Owner's Manual for MRCOOL models including: Universal Series, MDUO18048060, DC Inverter Heat Pump Condenser

Owner's Manual

MDUCO1848 Universal 4 Ton 48000 BTU up to 18 SEER DC Inverter AC Only Condenser 208/230-Volt Full Product Manual

MRCOOL MDUCO1848 810063868673 0810063868673 1006590312

MDUCO1860 Universal 5 Ton 54000 BTU up to 17 SEER DC Inverter AC Only Condenser 208/230-Volt Full Product Manual

MRCOOL MDUCO1860 810063868680 0810063868680 1006590313


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5465a89a-d8dd-4e27-adfe-a9c96010e75c
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. Version Date: 5-11-21
Thank you for choosing MRCOOL Please read this manual carefully before installation and keep it for future reference. Copyright © 2021 MRCOOL, LLC

Contents
! Safety Precautions ................................... 2
1 Appliance Overview ................................. 5
. Introduction ................................................................ 5 . Accessories ................................................................ 6 . Operating Range ........................................................ 7 . Unit Dimensions ........................................................ 7

2 Unit Installation ................................ 9

1. Installation Location ................................... 9

2. Outdoor Installation .................................. 14

MC

MC

3. Conventional Line Set Installation ......... 15

4. No-Vac® Quick Connect® Installation .... 24

5. Installation of Drain Pipe .......................... 25

6. Condenser Field Conversion ................... 26

7. Electrical Connection ................................ 27

3 Post Installation Checks ........... 32
4 Maintenance ...............................34
. Troubleshooting .................................. 34 . Error Codes .......................................... 36 . Unit Maintenance ............................... 37 . Notice on Maintenance ..................... 39 . After Sales Services ............................ 42
5 EU Disposal Guidelines ...... 43

Page 1

mrcool.com

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.

WARNING

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

CAUTION

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

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

WARNING
Please read the manual in its entirety before installing, operating or repairing.
DO NOT share the electrical circuit with other appliances. Improper or insufficient power supply can cause fire or electrical shock.
DO NOT let substances or gases, other than the refrigerant, 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 may cause explosion and 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 or even an explosion could occur.
1. Installation must be performed by an authorized technician. Improper installation may cause
water leakage, electrical shock, or fire.
2. Installation must be performed according to installation instructions. Improper installation may
cause water leakage, electrical shock, or fire.
3. In North America, installation must be performed in accordance with the requirement of 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, elctrical shock, or fire and may cause the unit to fail.
5. Before installing, modifying, or servicing the system, the main electrical disconnect switch must be
in the OFF position. There may be more than one disconnect switch. If there is another disconnect switch, in addition to the main switch, lock-out and tag this switch with a suitable warning label.

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Page 2

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, or the installation is performed improperly, the unit may fall and cause serious injury and/or damage.
7. For all electrical work, follow all appropriate wiring standards, regulations, and the Installation Manual.
8. You must use an independent circuit to supply power. Do not connect other appliances to the same circuit. Insufficient electrical capacity or defects in electrical work can cause electrical shock or fire.
9. Connect electrical cables tightly and firmly to the terminal board to prevent external forces from damaging the terminal.
10. 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, causing fire and/or electrical shock.
11. In certain functional environments, such as kitchens, server rooms, etc., the use of specially designed air-conditioning units is highly recommended. If the power or thermostat wires are damaged, it must be replaced by an authorized technician in order to avoid hazard.
12. This appliance can be used by children aged 8 years and above 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 made by children without supervision.
13. The air conditioner unit can only be cleaned after it has been turned off and disconnected from power, otherwise electric shock may 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/or other hazards.
15. The fixed wires connecting to this appliance must be configured with an all-pole disconnect under voltage class III.
16. Wear safety glasses, protective clothing, and work gloves during installation. Also, have a fire extinguisher available in case of an emergency.
17. Use a quenching cloth for brazing operations.
Note about Flourinated Gasses:
1. This air-conditioning unit contains R410A flourinated gases.
2. The refigerant gas may not have an odor, thus this should not be considered a means of leak detection.
3. Installation, service, maintenance, and repair of this unit must be performed by a certified technician.
4. Product uninstallation 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 every 12
months.
6. Keep a record of all leak checks for the lifetime of the unit.

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Safety Precautions
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 may cause fire. DO NOT operate your air conditioner in a wet room 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. 1. DO NOT stop the appliance by directly cutting off the power. Turn off the unit first.
.2. DO NOT install the appliance in areas with either of the following: 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 open flame or blowers, as this could damage it. DO NOT operate the air conditioner with wet hands. DO NOT wash or sprinkle water on the air conditioner, otherwise malfunction or electric shock will occur. 1. This appliance must be properly grounded during installation, or electrical shock may occur. 2. Install drainage piping according to the instructions in this manual. Improper drainage may cause
water damage to your home and property. 3. This appliance must be stored in a well ventilated area equal in size to the area specified for
operation. It must also be without a continously operating open flame (ex. an operating gas appliance) and ignition sources (ex. operating electric heater). 4. Use proper measures to protect the outdoor unit from rodents and other small animals that may damage electrical components, causing the unit to malfunction. 5. If wired control (ex: a wall-mount thermostat) is to be used, it should be connected first before powering up the unit, otherwise it may not function properly. 6. Only use a soft dry cloth or, as necessary, a slightly wet cloth with neutral detergent to clean the casing of this appliance. 7. Before operating the unit under low temperature, connect it to power for 8 hours. If it is deactivated for a short time (ex: for one night), do not cut off the power. This is done in order to protect the compressor. 8. If the unit is to be installed in a small space, please adopt protective measures to prevent the concentration of refrigerant from exceeding the allowable safety limit; excessive refrigerant leakage may lead to an explosion. 9. When installing or re-installing the air conditioner, please keep the refrigerant circuit away from substances other than the specified refrigerant, such as air. Any presence of foreign substances will cause an abnormal pressure change or even an explosion, resulting in injury. 10. Please adopt safety protection measures before touching the refrigerant pipe; otherwise injury may occur. 11. Please select the proper copper pipe according to the requirement for pipe thickness.

