McQuay MMC100D User Manual (English)

Questions and Answers:

G
Gary RussoAug 8, 2025
Why is my McQuay Air Conditioner working but not cooling properly?
- D
  Deborah Smith MDAug 8, 2025
  If your McQuay Air Conditioner isn't cooling well, it might be due to several reasons. First, ensure the thermostat isn't set too high by resetting it. Check that all doors and windows are properly closed. Also, make sure there are no obstructions blocking the unit's inlet or outlet; if there are, remove them. For issues such as a dirty condenser coil or insufficient refrigerant charge, it's best to contact your local dealer for assistance.
T
thomas92Aug 19, 2025
What to do if both fan and compressor of McQuay MMC100D do not work?
- K
  Kevin MorrisAug 19, 2025
  If both the fan and compressor on your McQuay Air Conditioner aren't working, there could be a few reasons. First, check for a power failure and wait for the power supply to resume. If there was a starter trip, try resetting the starter. Also, inspect the power switch or operating unit for a blown fuse, and replace it if necessary.
S
Shannon StantonAug 29, 2025
Why is the compressor not working on my McQuay MMC100D Air Conditioner, but the fan is?
- G
  Gary GuzmanAug 29, 2025
  If the fan in your McQuay Air Conditioner is running but the compressor isn't, it could be due to a few things. First, make sure the thermostat isn't set too high; if it is, reset it. Another possibility is a dual pressure control trip, in which case you should reset the pressure control. If the compressor itself or the compressor contactor is faulty, it's best to contact your local dealer.

McQuay MMC100D Specifications

General

Brand	McQuay
Model	MMC100D
Category	Air Conditioner
Language	English

Summary

General Specifications

Safety Controls

Outdoor units have auto reset high/low pressure cut-outs and discharge thermostat.

Specifications

Cooling only 50Hz (R22)

Detailed specifications for cooling-only units operating at 50Hz with R22 refrigerant.

Heatpump 50Hz (R22)

Detailed specifications for heatpump units operating at 50Hz with R22 refrigerant.

Cooling only 50Hz (R407C)

Detailed specifications for cooling-only units operating at 50Hz with R407C refrigerant.

Cooling only 220V – 60Hz (R22)

Detailed specifications for cooling-only units at 220V/60Hz with R22 refrigerant.

Cooling only 460V – 60Hz (R22)

Detailed specifications for cooling-only units at 460V/60Hz with R22 refrigerant.

Performance Tables

R22 50Hz COOLING CAPACITY

Cooling capacity performance tables for R22, 50Hz units.

Operating Range

Cooling only

Allowable operating temperature ranges for cooling-only operation.

Heat pump

Allowable operating temperature ranges for heatpump operation (Heating and Cooling).

Wiring Diagrams (Cooling)

MODEL : MDB 075D vs MMC 075D (WITH U1.4 MAINBOARD AND SLM3 HANDSET)

Wiring diagram for MDB 075D/MMC 075D units with specific controller.

MODEL : MDB 100D vs MMC 100D (WITH U1.4 MAINBOARD AND SLM3 HANDSET)

Wiring diagram for MDB 100D/MMC 100D units with specific controller.

MODEL : MDB 125D vs. MMC 125D ( WITH U1-125 MAINBOARD AND SLM3 HANDSET )

Wiring diagram for MDB 125D/MMC 125D units with specific controller.

MODEL : MDB 150D vs. MMC 150D (WITH U1-125 MAINBOARD AND SLM3 HANDSET)

Wiring diagram for MDB 150D/MMC 150D units with specific controller.

MODEL : MDB 150D2 vs. MMC 075D x 2

Wiring diagram for MDB 150D2/MMC 075D x 2 units with sequential controller.

MDB 200D2 vs. MMC 100D x 2

Wiring diagram for MDB 200D2/MMC 100D x 2 units with sequential controller.

MDB 250D2 vs. MMC 125D x 2

Wiring diagram for MDB 250D2/MMC 125D x 2 units with sequential controller.

MODEL : MDB 300D2 vs. MMC 150D x 2 (WITH SEQUENTIAL CONTROLLER)

Wiring diagram for MDB 300D2/MMC 150D x 2 units with sequential controller.

