operation, and, minimize the need for future maintenance. 2. Measure the distance between the indoor and outdoor units. 90° Oblique Rough Warped 3. Using a pipe cutter, cut the pipe a little longer than the measured distance. 4. Make sure that the pipe is cut at a perfect 90° angle. Refer to Fig.
Unit Installation Conventional Line Set Installation Pipe Flaring Step 3: Flare pipe ends Flare nut Proper flaring is essential to achieve an airtight seal. 1. Sheath the pipe with insulating material as necessary 2. Remove the cut-off valve of outdoor unit and take out the flare nut from the bag of indoor unit accessories. Fit the flare nut on the pipe, as shown in Fig 2.11. Copper pipe 3. Make sure it is facing in the right direction, because you cannot remove the nut or change its direction after flaring.
Unit Installation Conventional Line Set Installation Pipe Bending 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°. MINIMUM BEND RADIUS DO NOT bend the pipe excessively, otherwise it will break.
Unit Installation Conventional Line Set Installation Replacement Condenser Only Existing Air Handler Fig. 2.
Unit Installation Conventional Line Set Installation Pipe Connection WARNING 1. Connect the pipe to the unit. Follow all instructions below. Use both a spanner and torque a wrench. 2. When connecting the tapered flare nut, first apply Polyolester oil (POE oil) on its inner and outer surface and then screw the flare nut by hand 3 or 4 threads to ensure it does become crooked. 3. Be sure to connect gas pipe after the liquid pipe is connected. 4. Confirm the tightening torque by referring to the table below.
Unit Installation Conventional Line Set Installation Vacuum Lines WARNING • Make sure the outlet of the vacuum pump is away from any potential source of fire and is well ventilated. • Before vacuum pumping, make sure the unit cut-off valves are closed. • When vacuum pumping, both the liquid pipe and the gas pipe must be pumped. 1. Remove the caps on the liquid valve, gas valve, and also the service port. 2.
Unit Installation Conventional Line Set Installation Vacuum Lines Fig. 2.20 Adding Refrigerant Outdoor Unit Model MDUO18024036 MDUO18048060 Standard Pipe Length 24.6 ft | 7.5 m Max Pipe Length Additional Refrigerant per Line Length Requiring No Added Charge (Not for No-Vac Quick Connect) ≤31.2 ft | ≤9.5 m 0.32 oz/ft 30 g/m For installation with a No-Vac® Quick Connect® Line Set, refer to the next section starting on page 24 Page 23 mrcool.
No-Vac® Quick Connect® Line Set* Installation INSTRUCTIONS FOR USE WITH NO-VAC™ QUICK CONNECT® LINE SET* SOLD SEPARATELY KINK RESISTANT, PRECHARGED, SIMPLE SECURE QUICK CONNECT, 100% CONNECTION GUARANTEE Please read and follow the instruc�ons and diagram below* : Connec�ons must be made exactly as specified to avoid system leaks and /or damage 1. Take out matching male connectors M1 and M2. 2.
Unit Installation 5 Installation of Drain Pipe If the outdoor unit is located on a level lower than the indoor unit, arrange the condensate drain according to Fig. 2.21. 1. Drain hose should be placed on the ground and its end should not be immersed into water. 2. The entire line set, including the drain pipe, should be wound with insulating tape. Wrap the insulating tape from bottom to top, as this will ensure rain/moisture does not seep into the tape overlaps. 3.
Unit Installation 6 Condenser Field Conversion Converting Unit From 3-Ton to 2-Ton Follow these instructions during unit installation in order to enable a Universal® Series 3-ton condenser and air handler split system to operate at 2-ton capacity. DO NOT attempt this conversion while the unit is powered on. 1. Locate the capacity dip switch on the condenser main board. The capacity dip switch is circled on the photo below. 2. The default position of the capacity dip switch is 1 & 2 ‘Up’ and 3 & 4 ‘Down’.
Unit Installation 7 Electrical Connection Electrical Regulations WARNING Before performing electrical work, read the following regulations 1. Electrical installation must be conducted only by professionals in compliance with local laws, regulations, and this installation manual. Never artificially extend the length of power cord. The electric circuit must be equipped with a circuit breaker and air switch. Both of these must have sufficient capacity. 2.
Unit UnitInstallation Installation Electrical Connection Electrical Parameters Outdoor Unit Model Power Supply Min. Circuit Ampacity Max. Fuse Size MDUO18024036 208/230V 1Ph - 60Hz 24 amps 35 amps 35 amps 45 amps MDUO18048060 Connecting the Power Cord & Thermostat Wire WARNING 1. Before work begins, please check to ensure the unit is powered OFF. 2. Improper wire connections could cause electrical components to burn. 3. Connect the wires securely to the wiring box.
Unit Installation Electrical Connection Connecting the Power Cord & Thermostat Wire Screw with special washer Round Terminal Terminal Board Fig. 2.29 Wire For all terminal wiring (Refer to Fig. 2.30): 5. Lead the thermostat wire and power cord through the insulation tube, as shown in Fig. 2.30. Fig. 2.30 Page 29 mrcool.
Unit Installation Electrical Connection Connecting the Power Cord & Thermostat Wire WARNING DO NOT bundle up the temperature thermostat wires and power wires, or lay them side by side, otherwise errors will occur. 1. High and low voltage wires should be led through different rubber rings of the electric box cover. 2. High and low voltage wires should be secured separately. 3. Use screws to tighten the power cord and thermostat wire of the units on the terminal board.