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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 UniveralTM Series Central HVAC System 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 above and persons with reduced physical, sensory, or mental capabilities or those who have a lack of experience and knowledge. However, they must be 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 made by children without supervision.
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. When 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:
a. Product Nameplate Contents (model number, cooling / heating capacity, product serial number, factory date)
b. 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 power or thermostat wire is damaged, it must be replaced by an authorized technician 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 instuction manual.
10. MRCOOL®, LLC will bear no responsibilities for personal injury or property damage caused by the following:
a. Improper use of the appliance
b. Altering, maintaining, or operating the product with non-approved equipment.
c. Altering, maintaining, or operating the product outside of the guidelines of this manual.
d. Defects caused by corrosive gas.
e. Defects caused by shipping damage.
f. Failure to abide by this instruction manual or government regulations.
g. Products made by other manufacturers
h. Natural disasters, improper installation environment, or force majeure.

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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, or equipment failure.

PART Owner's Manual
Drain Plug Drainage Connector

LOOKS LIKE...
Owner's Manual Universal®TM Series
Central Heating & Air Conditioning
or

QUANTITY
1
3 To plug the unused
drain hole 1
To connect with the PVC drain pipe

OPTIONAL

No-Vac®

Quick Connect®

1

Lineset

Gas / Liquid

Pipe Assembly

Liquid Side Stub Kit Gas Side Stub Kit

1 To connect the unit with the liquid pipe
1 To connect the unit
with the gas pipe

mrcool.com

Fig. 1.1 Page 6

Appliance Overview

Operating Range
Outdoor Temperature

COOLING
5°F (-15°C) ~ 129.2°F (54°C

HEATING
-22°F (-30°C) ~ 75.2°F (24°C

Unit Dimensions of 2-3 Ton Condenser MDUO18024036

Fig. 1.2

Outdoor Unit Dimensions
Width (A) x Height (C) x Depth (G)

MDUO18024036

37 in x 32-1/4 in x 18-1/8 in. (940 mm x 820 mm x 460 mm)

Mounting Dimensions

Width (A / D)

Depth (B / E)

37 in / 24 in (940 mm / 610 mm)

20-7/8 in / 19-1/8 in (530 mm / 486 mm)

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Appliance Overview

Operating Range
Outdoor Temperature

COOLING
5°F (-15°C) ~ 129.2°F (54°C

HEATING
-22°F (-30°C) ~ 75°F (24°C

Unit Dimensions of 4-5 Ton Condenser MDUO18048060

G E
C

A

B

D

Fig. 1.3

Outdoor Unit Dimensions
Width (A) x Height (C) x Depth (G)

Mounting Dimensions

Width (A / D)

Depth (B / E)

MDUO18048060 42-3/4 in x 53-3/4 in x 14-1/2 in 42-3/4 in / 24-1/2 in (1085 mm x 1365 mm x 370 mm) (1085 mm / 620 mm)

16-7/8 in / 15-1/2 in (427 mm / 395 mm)

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MRCOOL®
Preferred Method

Unit Installation

2

The UniversalTM Series has 2 installation methods
1. The Conventional Weld Line Set Installation 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
1 Installation Location
WARNING
1. The unit must be installed in a location strong enough to support the weight of the unit and fixed
securely, to avoid toppling.
2. Install the appliance in a location where there is an incline of less than 5°.
DO NOT install the unit in a location with direct sunlight to improve effciency. DO NOT install the unit where combustible or flammable gas leakage may occur.
Select an installation location for the outdoor unit pursuant to the following conditions: 1. Noise and air flow produced by the outdoor unit will not disturb neighbors. 2. The location is away from animals and plants. If not, please add safety fences to protect the unit. 3. The area is well-ventilated with no nearby obstacles that could obstruct air flow. 4. The location is able to support the weight and withstand the operating vibration of the unit. 5. Installation is able to be performed safely. 6. The location area is free of combustible or corrosive gas, and oil smoke. 7. Unit is able to be shielded from strong wind. Strong wind may affect the outdoor fan and lead to
insufficient air flow volume, thus affecting performance. 8. Unit is away from objects which can generate or amplify noise during operation. 9. Condensate can be safely drained from the unit.

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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

C
c d
D

e B Hb
Hb A
a
Hd

Fig. 2.1

A ~ E B
A,B,C, B,E
A,B,C,E D D,E B,D
B,D,E

Hb Hd H
-- -- -- -- -- -- Hb < Hd Hd > H 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
 11.81 in 300 mm  11.81 in 300 mm

inches (in) millimeters (mm)

b

c

d

 3.94 in 100 mm  3.94 in 100 mm  3.94 in 100 mm  5.9 in 150 mm
 3.94 in 100 mm  3.94 in 100 mm  9.84 in 250 mm  9.84 in 250 mm

 3.94 in 100 mm

 5.9 in 150 mm

 39.37 in 1000 mm  39.37 in 1000 mm  39.37 in 1000 mm  39.37 in 1000 mm  78.74 in 2000 mm
 78.74 in 2000 mm

Prohibited

 3.94 in 100 mm  7.87 in 200 mm

 78.74 in 2000 mm  78.74 in 2000 mm

Prohibited

e
 39.37 in 1000 mm  39.37 in 1000 mm  39.37 in 1000 mm
 39.37 in 1000 mm  39.37 in 1000 mm  39.37 in 1000 mm  39.37 in 1000 mm

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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