MODEL : MDB 400D4 vs. MMC 100D x 4

Wiring diagram for MDB 400D4/MMC 100D x 4 units with sequential controller.

MDB 500D4 vs. MMC 125D x 4 WITH SEQUENTIAL CONTROLLER

Wiring diagram for MDB 500D4/MMC 125D x 4 units with sequential controller.

Wiring Diagrams (Heatpump)

MODEL : MDB 075DR vs. MMC 075DR (WITH U1.4 / SLM3 HANDSET)

Heatpump wiring diagram for MDB 075DR/MMC 075DR units with specific controller.

MODEL : MDB 100DR vs. MMC 100DR (WITH U1.4 / SLM3 HANDSET)

Heatpump wiring diagram for MDB 100DR/MMC 100DR units with specific controller.

MODEL : MDB 125DR vs. MMC 125DR (WITH U1-125 SLM3 HANDSET)

Heatpump wiring diagram for MDB 125DR/MMC 125DR units with specific controller.

MODEL : MDB 150DR vs. MMC 150DR (WITH U1-125 SLM3 HANDSET)

Heatpump wiring diagram for MDB 150DR/MMC 150DR units with specific controller.

MODEL : MDB 150DR2 vs. MMC 075DR x 2

Heatpump wiring diagram for MDB 150DR2/MMC 075DR x 2 units with sequential controller.

MDB 200DR2 vs. MMC 100DR x 2

Heatpump wiring diagram for MDB 200DR2/MMC 100DR x 2 units with sequential controller.

MDB 250DR2 vs. MMC 125DR x 2

Heatpump wiring diagram for MDB 250DR2/MMC 125DR x 2 units with sequential controller.

MODEL : MDB 300DR2 vs. MMC 150DR x 2 (WITH SEQUENTIAL CONTROLLER)

Heatpump wiring diagram for MDB 300DR2/MMC 150D x 2 units with sequential controller.

MODEL : MDB 400DR4 vs. MMC 100DR x 4

Heatpump wiring diagram for MDB 400DR4/MMC 100DR x 4 units with sequential controller.

MDB 500DR4 vs. MMC 125DR x 4 WITH SEQUENTIAL CONTROLLER

Heatpump wiring diagram for MDB 500DR4/MMC 125DR x 4 units with sequential controller.

Refrigerant Circuit Diagram

MODEL : MMC 075D/100D/125D/150D

Refrigerant circuit diagram for MMC 075D/100D/125D/150D outdoor units.

MODEL : MLC 061C

Refrigerant circuit diagram for MLC 061C outdoor units.

MODEL : MMC 075DR/100DR/125DR/150DR (R22) M4MC 75DR/100DR/125DR/150DR (R407C)

Refrigerant circuit diagram for MMC DR series (R22) and M4MC DR series (R407C).

Installation (Indoor)

Installation (Outdoor)

LOCATION FOR INSTALLATION OF THE CONDENSING UNITS

VACUUMING AND CHARGING

GUIDELINES OF FIELD-CHARGING AIR CONDITIONING SYSTEMS WITH SCROLL COMPRESSORS

FIELD-CHARGING – SOME PRECAUTION POINTS

Precautions for scroll compressors, volumetric efficiency, vacuum, lubrication, and temperature damage.

CHARGE LIMITS

CHARGING PROCEDURES - SINGLE PHASE COMPRESSORS

Operation

ELECTRICAL CONNECTION

Refer to local electrical codes for wiring diameter and ensure compliance.

GENERAL PRECAUTION

OPERATIONAL CHECK

SYSTEM REFRIGERANT CHARGE LEVEL GUIDELINES

CAUTION FOR USE

Special Precautions For R407c

3) Characteristic

5) Handling And Installation Guidelines

Servicing And Maintenance

MAINTENANCE

Troubleshooting

1. Fan does not work

2. Fan works, but compressor does not work

3. Both fan and compressor does not work

4. Air-conditioner works but cooling not satisfactory

No Cooling

Troubleshooting flowchart for scenarios where the unit does not cool.

Insufficient Cooling

Troubleshooting flowchart for insufficient cooling issues.

High Discharge Pressure

Troubleshooting flowchart for issues related to high discharge pressure.

