EasyManua.ls Logo

McQuay ACZ 025A - User Manual

McQuay ACZ 025A
48 pages
Save Page as PDF
Print Icon
To Next Page IconTo Next Page
To Next Page IconTo Next Page
Loading...
Installation, Operation and Maintenance Manual
IOMM ACZ1
Group:
Chiller
Part Number
: 330262002
Effective:
December 2001
Supersedes:
New
Air-Cooled Scroll Condensing Units
ACZ 010A – ACZ 039A
10 to 43 Tons, 35 to 150 kW
R-22, 60 Hertz

Table of Contents

Questions and Answers

  • J
    jennifer88Aug 17, 2025
    What to do if the McQuay Heat Pump compressor will not run?
    • J
      Joshua CraigAug 17, 2025
      If the McQuay Heat Pump compressor will not run, first ensure the main switch is closed. Check for blown fuses or open breakers, inspecting electrical circuits and motor windings for shorts, overloads, and loose connections; replace the fuse or reset the breaker if necessary. Also, check if thermal overloads have tripped (they auto reset). Inspect the contactor or coil for defects and repair or replace if needed. Determine if a protection device has shut the system off and correct the cause. If no cooling is required, the compressor should start on a call for cooling. Check if the liquid line solenoid will not open and repair or replace the coil if needed. Inspect the motor for open or short circuits, or burnout. Finally, check all wire junctions and tighten all terminals.
  • P
    Patricia AdamsAug 19, 2025
    What to do if my McQuay ACZ 025A Heat Pump has high discharge pressure?
    • G
      gonzalezstaceyAug 20, 2025
      If your McQuay Heat Pump has high discharge pressure, it could be due to several reasons. First, there might be noncondensables in the system, which should be removed using authorized procedures. Another cause could be a refrigerant overcharge, so remove the excess. Check if the fan is running and inspect the electrical circuit. Dirty condenser coils can also cause this issue, so clean the coil. Lastly, the FanTrol might be out of adjustment, so adjust the FanTrol setting.
  • J
    Jake DixonAug 23, 2025
    Why is my McQuay ACZ 025A Heat Pump compressor noisy or vibrating?
    • J
      joycewagnerAug 23, 2025
      If your McQuay Heat Pump compressor is noisy or vibrating, it may be due to refrigerant flooding the compressor, so check the expansion valve setting. Another cause could be improper line support, in which case you should relocate or add supports. Finally, the compressor might be worn, requiring replacement.
  • M
    Michael BrownAug 26, 2025
    What causes motor overload relays to open or blown fuses in McQuay ACZ 025A?
    • C
      christopher11Aug 26, 2025
      Motor overload relays opening or blown fuses in your McQuay Heat Pump can be caused by several factors. These include: 1. Low voltage during high loads, in which case you should check the supply voltage. 2. Defective or grounded motor wiring, requiring you to replace the compressor. 3. Loose power wiring, so check all connections and tighten them. 4. High condensing temperature (see steps for high discharge pressure). 5. Unbalanced voltage, so check the voltage and contact the power company.
  • O
    Olivia AdamsAug 28, 2025
    What to do if my McQuay ACZ 025A has low suction pressure?
    • L
      Louis ConwayAug 28, 2025
      If your McQuay Heat Pump has low suction pressure, it could be due to a lack of refrigerant, so check for leaks and repair and replace the refrigerant. Another cause could be a dirty evaporator, which needs to be cleaned chemically. A clogged filter-drier can also cause this, so replace it. Additionally, the expansion valve might be malfunctioning; check and adjust for proper superheat. Low condensing temperature can also be a factor; check discharge pressure control settings.
  • T
    Taylor PerkinsAug 30, 2025
    Why is my McQuay ACZ 025A Heat Pump's compressor losing oil?
    • D
      Dana GonzalesAug 31, 2025
      If your McQuay Heat Pump's compressor is losing oil, it could be due to a lack of refrigerant, so check for leaks and repair them. Another cause could be suction superheat being too high, so adjust the superheat. Lastly, the crankcase heater might be burned out, requiring replacement.
  • T
    Thomas GonzalezSep 3, 2025
    What causes low discharge pressure in a McQuay ACZ 025A Heat Pump?
    • S
      Shelby RiceSep 3, 2025
      Low discharge pressure in a McQuay Heat Pump can be caused by a faulty condenser control, so check the condenser control operation. It can also be caused by a low refrigerant charge, so check for leaks and add refrigerant. Another possible cause is low suction pressure; see the low suction pressure steps.
  • M
    Marvin ClarkSep 5, 2025
    What causes high suction pressure in a McQuay Heat Pump?
    • L
      Lisa SantosSep 5, 2025
      High suction pressure in a McQuay Heat Pump can be caused by an excessive load, so reduce the load or add capacity. It may also be caused by the expansion valve overfeeding, so check the remote bulb and regulate superheat.
  • R
    Robert McclainSep 8, 2025
    What causes a McQuay ACZ 025A Heat Pump unit to not load or unload?
    • K
      Katelyn PerezSep 8, 2025
      If a McQuay Heat Pump unit will not load or unload, it could be due to a faulty controller sensor or a broken wire, requiring replacement. Another cause could be stages not set for the application, so adjust the thermostat setting.
  • A
    Alicia CarrilloSep 12, 2025
    Why does my McQuay ACZ 025A Heat Pump have a short load/unload interval?
    • T
      Timothy BradleySep 12, 2025
      If your McQuay Heat Pump has a load/unload interval that is too short, it could be due to an erratic thermostat, in which case you should replace it. Another cause could be insufficient water flow, so adjust the flow.

Summary

Piping Systems

Refrigerant Piping

Recommendations for sizing and routing suction and liquid lines for optimal performance.

Electrical and Physical Data

Electrical Data and Wiring

Field wiring, ampacity, fuse sizes, and electrical notes for unit installation.

Control System Overview

Control Center and Start-up

Sequence of Operation

Details unit operation, alarms, fan control, and shutdown sequences.

MicroTech II Controller Functions

Controller Overview and Features

Alarms, Modes, and Unit Control

Information on alarms, unit enable, operating modes, and compressor/fan staging.

Using the Controller Interface

Navigation and Setpoint Adjustment

Steps for navigating menus and modifying setpoints using the controller interface.

Parameter Configuration

Service Procedures

Key Components Service

Troubleshooting

Problem Diagnosis and Solutions

Comprehensive chart for diagnosing and correcting common unit problems and alarms.

McQuay ACZ 025A Specifications

General IconGeneral
Model NumberACZ 025A
CategoryHeat Pump
BrandMcQuay
Phase1
RefrigerantR-410A
Heating Capacity26000 BTU
Voltage208/230V

Related product manuals