C
c
D

e  15.75 in 400 mm  15.75 in 400 mm
d
H
Hd

B Hb
b
A
a
Fig. 2.2

A ~ E

Hb Hd H

inches (in) millimeters (mm)

a

b

c

d

e

A,B,C, A,B,C,E
D D,E B,D
B,D,E

--

--

--

--

Hb < Hd Hd > H

Hb >Hd

Hd  1/2H Hd < H

Hb  1/2H

Hb < Hd 1/2H < Hb  H

Hb > H

Hd  1/2H

Hb > Hd 1/2H < Hd  H

Hd > H

 11.81 in 300 mm  11.81 in 300 mm

 11.81 in 300 mm  11.81 in 300 mm

 39.37 in 1000 mm  39.37 in 1000 mm

 11.81 in 300 mm  9.84 in 250 mm  11.81 in 300 mm  11.81 in 300 mm  11.81 in 300 mm

 78.74 in 2000 mm  78.74 in 2000 mm  78.74 in 2000 mm  78.74 in 2000 mm  98.43 in 2500 mm  78.74 in 2000 mm
 98.43 in 2500 mm

Prohibited

 9.84 in 250 mm  11.81 in 300 mm

 98.43 in 2500 mm  98.43 in 2500 mm

Prohibited

 39.37 in 1000 mm  39.37 in 1000 mm
 39.37 in 1000 mm  39.37 in 1000 mm  39.37 in 1000 mm  39.37 in 1000 mm

Page 11

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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:

 7.87 in 200 mm

 145070.50inmm
 7.87" 2070.8m7"imn 200 mmmm

 7.87"in 200 mmmm

 15.75 in 400 mm

 15.75 in 400 mm

Hb

H

 147570.107minm

B

 72.8070inmm

 23.62 in 600 mm

Fig. 2.3

Hb H
Hb  1/2H 1/2H < Hb  H
Hb > H

inches (in) millimeters (mm)
b  9.84 in (250 mm) b  11.81 in (300 mm)
Prohibited

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Page 12

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

WALL

 7.87 in 200 mm

 19.69 in 500 mm

 15.75"in 400 mmmm

Fig. 2.4

 19.69"in 500 mmmm
 11.81 in 300 mm

Page 13

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Unit Installation
2 Outdoor Installation
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. DO NOT install it on top of a building.
3. If the unit vibrates and generates noise, add rubber cushions between the unit's feet and the
installation surface.
4. When the outdoor unit is in heating or defrosting mode, it must drain water. When installing the
drain pipe, plug the accompanied drainage connector to the drainage hole on the chassis of the outdoor unit. Then, connect the drain hose to the drainage connector. If the drainage connector is used, the outdoor unit should be at least 4 in (101.6 mm) from the ground.
5. Plugs and drainage connector are not recommended if there is an electrical heater on the chassis.
Refer to Fig. 2.5 for details.

Fig. 2.5
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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 overtighten the screw 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. The pipe wall thickness should be 0.5-1.0 mm and able to withstand 6.0 MPa. Excessive length of the refrigerant lines will negatively affect cooling and heating performance. Attempt to minimize refrigerant line length when possible.
When the drop between indoor and outdoor units is larger than 32 ft (10 m), an oil return bend should be added every 19.69 ft (6 m).

LINE SET SIZE MUST MATCH SERVICE VALVE CONNECTION

Outdoor Unit Model
MDUO18024036 MDUO18048060

Size of Fitting Pipe

Liquid Pipe

Gas Pipe

3/8 in

3/4 in

DO NOT CRIMP SERVICE VALVE CONNECTOR IF PIPE IS
SMALLER THAN CONNECTOR

Maximum Pipe Length
98.4 ft (30 m)

Maximum Drop between indoor and
outdoor units
49.2 ft (15 m)

Be extremely careful not to dent or damage the piping while bending them away from the unit. Any dents in the piping will affect the unit's performance.

For installation with a No-Vac® Quick Connect® Line Set, refer to the next section starting on page 24

Page 15

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Unit Installation

OIL RETURN BENDS
Add an oil return bend as described below:
If outdoor unit is beneath the indoor unit, there is no need to add a non-return bend at the lowest or highest position of the vertical pipe, as shown below in Fig. 2.6:
If outdoor unit is above the indoor unit, it is necessary to add an oil return bend and a non-return bend at the lowest and highest position of the vertical pipe, as shown below in Fig. 2.7:

System gas pipe

Indoor unit

Non-return bend

Outdoor unit

System gas pipe

Oil return bend

Oil return bend

Fig. 2.6

Install an oil return bend every 19.7 ft (6 m)

Install an oil return bend every 19.7 ft (6 m)

Fig. 2.7

Outdoor unit

Indoor unit

Use the following dimensions in Fig. 2.8 to form the oil return bend(s):
B
A

C
Fig. 2.8

A (Pipe Diameter)

Inches 1/2

mm 12

5/8

16

3/4

19

B

Inches

mm

1

26

1.3

33

1.34

34

C
Inches 5.91 5.91 5.91

mm
150 150 150

For installation with a No-Vac® Quick Connect® Line Set, refer to the next section starting on page 24

mrcool.com

Page 16

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 efficient operation and minimize the need for future maintenance.

2. Measure the distance between the indoor and outdoor

units.

90°

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. 2.9 for cut examples.

CAUTION
DO NOT deform pipe while cutting. Be extra careful not to damage, dent, or deform the pipe while cutting. This will drastically reduce the heating efficiency of the unit.

Oblique Rough Warped Fig. 2.9
Pipe

Step 2: Remove burrs
Burrs can affect the airtight seal of refrigerant piping connection. They must be completely removed. 1. Hold the pipe at a downward angle to prevent burrs from Point downward falling into the pipe.
2. Using a reamer or deburring tool, remove all burrs from the cut section of the pipe. Refer to Fig. 2.10
3. After removing burrs from cut pipe, seal the ends with PVC tape to prevent foreign materials from entering the pipe.

Reamer Fig. 2.10

For installation with a No-Vac® Quick Connect® Line Set, refer to the next section starting on page 24

Page 17

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Unit Installation

Conventional Line Set Installation
Pipe Flaring

Step 3: Flare pipe ends Proper flaring is essential to achieve an airtight seal.

