McQuay MDB100B User Manual (English)

Questions and Answers:

J
johnsonsarahAug 9, 2025
Why is my McQuay MDB100B not cooling properly?
- C
  Charles NorrisAug 9, 2025
  If your McQuay Air Conditioner is running but not cooling effectively, several factors could be the cause. First, make sure the thermostat isn't set too high; try resetting it. Ensure all doors and windows are completely closed. If these steps don't help, there might be an obstruction blocking the unit's inlet or outlet; remove any objects you find. For issues such as a dirty condenser coil or insufficient refrigerant, it is best to contact your local dealer.
J
Jennifer MartinezAug 16, 2025
What to do if both fan and compressor on my McQuay MDB100B don't work?
- C
  Cheryl ColeAug 16, 2025
  If neither the fan nor the compressor is working on your McQuay Air Conditioner, there are a few things you can check. First, there may be a power failure; the unit should resume operation when the power supply is restored. Also, the starter may have tripped; try resetting it. Finally, inspect the fuse in the power switch or operating unit and replace it if it's blown.
T
Tiffany Smith PhDAug 25, 2025
How to fix a McQuay MDB100B Air Conditioner when the fan is not working?
- K
  Kelsey KnightAug 25, 2025
  If the fan on your McQuay Air Conditioner isn't working, start by checking the power supply. If the power supply is fine, the issue might be a faulty fan capacitor or fan motor, in which case you should contact your local dealer. Another potential cause is a faulty switch, which would need to be changed.
B
Bonnie Gilbert DVMAug 31, 2025
What to do if McQuay MDB100B Air Conditioner fan works, but the compressor doesn't?
- E
  Emily LeeSep 1, 2025
  If the fan on your McQuay Air Conditioner is working, but the compressor isn't, there are a few potential reasons. First, the thermostat setting might be too high; try resetting it. It's also possible that the dual pressure control has tripped; in this case, reset the pressure control. For compressor or compressor contractor issues, contact your local dealer.

McQuay MDB100B Specifications

General

Brand	McQuay
Model	MDB100B
Category	Air Conditioner
Language	English

Summary

General Specifications and Operation

General Unit Specifications

Details casing, coils, fan, motor, compressor, and safety controls.

Operating Guide

Instructions for operating the unit, including modes, settings, and timers.

Model Specifications and Performance Data

Cooling Only Specifications

Detailed technical specifications for cooling-only models.

Heatpump Specifications

Detailed technical specifications for heatpump models.

Heatpump Specifications - 220V-60 Hz

Specific technical data for heatpump units operating at 220V-60Hz.

Heatpump Specifications - 460V-60 Hz

Specific technical data for heatpump units operating at 460V-60Hz.

Performance Characteristics - Cooling

Detailed performance data for various models under different operating conditions.

Performance Characteristics - Heatpump

Performance data for heatpump models under various operating conditions.

Power Table Data

Tables detailing power consumption (watts) for various models.

Drive Package Selection Example

A step-by-step guide illustrating how to select appropriate drive package components.

Blower Performance Curves

Graphical representation of blower performance characteristics for different models.

Unit Outlines and Dimensions

Indoor Unit Dimensions

Provides detailed dimensional drawings for indoor units.

Outdoor Unit Dimensions

Provides detailed dimensional drawings for outdoor units.

Wiring Diagrams

Cooling Wiring Diagrams

Electrical wiring diagrams for cooling operation of various unit combinations.

MDB 075B – MMC 075C Cooling Wiring Diagram

Wiring diagram for MDB 075B indoor and MMC 075C outdoor units in cooling mode.

MDB 075B – MMC 075B Cooling Wiring Diagram

Wiring diagram for MDB 075B indoor and MMC 075B outdoor units in cooling mode.

MDB 100B – MMC 100B / 100C Cooling Wiring Diagram

Wiring diagram for MDB 100B indoor and MMC 100B/100C outdoor units in cooling mode.

MDB 075B (U1.4 CCT) / MMC 075B (Phase Protector) Cooling Wiring Diagram

Wiring diagram for MDB 075B (U1.4 CCT) / MMC 075B (Phase Protector) units.