Unit Installation Electrical Connection Connecting the Power Cord & Thermostat Wire 1. Remove the big handle/front panel of the outdoor unit and insert one end of the thermostat wire and the power cord to the terminal board. 2. The power cord should be secured along with the right side plate and fixed to the hook with a wire clamp so as to avoid contacting the pipeline. The temperature thermostat wire should also be laid along with the right side plate but away from the power cord.
3 Refrigerant Piping Connection 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 the system is not leaking. • Confirm that gas and liquid (high and low pressure) valves are fully open.
Post Installation Checks Test Run DOUBLE-CHECK PIPE CONNECTIONS During operation, the pressure of the refrigerant circuit will increase. This may reveal leaks that were not present during your initial leak check. Take time during the Test Run to double-check that all refrigerant pipe connection points do not have leaks. Test Run Instructions Preparation before connecting the power: DO NOT connect the power if the installation work is not completed. 1.
Maintenance Maintenance Outdoor Unit Installation 44 Troubleshooting If your air conditioner fails to function normally, check the following items before conducting maintenance: Problem The air conditioner will not activate. Inadequate cooling Cause Corrective Measure If you turn off the unit and then immediately turn it on, in order to protect the compressor and avoid system overload, compressor will delay running for 3 minutes. Please wait for approx. 3 minutes. Wire connections are incorrect.
Maintenance The following situations are not operation failures. Problem Mist comes from the conditioner. The air conditioner generates noise. Time of Occurrence Cause During operation. If the unit is running under high humidity, the wet air in the room will be quickly cooled down. System switches to heating mode after defrosting. Defrosting process will generate some water, which will turn to vapor. The air conditioner is buzzing when operation begins. When the unit is turned on, it purrs.
Maintenance Error Code WARNING • When abnormalities occur, stop the unit immediately and disconnect the power. Then, contact MRCOOL® Tech Support at the number below. If the unit continues to run abnormally, it could damage the unit and cause electric shock, personal injury, and/or create a fire hazard. DO NOT attempt repairs to the appliance yourself. Improper repair and maintenance can cause electric shock, personal injury and/or create a fire hazard.
Maintenance Number Error Code Error 22 PL Bus low-voltage protection 23 PH Bus high-voltage protection 24 25 26 27 PU ee e1 C4 Charge loop error Driver memory chip error High pressure sensor error ODU jumper cap error Unit Maintenance Warning 1) Only trained professionals should carry out annual maintenance. 2) Before contacting any wire, make sure power is turned off. 3) Do not allow flammable objects near the unit. 4) Do not use organic solvent to clean the air conditioner.
Maintenance Unit Maintenance Outdoor Heat Exchanger Clean the heat exchanger on the outdoor unit at least once every two months. Remove the dust and debris on the surface of the heat exchanger with a dust collector and nylon brush. If a compressed air source is available; use the compressed air to gently blow the dust off the surface of the heat exchanger. DO NOT use tap water for cleaning. Condensate Drain Periodically check if the condensate drain is blocked to avoid condensate water problems.
Maintenance Notice on Maintenance Service Information The manual contains specific information for service personnel who will perform maintenance on the product. General Work Area Inform others working in the immediate vicinity about the nature of the work being performed. Avoid working in confined spaces. Section off the area around the workspace. Ensure conditions within the area are safe by removing potentially flammable material.
Maintenance Electrical Device Checks Initial safety checks should include: 1. The safe discharge of capacitors to avoid the possibility of sparking. 2. Ensure that no live electrical components and wiring are exposed while charging, recovering, or purging the system. 3. Ensure that the system is securely and safely grounded. Sealed Component Repairs ELECTRICAL SAFETY Ensure that this system is installed using a disconnect box that meets national, state, and local electrical & HVAC code requirements.
Maintenance Notice on Maintenance Cabling Check that the cabling will not be subject to wear, corrosion, excessive pressure, vibration, sharp edges, or any other adverse environmental effects. The check should also take into account the effects of aging or continual vibration from sources such as compressors or fans. Charging Procedures In addition to conventional charging procedures, the following parameters must be followed: 1. 2. 3. 4.
Maintenance Notice on Maintenance Decommissioning (cont.) DO NOT exceed the maximum working pressure of the cylinder, not even temporarily. 7. When the cylinders have been filled correctly and the process is completed, ensure the cylinders and the equipment are removed from site promptly and that all isolation valves on the equipment are closed. 8. Recovered/Reclaimed refrigerant must not be charged into another refrigeration system until it has been cleaned and checked.
Refrigerant Piping Connection EU Disposal Guidelines 6 This appliance contains refrigerant and other potentially hazardous materials. When disposing of this appliance, the law requires special collection and treatment. DO NOT dispose of this product as household waste or unsorted municipal waste. When disposing of this appliance, you have the following options: • Dispose of the appliance at a designated municipal electronic waste collection facility.
Universal Series ® ELECTRICIAN and/or HVAC TECHNICIAN: LICENSE #: INSTALLATION DATE: INSTALLATION LOCATION: SERIAL NUMBER: The design and specifications of this product and/or manual are subject to change without prior notice. Consult with the sales agency or manufacturer for details. Copyright © 2021 MRCOOL, LLC.