Flare nut

1. After removing burrs from cut pipe, seal the ends with PVC tape to prevent foreign materials from entering the pipe.

2. Sheath the pipe with insulating material as necessary

Copper pipe

3. 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.

4. Make sure it is facing in the right direction, because you can not remove the nut or change its direction after flaring. See Fig. 2.12.

5. Remove PVC tape from ends of pipe when ready to perform flaring work.

6. Clamp flare form on the end of the pipe. The end of the pipe should extend ~ 1/16 in (1.6 mm) beyond the edge of the flare form as shown in Fig. 2.13

7. Place flaring tool onto the form, as shown in Fig. 2.14

8. Turn the handle of the flaring tool clockwise until the pipe is fully flared.

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

PIPING EXTENSION BEYOND FLARE FORM Flare form

Fig. 2.11 Fig. 2.12
Fig. 2.13
A

A = ~1/16 in (1.6 mm)
Fig. 2.14

Pipe

For installation with a No-Vac® Quick Connect® Line Set, refer to the next section starting on page 24

mrcool.com

Page 18

Unit Installation

Conventional Line Set Installation

Pipe Bending

1. Use your hands to bend the pipes. Work carefully not to collapse them.

2. DO NOT bend the pipes in at an angle greater than 90°.

3. 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.

MINIMUM BEND RADIUS

4. DO NOT bend the pipe excessively, otherwise it will break. Please refer to Fig. 2.15

When bending connective refrigerant piping, the minimum bending radius is

10 cm. Refer to Fig. 2.15

Radius 4 in (10 cm)

Extend the pipe by unwinding it

Fig. 2.15
5. As shown in Fig. 2.16 , 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.

Pipe Pipe Insulation
Cutter
Cut line

Fig. 2.16

For installation with a No-Vac® Quick Connect® Line Set, refer to the next section starting on page 24

Page 19

mrcool.com

Unit Installation

Conventional Line Set Installation
Replacement Condenser Only
Fig. 2.17
MRCOOL Universal Series DC Inverter

Existing Air Handler

Existing Air Handler in house
must be 410 air handler and 410 TXV Biflow valve

Accessory copper 90 pipe Q+y*2

must have 410 TXV Biflow valve

Must install filter drier biflow with this installation type

Purge with Nitrogen
Weld joint

WELD Type Complete Unit Replacement

Fig. 2.18

DC Inverter

MRCOOL Universal Series

Must open stop valves after pulling vacuum and before powering on

Open stop valves with allen wrench only after finishing line set connections and before powering on the unit
Must install filter drier biflow with this installation type

Weld joint
Purge with Nitrogen
Must Purge with Nitrogen before brazing joints

Air Handler
Weld joint Must Purge with Nitrogen before brazing joints

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Page 20

Unit Installation
Conventional Line Set Installation
Pipe Connection
WARNING
1. Connect the pipe to the unit. Follow all instructions below. Use both spanner and torque wrench. 2. When connecting the tapered screw nut, first apply Polyolester oil (POE oil) on its inner and outer
surface and then screw it on 3 or 4 threads. 3. Confirm the tightening torque by referring to the following table. If the screw nut is overtightened, it
may be damaged and cause leakage. 4. Check whether gas leakage is occuring and then apply thermal insulation. 5. Wind sponge around the joint of gas pipe and heat insulation sheath of gas collecting pipe. 6. Be sure to connect gas pipe after liquid pipe is connected. 7. Keep pipe connection joint exposed to perform the leak test (refer to Post Installation Checks section
of this manual).
1. Screw on the flare nut of the flared connecting pipe onto the outdoor unit valve. Refer to Fig. 2.19A & Fig. 2.19B, using the torque values in the table below.

Cut Off Valve
Refrigerant Line Set Connection Pipes

Fig. 2.19A
Pipe diameter (in. | mm)
1/4 in | 6.4 mm 3/8 in | 8.3 mm 1/2 in | 12.7 mm 5/8 in | 15.9 mm 3/4 in | 19 mm 7/8 in | 22.2 mm

Knockout Holes

Fig. 2.19B

2. On Model MDUO18024036 & MDUO18048060 plug the knockout holes shown in Fig. 2.19A with material such as neoprene to prevent small animals and debris from entering the unit.

Tightening torque (N·m)
11-22 ft/lbs (15-30 Nm) 26-30 ft/lbs (35-40 Nm) 33-37 ft/lbs (45-50 Nm) 44-48 ft/lbs (60-65 Nm)

DO NOT USE EXCESSIVE TORQUE
Excessive force can break the nut or damage the refrigerant piping. You must not exceed torque requirements shown in the table.

52-55 ft/lbs (70-75 Nm)

59-63 ft/lbs (80-85 Nm)

For installation with a No-Vac® Quick Connect® Line Set, refer to the next section starting on page 24

Page 21

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Unit Installation
Conventional Line Set Installation
Vacuum Lines
WARNING
·Make sure the outlet of the vaccuum 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. Connect the hose at the low pressure and high pressure sides of the manifold valve assembly to the service port of the unit's gas and liquid valve. Meanwhile, the gas and liquid valves should be kept closed to avoid refrigerant leak.
3. Connect the hose used for evacuation hose to the vacuum pump.
4. Open the switch on the lower pressure side of the manifold valve assembly and start the vacuum pump. The switch at the high pressure side of the manifold valve assembly should be kept closed. If not, evacuation would fail.
5. The evacuation duration typically depends on the unit capacity: for Model MDUO18024036 time is generally 30 minutes, for model MDUO18048060 time is generally 45 minutes. Verify that the pressure gauge on the low pressure side of the manifold valve assembly reads -0.1 Mp (-30 in Hg). If it does not, there is leak somewhere. Close the switch fully and stop the vacuum pump.
6. Wait for 10 minutes to see if the system pressure remains unchanged. During this time, the reading of the pressure gauge at the low pressure side should not be larger than 0.005 Mp (0.15 in Hg).
7. Open the liquid valve slightly, and let some refrigerant go to the connection pipe to balance the pressure inside and outside of the connection pipe, so that air will not come into the connection pipe when removing the hose. Note that the gas and liquid valve can be opened fully only after the manifold valve assembly is removed.
8. Return the caps to the liquid valve, gas valve, and service port.
9. For large-sized units, there are maintenance ports for the liquid valve and gas valve. During evacuation, you may connect the two hoses of the branch valve assembly to the maintenance ports to speed up the evacuation.
Refer to Fig. 2.20 on the following page.