MDB 075B (U1.4 CCT) / MMC 075C (Phase Protector) Cooling Wiring Diagram

Wiring diagram for MDB 075B (U1.4 CCT) / MMC 075C (Phase Protector) units.

MDB 100B (U1.4 CCT) / MMC 100B (Phase Protector) Cooling Wiring Diagram

Wiring diagram for MDB 100B (U1.4 CCT) / MMC 100B (Phase Protector) units.

MDB 125C (U125-SB) / MMC 125B (Phase Protector) Cooling Wiring Diagram

Wiring diagram for MDB 125C (U125-SB) / MMC 125B (Phase Protector) units.

MDB 150C1 (U125-SB) / MMC 150C (Phase Protector) Cooling Wiring Diagram

Wiring diagram for MDB 150C1 (U125-SB) / MMC 150C (Phase Protector) units.

MDB 150B2 / MMC 075C x 2 Cooling Wiring Diagram

Wiring diagram for MDB 150B2 indoor and MMC 075C x 2 outdoor units.

MDB 150B2/200B2/250B2 / MMC x2 Cooling Wiring Diagram

Wiring diagram for MDB 150B2/200B2/250B2 indoor and multiple MMC outdoor units.

MDB 300B2 / MMC 150C x 2 Cooling Wiring Diagram

Wiring diagram for MDB 300B2 indoor and MMC 150C x 2 outdoor units.

MDB 300B3 & 350B3 / MMC x3 & (MMC100B/C x 1 + MMC125B x 2) Cooling Wiring Diagram

Wiring diagram for MDB 300B3/350B3 indoor and multiple MMC outdoor units.

MDB 450B3 / MMC 150C x 3 Cooling Wiring Diagram

Wiring diagram for MDB 450B3 indoor and MMC 150C x 3 outdoor units.

MDB 400B4 & 500B4 / MMC x4 Cooling Wiring Diagram

Wiring diagram for MDB 400B4/500B4 indoor and multiple MMC outdoor units.

MDB 600B4 / MMC 150C x 4 Cooling Wiring Diagram

Wiring diagram for MDB 600B4 indoor and MMC 150C x 4 outdoor units.

MDB 750B5 / MMC 150C x 5 Cooling Wiring Diagram

Wiring diagram for MDB 750B5 indoor and MMC 150C x 5 outdoor units.

Heatpump Wiring Diagrams

Electrical wiring diagrams for heatpump operation of various unit combinations.

Indoor Export Models Heatpump Wiring Diagrams

Wiring diagrams for export models of MDB 075/100BR and MDB 125CR indoor units.

MDB 150/200/250 BR2 (Export) Heatpump Wiring Diagram

Wiring diagrams for export MDB 150/200/250 BR2 indoor units.

MDB 300/350 BR3 (Export) Heatpump Wiring Diagram

Wiring diagrams for export MDB 300/350 BR3 indoor units.

MDB 400/500 BR4 (Export) Heatpump Wiring Diagram

Outdoor Export Wiring Diagrams

Wiring diagrams for export outdoor units.

MMC 075CR / 100BR (Version 1) Wiring Diagram

MMC 125BR (Export) (Version 1) Wiring Diagram

MMC 075CR / 100BR (Version 2) Heatpump Wiring Diagram

MMC 125BR (Version 2) Heatpump Wiring Diagram

MDB 075BR (U1.4 CCT) / MMC 075CR (Version 3) Heatpump Wiring Diagram

MDB 100BR (U1.4 CCT) / MMC 100BR (Version 3) Heatpump Wiring Diagram

MDB 125CR (U125-SB) / MMC 125BR (Phase Protector) Heatpump Wiring Diagram

MDB 150/200BR2 (Sequential Controller) / MMC 075CR x 2 or MMC100BR x 2 (Phase Protector) Heatpump Wiring Diagram

MDB 250BR2 (Sequential Controller) / MMC 125BR x 2 (Phase Protector) Heatpump Wiring Diagram