Low Discharge Pressure

Troubleshooting flowchart for issues related to low discharge pressure.

High Suction Pressure

Troubleshooting flowchart for issues related to high suction pressure.

Low Suction Pressure

Troubleshooting flowchart for issues related to low suction pressure.

Noisy Operation

Troubleshooting flowchart for identifying and resolving noisy operation.

Related product manuals

McQuay MMC100D User Manual

Table of Contents

Questions and Answers:

McQuay MMC100D Specifications

Summary

General Specifications

Safety Controls

Specifications

Cooling only 50Hz (R22)

Heatpump 50Hz (R22)

Cooling only 50Hz (R407C)

Cooling only 220V – 60Hz (R22)

Cooling only 460V – 60Hz (R22)

Performance Tables

R22 50Hz COOLING CAPACITY

Operating Range

Cooling only

Heat pump

Wiring Diagrams (Cooling)

MODEL : MDB 075D vs MMC 075D (WITH U1.4 MAINBOARD AND SLM3 HANDSET)

MODEL : MDB 100D vs MMC 100D (WITH U1.4 MAINBOARD AND SLM3 HANDSET)

MODEL : MDB 125D vs. MMC 125D ( WITH U1-125 MAINBOARD AND SLM3 HANDSET )

MODEL : MDB 150D vs. MMC 150D (WITH U1-125 MAINBOARD AND SLM3 HANDSET)

MODEL : MDB 150D2 vs. MMC 075D x 2

MDB 200D2 vs. MMC 100D x 2

MDB 250D2 vs. MMC 125D x 2

MODEL : MDB 300D2 vs. MMC 150D x 2 (WITH SEQUENTIAL CONTROLLER)

MODEL : MDB 400D4 vs. MMC 100D x 4

MDB 500D4 vs. MMC 125D x 4 WITH SEQUENTIAL CONTROLLER

Wiring Diagrams (Heatpump)

MODEL : MDB 075DR vs. MMC 075DR (WITH U1.4 / SLM3 HANDSET)

MODEL : MDB 100DR vs. MMC 100DR (WITH U1.4 / SLM3 HANDSET)

MODEL : MDB 125DR vs. MMC 125DR (WITH U1-125 SLM3 HANDSET)

MODEL : MDB 150DR vs. MMC 150DR (WITH U1-125 SLM3 HANDSET)

MODEL : MDB 150DR2 vs. MMC 075DR x 2

MDB 200DR2 vs. MMC 100DR x 2

MDB 250DR2 vs. MMC 125DR x 2

MODEL : MDB 300DR2 vs. MMC 150DR x 2 (WITH SEQUENTIAL CONTROLLER)

MODEL : MDB 400DR4 vs. MMC 100DR x 4

MDB 500DR4 vs. MMC 125DR x 4 WITH SEQUENTIAL CONTROLLER

Refrigerant Circuit Diagram

MODEL : MMC 075D/100D/125D/150D

MODEL : MLC 061C

MODEL : MMC 075DR/100DR/125DR/150DR (R22) M4MC 75DR/100DR/125DR/150DR (R407C)

Installation (Indoor)

Installation (Outdoor)

LOCATION FOR INSTALLATION OF THE CONDENSING UNITS

VACUUMING AND CHARGING

GUIDELINES OF FIELD-CHARGING AIR CONDITIONING SYSTEMS WITH SCROLL COMPRESSORS

FIELD-CHARGING – SOME PRECAUTION POINTS

CHARGE LIMITS

CHARGING PROCEDURES - SINGLE PHASE COMPRESSORS

Operation

ELECTRICAL CONNECTION

GENERAL PRECAUTION

OPERATIONAL CHECK

SYSTEM REFRIGERANT CHARGE LEVEL GUIDELINES

CAUTION FOR USE

Special Precautions For R407c

3) Characteristic

5) Handling And Installation Guidelines

Servicing And Maintenance

MAINTENANCE

Troubleshooting

1. Fan does not work

2. Fan works, but compressor does not work

3. Both fan and compressor does not work

4. Air-conditioner works but cooling not satisfactory

No Cooling

Insufficient Cooling

High Discharge Pressure

Low Discharge Pressure

High Suction Pressure

Low Suction Pressure

Noisy Operation

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