For installation with a No-Vac® Quick Connect® Line Set, refer to the next section starting on page 24

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Unit Installation
Conventional Line Set Installation
Vacuum Lines

Adding Refrigerant

Fig. 2.20

Outdoor Unit Model
MDUO18024036 MDUO18048060

Standard Pipe Length

Max Pipe Length

Additional Refrigerant

Requiring No Added Charge per Line Length

(Not for No-Vac Quick Connect)

24.6 ft | 7.5 m

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

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4 No-Vac® Quick Connect® Line Set Installation

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

Please read and follow the instrucons and diagram below : Connecons must be made exactly as specified to avoid system leaks and /or damage
1. Take out matching male connectors M1 and M2. 2. Remove protecve cap with the copper gasket at each stop valve on the DC INVERTER 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 (50N).
Tighten the M2 connector to the cutoff valve *2 with a ghtening force of 52 /lb (70N). 4. Repeat step 3 for AIR HANDLER at the other end of the LINE SET.
5. Unroll and route the LINE SET between the AIR HANDLER and the DC INVERTER.
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 (connected to cutoff valve *1 in step 3) with a force of 33 /lb (45N). Tighten
the LINE SET F2 valve to the M2 Connector (connected to cutoff valve *2 in step 3) with a ghtening force of 48 /lb (65N).
8. Repeat this process for the AIR HANDLER at the other end of the LINE SET.
9. At the OUTDOOR UNIT remove the protecve cap at the cutoff valve switch and open the cutoff valve with a hex wrench to run the refrigeraon circuit. If there is any fizz, grease, or other leakage, close the valve immediately and check that steps 3 and 7 were done properly. Otherwise, immediately apply soapy water for micro-leakage detecon. Soak the joints using a sponge or spray bole. If any bubbles form, close the valve immediately and check that steps 3 and 7 were done properly.
10. Aer the correct connecon, re-ghten the cutoff valve's protecon cap and cover the M1, M2 and F1, F2 connecons with the grey insulang sleeve to help prevent condensaon.

37 ft/lb *1
3/8" M1 F1

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

52 ft/lb *2
3/4" M2 F2

*1

M1 F1

37 ft/lb 3/8"

*2

M2 F2

52 ft/lb 3/4"

Air Handler

MRCOOL Universal Series

DC Inverter

Open the stop valve

only after connecting

the refrigerant lines

Connect using precharged line set with quick connect fittings in length 15, 25, 35, 50 feet

A-coil Precharged with 410 Refrigerant

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

www.mrcool.com

v01-28-2021

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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 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. The entire line set, including drain pipe should be supported and fixed onto the wall with saddles.
1 Sealed 2 Saddle 3 Drain Pipe
®

Fig. 2.21

MDUO18024036

MDUO18048060

If the outdoor unit is located on a level higher than the indoor unit, arrange the condensate drain according to Fig. 2.22.

1. Drain hose should be placed on the ground utilizing a trap.

2. The entire line set, including drain pipe should be wrapped with insulating tape to avoid water returning to the interior. Wrap the insulating tape from bottom to top.

3. The entire line set, including drain pipe should be supported and fixed onto the wall with saddles.

MDUO18024036

MDUO18048060

®

Page 25

Fig. 2.22
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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.

1. Make sure the unit is powered off. DO NOT attempt this conversion while the unit is powered on.

2. Locate the capacity dip switch on the condenser main board. The capacity dip switch is circled on the

photo below.

3. The default position of the capacity dip switch is 1 & 2 `Up' and 3 &4 `Down'. Up being a switch push

toward the letters (ON DIP). Down being a switch pushed toward the numbers (1 2 3 4).

4. The default position of the capacity dip switch is 36k.

5. To activate the 24k capacity, flip capacity dip switch 1 from the Up position to the Down position.

Fig. 2.24

Fig. 2.25

DEFAULT 3 TON

2 TON SETTING

Converting Unit From 5 Ton to 4 Ton

Follow these instructions during unit installation in order to enable a Universal® Series 5 ton condenser and air handler split system to operate at 4 ton capacity.

1. Make sure the unit is powered off. DO NOT attempt this conversion while the unit is powered on.

2. Locate the capacity dip switch on the condenser main board. The capacity dip switch is circled on

the photo below.

3. The default position of the capacity dip switch is 1 & 2 `Up' and 3 & 4 `Down'. Up being a swit

pushed toward the letters (ON DIP). Down being a switch pushed toward the numbers (1 2 3 4).

4. The default position of the capacity dip switch is 60k.

5. To activate the 48k capacity, flip capacity dip switch 1 from the Up position to the Down position.

Fig. 2.23

Fig. 2.26

Fig. 2.27

Location of Dip Switch on Condenser Main Board

DEFAULT 5 TON

4 TON SETTING

NOTE
Refer to the Universal Air Handler Installation Manual for Dip Swith Instructions and settings to convert the Universal Air Handler from 3 ton to 2 ton, or 5 ton to 4 ton.

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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 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 air conditioner. 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 cord and the thermostat wire must be effectively fixed. 5. The external power cord and the thermostat wire 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 cord and the thermostat wire must NOT be squeezed. Never pull, stretch or bend the wires. 7. The external power cord and the thermostat wire must NOT collide with any metal beam or edge on the ceiling, or touch any metal burrs or sharp metal edge. 8. Connect wires correspondingly by referring to the circuit diagram labeled on the unit or electric box. Screws must be tightened. NOTE: Slipped screws must be replaced by specialized flat-head screws. 9. 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 work must be done according to national wiring rules and regulations. 10. Wiring terminals should be connected firmly to the teminal board.