MDB 300 BR3 (Sequential Controller) / MMC 100BR x 3 (Phase Protector) Heatpump Wiring Diagram

MDB 350 BR3 (Sequential Controller) / MMC 100BR x 1 or MMC125BR x 2 (Phase Protector) Heatpump Wiring Diagram

MDB 400 BR4 (Sequential Controller) / MMC 100BR x 4 (Phase Protector) Heatpump Wiring Diagram

MDB 500 BR4 (Sequential Controller) / MMC 125BR x 4 (Phase Protector) Heatpump Wiring Diagram

Refrigerant Circuit Diagrams

Installation Procedures

Indoor Unit Installation Procedures

Guidance for the proper installation of indoor units.

Electrical Connection Guidelines

Essential precautions for safe and correct electrical wiring.

Outdoor Unit Installation Procedures

Guidance for the proper installation of outdoor condensing units.

Outdoor Unit Location Requirements

Criteria for selecting an optimal location for condensing units to ensure performance.

Field Piping Guidelines

Recommendations for field piping to ensure satisfactory refrigerant cycle operation.

Maximum Pipe Length and Bends Limits

Vacuuming and Charging Procedures

Essential steps for vacuuming the system and charging refrigerant.

System Refrigerant Charge Guidelines

Recommended refrigerant charge levels based on model and pipe size.

Cooling Only Refrigerant Charge Data

Heatpump Refrigerant Charge Guidelines

Recommended refrigerant charge levels for heatpump models.

Heatpump Charge Information by Model

Maintenance, Operation, and Troubleshooting

Servicing and Maintenance Guide

General procedures and recommendations for maintaining the unit.

Operation Guide

Instructions for operating the air conditioning system.

Sequential Controller Model Selection

Instructions for configuring the controller based on unit model and features.

Sequential Controller Block Diagram

Troubleshooting Guide

Common issues, probable causes, and suggested solutions for air conditioner malfunctions.

Troubleshooting - No Cooling Issues

Flowchart for diagnosing and resolving "No Cooling" issues.

Compressor Not Starting Troubleshooting

Troubleshooting steps when the compressor fails to start.

Troubleshooting - Insufficient Cooling Issues

Flowchart for diagnosing and resolving "Insufficient Cooling" problems.

Troubleshooting - High Discharge Pressure Issues

Flowchart for diagnosing and resolving "High Discharge Pressure" issues.

Troubleshooting - Low Discharge Pressure Issues

Flowchart for diagnosing and resolving "Low Discharge Pressure" issues.

Troubleshooting - High Suction Pressure Issues

Flowchart for diagnosing and resolving "High Suction Pressure" issues.

Troubleshooting - Low Suction Pressure Issues

Flowchart for diagnosing and resolving "Low Suction Pressure" issues.

Troubleshooting - Noisy Operation Issues

Flowchart for diagnosing and resolving "Noisy Operation" issues.

Part Lists

Indoor Unit Parts List

Exploded views and part numbers for indoor unit components.

Vertical Air Discharge Indoor Unit Parts List

Exploded views and part numbers for vertical air discharge indoor units.

Heatpump Indoor Unit Parts

Exploded views and part numbers for indoor heatpump units.

Vertical Air Discharge Outdoor Unit Parts

Exploded views and part numbers for vertical air discharge outdoor units.

Related product manuals

McQuay MDB100B User Manual

Table of Contents

Questions and Answers:

McQuay MDB100B Specifications

Summary

General Specifications and Operation

General Unit Specifications

Operating Guide

Model Specifications and Performance Data

Cooling Only Specifications

Heatpump Specifications

Heatpump Specifications - 220V-60 Hz

Heatpump Specifications - 460V-60 Hz

Performance Characteristics - Cooling

Performance Characteristics - Heatpump

Power Table Data

Drive Package Selection Example

Blower Performance Curves

Unit Outlines and Dimensions

Indoor Unit Dimensions

Outdoor Unit Dimensions

Wiring Diagrams

Cooling Wiring Diagrams

MDB 075B – MMC 075C Cooling Wiring Diagram

MDB 075B – MMC 075B Cooling Wiring Diagram

MDB 100B – MMC 100B / 100C Cooling Wiring Diagram

MDB 075B (U1.4 CCT) / MMC 075B (Phase Protector) Cooling Wiring Diagram

MDB 075B (U1.4 CCT) / MMC 075C (Phase Protector) Cooling Wiring Diagram

MDB 100B (U1.4 CCT) / MMC 100B (Phase Protector) Cooling Wiring Diagram

MDB 125C (U125-SB) / MMC 125B (Phase Protector) Cooling Wiring Diagram

MDB 150C1 (U125-SB) / MMC 150C (Phase Protector) Cooling Wiring Diagram

MDB 150B2 / MMC 075C x 2 Cooling Wiring Diagram

MDB 150B2/200B2/250B2 / MMC x2 Cooling Wiring Diagram

MDB 300B2 / MMC 150C x 2 Cooling Wiring Diagram

MDB 300B3 & 350B3 / MMC x3 & (MMC100B/C x 1 + MMC125B x 2) Cooling Wiring Diagram

MDB 450B3 / MMC 150C x 3 Cooling Wiring Diagram

MDB 400B4 & 500B4 / MMC x4 Cooling Wiring Diagram

MDB 600B4 / MMC 150C x 4 Cooling Wiring Diagram

MDB 750B5 / MMC 150C x 5 Cooling Wiring Diagram

Heatpump Wiring Diagrams

Indoor Export Models Heatpump Wiring Diagrams

MDB 150/200/250 BR2 (Export) Heatpump Wiring Diagram

MDB 300/350 BR3 (Export) Heatpump Wiring Diagram

MDB 400/500 BR4 (Export) Heatpump Wiring Diagram

Outdoor Export Wiring Diagrams

MMC 075CR / 100BR (Version 1) Wiring Diagram

MMC 125BR (Export) (Version 1) Wiring Diagram

MMC 075CR / 100BR (Version 2) Heatpump Wiring Diagram

MMC 125BR (Version 2) Heatpump Wiring Diagram

MDB 075BR (U1.4 CCT) / MMC 075CR (Version 3) Heatpump Wiring Diagram

MDB 100BR (U1.4 CCT) / MMC 100BR (Version 3) Heatpump Wiring Diagram

MDB 125CR (U125-SB) / MMC 125BR (Phase Protector) Heatpump Wiring Diagram

MDB 150/200BR2 (Sequential Controller) / MMC 075CR x 2 or MMC100BR x 2 (Phase Protector) Heatpump Wiring Diagram

MDB 250BR2 (Sequential Controller) / MMC 125BR x 2 (Phase Protector) Heatpump Wiring Diagram

MDB 300 BR3 (Sequential Controller) / MMC 100BR x 3 (Phase Protector) Heatpump Wiring Diagram

MDB 350 BR3 (Sequential Controller) / MMC 100BR x 1 or MMC125BR x 2 (Phase Protector) Heatpump Wiring Diagram

MDB 400 BR4 (Sequential Controller) / MMC 100BR x 4 (Phase Protector) Heatpump Wiring Diagram

MDB 500 BR4 (Sequential Controller) / MMC 125BR x 4 (Phase Protector) Heatpump Wiring Diagram

Refrigerant Circuit Diagrams

Installation Procedures

Indoor Unit Installation Procedures

Electrical Connection Guidelines

Outdoor Unit Installation Procedures

Outdoor Unit Location Requirements

Field Piping Guidelines

Maximum Pipe Length and Bends Limits

Vacuuming and Charging Procedures

System Refrigerant Charge Guidelines

Cooling Only Refrigerant Charge Data

Heatpump Refrigerant Charge Guidelines

Heatpump Charge Information by Model

Maintenance, Operation, and Troubleshooting

Servicing and Maintenance Guide

Operation Guide

Sequential Controller Model Selection

Sequential Controller Block Diagram

Troubleshooting Guide

Troubleshooting - No Cooling Issues

Compressor Not Starting Troubleshooting

Troubleshooting - Insufficient Cooling Issues