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UUnnititInInsstatalllalatitoionn

Electrical Connection

Electrical Parameters

Outdoor Unit Model MDUO18024036 MDUO18048060

Power Supply
208/230V 1Ph - 60Hz

Min. Circuit Ampacity
24 amps (3 Ton) 18 amps (2 Ton)
35 amps

Max. Fuse Size
35 amps (3 Ton) 20 amps (2 Ton)
45 amps

Connecting the Power Cord & Thermostat Wire

WARNING

1. Before work begins, please check to ensure the unit is powered OFF. 2. Improper wire connection may cause electrical components to burn. 3. Connect the wires firmly to the wiring box. Incomplete installation may create a fire hazard. 4. Ground wire must be connected.
For solid wires (Refer to Fig. 2.28 A): 1. Use wire cutters to cut off the wire end and then peel away about 25 mm of the insulation layer. 2. Use a screwdriver to unscrew the terminal screw on the terminal board. 3. Use nippers to bend the solid wire into a ring that fits the terminal screw. 4. Form a proper ring and then put it on the terminal board. Use a screwdriver to tighten up the terminal
screw. For braided wires (Refer to Fig. 2.28 B & Fig. 2.29): 1. Use wire cutters to cut off the wire end and then peel away about 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 fix the round terminal firmly on the peeled wire end. 4. Locate the round terminal conduit. Use a screwdriver to replace it and tighten up the terminal screw, as
shown in Fig. 2.29.

A. Solid Wire

B. Braided Wire
Solderless Terminal

1" (25mm) 3/8" (10mm)

Fig. 2.28 A Insulation Layer
Page 27

Fig. 2.28 B
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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

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Unit Installation

Electrical Connection
Connecting the Power Cord & Thermostat Wire
WARNING
1. High and low voltage wires should be led through different rubber rings of the electric box cover. 2. DO NOT bundle up the temperature thermostat wire, or lay them side by side, otherwise errors will occur. 3. High and low voltage wires should be secured separately. 4. Use screws to tighten the power cord and thermostat wire of the units on the terminal board. Improper connection may create a fire hazard. 5. If the power cord and thermostat wire are not correctly connected, the air conditioner may suffer damage. 6. Ground the units 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 cord, make sure the phase sequence of the power supply matches with the corresponding terminals, otherwise the compressor will get reversed and operate abnormally.

Electrical wiring of Single-phase unit: MDUO18024036 & MDUO18048060

Power

Breaker

208/230V L1

L1

1PH

L2

L2

60HZ

G

Indoor Unit

Y

B

D

Thermostat

R

C

G

LEGEND: Y- Compressor control signal B- is energized under the heating mode, means 4-way valve control D- defrosting signal R- 24V AC power supply C- 24V common
NOTE: When the outdoor unit defrosts, D will send an operation signal to the electric heater to avoid cold winds. However, the indoor fan should operate continuously, which is controlled by the wire controller. NOTE: As for the indoor units, which do not include D, there is no need to connect the D terminals. Fig. 2.31-A

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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.
Electrical wiring of Single-phase unit: MDUO18024036

Electrical wiring of Single-phase unit: MDUO18048060

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Refrigerant Piping Connection
Post Installation Checks

3

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 flare nut connections and confirm that the system is not leaking. · Confirm that gas and liquid (high and low pressure) valves are fully open.

List of Checks to Perform Is the main body installed securely?
Did you conduct a water leakage test?

Possible Malfunctions The unit may fall down, vibrate or
produce noise. Cooling capacity may become inadequate if there is a leak.

PASS/FAIL

Is the unit well insulated from heat?

Condensate, water droplets may occur.

Does water drain properly from drain hose?

Condensate, water droplets may occur.

Is the voltage consistent with the

The unit may fail or its components Outdoor (2): Indoor (2):

specifications stated on the nameplate?

may get burned.

Are the wires, piping, and valves installed correctly?

The unit may fail or its components may ignite.

Has the unit been safely grounded?

If not, there is a risk of electrical leakage.

Do the wire specifications comply with The unit may fail or its components

the requirements?

may ignite.

Are there any obstacles blocking the air Cooling capacity could be affected if

inlet or outlets of the units?

there is an obstruction.

Have you recorded the length of refrigerant pipe and the refrigerant
charge amount?

The refrigerant charging amount cannot be controlled.

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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: 1. DO NOT connect the power if the installation work is not completed. 2. Ensure control circuit is correct and all the wires are firmly connected. 3. Ensure cut-off valves of the gas pipe and liquid pipe are open. 4. The inside of the unit should be clean. Take irrelevant objects out if there are any. 5. After performing these checks, reinstall the front side plate.
Operation after connecting the power: 1. If all the above checks have been completed, power on the unit. 2. Make sure the unit runs normally. 3. If the outside temperature is more than 86°F (30°C), heating mode cannot be enabled. 4. If there are any loud and/or abnormal sounds contact MRCOOL® Tech Support immediately. NOTICE: 1. If you use the thermostat to turn off the unit and then immediately turn the unit on again, the compressor will need 3 minutes to restart. Even if you press "ON/OFF" button on the thermostat, it will not start up right away. 2. If there is no display on the temperature thermostat, it is probably because the connection wires between the unit and the temperature thermostat are not connected. Connect the connection wires, and recheck the display.

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Outdoor Unit Installation
MMaaiinntteennaannccee

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 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 fo 3 minutes. Wire connection is wrong.
Fuse or circuit breaker is broken.
Power failure. Wired connection or power plug is loose.
Air inlet and outlet of the units have been blocked. Improper temperature setting. Fan speed is too low. Airflow direction is incorrect. Doors or windows are open. Exposed to direct sunlight.
Too many heat sources in the room. Filter is blocked or dirty. Air inlet and outlet of the units have been blocked.

Corrective Measure Please wait for approx. 3 minutes.
Connect wires according to the wiring diagram. Replace the fuse or switch on the circuit breaker. Restart after power returns. Re-insert or adjust wires for proper connection to designated terminals. Clear the obstacles and keep the area well ventilated. Reset to a proper temperature. Reset to a proper fan speed. Change the direction of air louvers. Close them. Close curtains or louvers in front of the windows. Remove unnecessary heat sources. Replace with a new return filter. Clear the obstacles and keep the area well ventilated.

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Maintenance

The following situations are not operation failures.

Problem

Time of Occurrence

Cause

During operation.

Mist comes from the conditioner.

System switches to heating mode after defrosting.

If the unit is running under high humidity, the wet air in the room will be quickly cooled down.
Defrosting process will generate some water, which will turn to vapor.

The air conditioner is buzzing when operation begins.

Thermostat will be buzzing when it starts working. The noise will become weak 1 minute later.

When the unit is turned on, it purrs.

When the system has just started, the refrigerant is not stable. About 30 seconds later, the purr of the unit becomes low.

The air conditioner generates noise.

About 20 seconds after the unit first

It is the sound of the 4-way valve

enables heating mode or when defrosting switching direction. The sound will

under heating mode.

disappear after the valve is in position.

There is a hissing sound when the unit It's the sound of gaseous refrigerant that

has started or stopped and a slight

stops flowing and the sound of the

hissing sound during and after operation. drainage system.

There is a crunching sound during and after operation.

There is a hissing sound when the unit is turned on or suddenly stopped during operation or after defrosting.

Dust comes from the The unit starts operation after being

air conditioner.

unused for a long time.

The air conditioner During operation. generates smells.

Because of temperature change, the front panel and other components may swell and cause an abrasive sound. Because refrigerant suddenly stops flowing or changes the flow direction.
Dust inside the unit comes out together with the air.
Smells from the operating environment may be pulled through the air handler.

NOTICE
Check the above items and take appropriate corrective measures. If the air conditioner continues to improperly function, please turn off the air conditioner immediately and contact MRCOOL®, or your installing dealer.

Page 35

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Error Code

Maintenance

WARNING
1) When abnormalities occur, stop the unit immediately and disconnect the power. Contact MRCOOL®. If the unit continues to run abnormally, it may damage the unit and cause an electric shock or a fire hazard.
2) DO NOT attempt repairs to the appliance yourself. Improper repair and maintenance can create electric shock and fire hazards. Please contact MRCOOL® Tech Support for further guidance or a qualified professional for repairs.

If the display panel displays an error code, please refer to the following table:

Number Error Code

Error

1

E1

Compressor high pressure protection

2

E3

Compressor low pressure protection

3

E4

Compressor air discharge high-temperature protection

4

F2

Condenser temperature sensor error

5

F3

Outdoor ambient temperature sensor error

6

F4

Discharge temperature sensor error

7

F6

Outdoor unit tube temperature sensor error

8

EE

Outdoor unit memory chip error

9

H4

Overload

10

H5

IPM protection

11

H6

DC fan error

12

H7

Driver out-of-step protection

13

HC

Pfc protection

14

Lc

Startup failure

15

P0

Drive reset protection

16

P5

Over-current protection

17

P6

Master control and driver communication error

18

P7

Driver module sensor error

19

P8

Driver module high temperature protection

20

PA

AC current protection

21

Pc

Driver current error

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Maintenance

Number Error Code

22

PL

Bus low-voltage protection

23

PH

Bus high-voltage protection

24

PU

Charge loop error

25

ee

Driver memory chip error

26

e1

High pressure sensor error

27

C4

ODU jumper cap error

Error

Unit Maintenance
Warning 1) Only professionals may 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. 5) If you need to replace a component, contact a professional to repair the unit with a component supplied
by MRCOOL® to ensure the quality. 6) Improper operation may damage the unit, causing electric shock or fire. 7) Do not immerse the air conditioner in water or electric shock may occur. 8) Do not use water to rinse the unit during cleaning.
Warning 1) Before cleaning, ensure the power is off. Turn off at circuit breaker and remove the disconnect to
avoid electric shock. 2) Do not wash the air conditioner with water, otherwise fire or electric shock may occur. 3) When cleaning the filter, be careful. If you need to work from an elevated position, such as a ladder,
please exercise caution.

Page 37

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Maintenance
Unit Maintenance
Outdoor Heat Exchanger
Clean the heat exchanger on the outdoor unit at least once every two months. Remove the dust and sundries on the surface of the heat exchanger with a dust collector and nylon brush. If there is a compressed air source; 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.
Pre-Season Inspection Checklist 1) Check for blockages in the air inlet/outlet. 2) Check the ground connection and make sure it is still securely connected. 3) Check that the air filter screen is properly installed and clean. 4) If starting up the unit again after a long period of inactivity, present the power switch of the air
conditioner to "ON" status at least 8 hours prior to operation to preheat the crankcase of the compressor. 5) Check that the outdoor unit is firmly secured; 6) If problems are detected, contact your local service professional or MRCOOL®. Post-Season Maintenance Checklist 1) Deactivate the main power to the air conditioner. 2) Remove dust and debris from the outdoor unit. 3) If the outdoor unit starts to develop rust, paint the rusty location to prevent the corrosion from continuing to grow. Component Replacement Components are available from MRCOOL® and associated dealers.

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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 work being performed. Avoid work confined spaces. Section off the area around the workspace. Ensure conditions within the area are safe by removing potentially flammable material.
Ventilated Area
Ensure the area is adequately ventilated before opening the system or conducting any refrigerant work. Maintain adequate ventilation while working. Effective ventilation will safely disperse any released refrigerant into the atmosphere.
Refrigeration Equipment Checks
Ensure all electrical components are compatible with the product and built to the correct specifications. Follow manufacturer maintenance and service guidelines at all times. When in doubt, consult the MRCOOL® technical department for assistance.
If using flammable refrigerants, conduct the following checks:
1) Ensure ventilation machinery and outlets are operating adequately and are not obstructed. 2) If an indirect refrigerating circuit is being used, check the secondary circuit for the presence of
refrigerant. 3) Check that equipment markings are visible and legible. If they are not, replace with markings that
are legible. 4) Ensure refrigeration 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 being corroded, or are suitably protected against being corroded. Electrical Device Checks
Electrical component repair and maintenance should include initial safety checks and component inspection procedures. If a fault exists that could compromise safety, DO NOT connect the circuit to an electrical supply until the fault is corrected.

Page 39

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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 safely grounded.
Sealed Component Repairs
ELECTRICAL SAFETY
Ensure that this system is installed using a disconnect box that meets national, state, and local electrical and HVAC code requirements. The location of the disconnect box(es), number of disconnect box(es) needed, and distance from the unit(s) to the disconnect box(es) should be handled in accordance with national, state, and local electrical and HVAC code. Also ensure that there is a permanent form of leak detection, at the most critical point, to warn of a potentially hazardous situation.
ATTENTION
1) Electrical component casings should not be altered in such a way that the level of protection is affected. This includes, damage to cables, excessive number of connections, terminals not made to original specification, damage to seals, incorrect fitting of glands, etc.
2) Ensure the apparatus is securely mounted. 3) Ensure the seals or sealing materials have not degraded in such a way that they no longer
serve the purpose of preventing the ingress of flammable atmospheres. 4) Replacement parts should be in accordance with manufacturer specifications.
NOTICE
The use of silicon sealant may inhibit the effectiveness of some types of leak detection equipment. Intrinsically safe components do not have to be isolated prior to working on them.
Intrinsically Safe Component Repair
1) DO NOT apply any permanent inductive or capacitance loads to the circuit without first ensuring that this will not exceed the permissable voltage and current permitted for the equipment in use.
2) Intrinsically safe components are the only types that can be worked on while live in the presence of a flammable atmosphere. The test apparatus must be at the correct rating.
3) Replace components only with parts specified by the manufacturer. Other parts may result in the ignition of refrigerant in the atmosphere from a leak.

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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) Ensure refrigerant contamination does not occur when charging equipment. 2) Hoses or lines should be as short as possible to minimize the refrigerant contained in them. 3) Cylinders must be kept upright. 4) Ensure that the system securely and properly grounded prior to charging the system with
refrigerant. 5) Take extreme care to avoid overfilling the refrigerant. 6) Label the system when charging is complete (if not already). 7) Prior to recharging the system, pressure test with OFN. The system must be leak tested whe
charging is complete and prior to commissioning. A follow up leak test must be carried out before leaving the site.

Decommissioning
Before decommissioning, it is essential that the technician become completely familiar with all of the equipment in detail. It is recommended, and good practice, that all refrigerants be recovered safely. Before decommissioning, an oil and refrigerant sample should be taken. This is done in case an analysis is required prior to the re-use of the reclaimed refrigerant. It is essential that electrical power is available before the task is commenced.
Before decommissioning procedure, ensure the following: 1) You are familiar with the equipment and its operation. 2) The system has been isolated electrically. 3) Mechanical handling equipment is available, if required, for handling refrigerant cylinders. 4) All personal protective equipment is available and being used correctly. 5) The recovery process is supervised at all times by a qualified person. 6) Recovery equipment and cylinders conform to the appropriate standards.
Decommissioning procedure: 1) Pump down refrigerant system, if possible. 2) If a vacuum is not possible, make a manifold so that refrigerant can be removed from various parts
of the system. 3) Make sure that cylinder is situated on the scales before recovery takes place. 4) Start the recovery machine and operate in accordance with manufacturer's instructions. 5) DO NOT overfill cylinders. Cylinders should have no more than an 80% volume of liquid charge.

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Maintenance

Notice on Maintenance
Decommissioning (cont.)
6) DO NOT exceed the maximum working pressure of the cylinder, not even temporarily. 7) When the cylinders have been filled correctly and the process completed, ensure the cylinders and the
equipment are removed from site promptly and all isolation valves on the equipment are closed. 8) Recovered refrigerant must not be charged into another refrigeration system until it has been cleaned and
checked.
Labelling
Equipment should be labelled to state that it has been decommissioned and emptied of refrigerant. The label must be dated and signed.
Recovery
When removing refrigerant from a system, either for servicing or decommissioning, it is a recommended, and good 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 are available. Ensure that all cylinders to be used are designated for the recovered refrigerant and labelled for that refrigerant. Cylinders should be complete with pressure relief valve and associated shut-off valves in good working order.
In addition to the cylinders, a set of calibrated weighing scales shall be available and in good working order. Hoses shall be complete with leak-free disconnect couplings and in good condition. Before using the recovery machine, check that it is in satisfactory working order and has been properly maintained. Consult the manufacturer if in doubt.
The recovered refrigerant should be returned to the refrigerant supplier in the correct recovery cylinder, and the relevant Waste Transfer Notice arranged. Do not mix refrigerants in recovery units and especially not in cylinders.
If compressors or compressor oils are to be removed, ensure that they have been evacuated to an acceptable level to make certain that flammable refrigerant does not remain within the lubricant. The evacuation process shall be carried out prior to returning the compressor to the suppliers. Only electric heating to the compressor body shall be employed to accelerate this process. When oil is drained from a system, it shall be carried out safely.
After-Sales Services
Any quality issues or other problems encountered with the purchased air conditioner, please contact the local MRCOOL® after-sales service department.

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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. · When buying a new appliance, the retailer will receive the old appliance free of charge. · The manufacturer will receive the old appliance free of charge. · Sell the appliance to certified scrap metal dealers.
Special notice Disposing of this appliance in the forest or other natural surroundings endangers your health and is bad for the environment. Hazardous substances may leak into the ground water and enter the food chain.

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UniversalTM 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.


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