McQuay GZ 035AM - User Manual

Questions and Answers

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Theresa FosterAug 19, 2025
What to do if McQuay GZ 035AM Chiller compressor overloads or circuit breakers open?
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  uhornAug 19, 2025
  If the compressor overloads or circuit breakers open in your McQuay Chiller, it could be due to several reasons: * Low line voltage: Check the incoming voltage and report any issues to your electrical supplier. * High compressor amps: Identify the cause of the high amperage and correct it. * Loose power wiring: Tighten all connections. * High condenser pressures: Refer to the troubleshooting steps for high condenser pressure. * Single phasing: Replace the fuses or breaker.
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bradleysmithAug 22, 2025
Why is the discharge pressure high in my McQuay GZ 035AM Chiller?
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  Daniel AcostaAug 22, 2025
  High discharge pressure in your McQuay Chiller can stem from several factors: * Dirty condenser coils: Clean the coils. * Fan not operating: Check the fan motor, contactor, contactor coil, and fan pressure switch. Repair or replace any defective parts. * High ambient conditions: Compare the current conditions against the design conditions. * High return water temperature: Disable a compressor on each. * Overcharge of refrigerant: Remove the excessive amount of refrigerant. * Non-condensables in the system: Remove any non-condensable substances. * Discharge valve partially closed: Back seat the valve.
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John BarkerAug 25, 2025
How to fix low suction pressure in McQuay GZ 035AM?
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  debrajohnsAug 26, 2025
  Low suction pressure in your McQuay Chiller can be caused by: * Low refrigerant charge: Add refrigerant. * Defective expansion valve: Check its operation and repair or replace if needed. * Dirty filter drier: Replace the cores. * Reduced water flow: Increase water flow to the design GPM. * Hot gas bypass valve not set properly: Set the valve for a higher pressure. * Liquid line solenoid valve not opening: Repair or replace the valve. * Defective UNT controller: Check the water sensor, set point dial, and control band dial. Calibrate, repair, or replace the controller. * Gasket failure in evap head ring: Replace the gasket.
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Stephanie ChristensenAug 28, 2025
What causes high suction pressure in a McQuay GZ 035AM?
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  ethan21Aug 28, 2025
  High suction pressure in a McQuay Chiller can be attributed to: * Excessive load (high return water temperature): Check water flow and reduce the load. * Controller not staging up: Check the UNT controller and replace it if defective. * Compressor capacity reduced: Replace the compressor. * Association with high condenser pressure: Check the reasons for high condenser pressure.
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Cameron PatrickAug 31, 2025
Why is the discharge pressure low on my McQuay GZ 035AM Chiller?
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  sadkinsAug 31, 2025
  Low discharge pressure in your McQuay Chiller may be due to: * Fan contactor failed in closed position: Repair or replace the contactor. * Fan pressure switch defective: Replace the pressure switch. * Low ambient temps: Install SpeedTrol Kit. * Low on refrigerant charge: Add refrigerant. * Reduced chilled water flow: Check the flow and correct it. * No load and on hot gas bypass: Adjust the hot gas bypass to maintain a higher evaporator pressure.
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chad52Sep 3, 2025
What to do if freeze protection trips on McQuay Chiller?
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  Chad WallaceSep 3, 2025
  If the freeze protection trips on your McQuay Chiller, consider the following: * Pressure transducers defective: Compare the output to actual refrigerant pressures. * Low water flow: Check water GPM and correct. * Low loads / erratic water flow: Check pump operation, water strainer, and air handler control valves. * Controller stage timing: Check the timing and reset as necessary.
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Jessica DavisSep 6, 2025
Why is my McQuay Chiller compressor losing oil?
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  Lindsey WheelerSep 6, 2025
  Compressor oil loss in your McQuay Chiller could be due to: * Excessive refrigerant flood back: Check the TXV and repair or replace it. * Defective crankcase heater: Replace the heater. * Low refrigerant charge: Add refrigerant. * Hot gas bypass not set properly: Increase hot gas flow.
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Mark HerreraSep 9, 2025
What causes erratic loading and unloading in McQuay Chiller?
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  Danielle RobertsonSep 10, 2025
  Erratic loading and unloading in your McQuay Chiller can result from: * Erratic chilled water flow: Check for reasons and correct. * Erratic system load: Check water flow control valve operation. * Bad water sensor: Replace the sensor. * Reset function calibration: Re-calibrate. * Defective UNT controller: Replace the controller.
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charleswrightSep 12, 2025
What to do if McQuay Chiller compressor internal motor switch open?
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  jsuttonSep 12, 2025
  If the internal motor switch is open in your McQuay Chiller compressor: * Compressor amps high: Refer to the troubleshooting steps for high compressor amps. * Motor winding damaged: Check motor winding resistance and replace if defective.
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Mr. Michael Johnson MDNov 15, 2025
How to troubleshoot a McQuay GZ 035AM Chiller compressor that won't start?
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  Julia BaileyNov 15, 2025
  If your McQuay Chiller compressor isn't running, there are several potential causes: * The main switch or circuit breakers might be open. Ensure the switch is closed. * A fuse could be blown. Inspect the electrical circuits and motor winding for shorts or grounds, which may indicate overloading. Replace the fuse or reset the breakers after fixing any faults. * Thermal overloads may have tripped. These are auto-reset, so monitor the unit closely when it restarts. * There may be a defective contactor or coil. Repair or replace as needed. * Safety devices may have shut down the system. Identify the type and cause of the shutdown, and correct it before resetting the safety. * The system may not require cooling. Wait for a load. * The liquid line solenoid may not be opening. Repa...

McQuay GZ 035AM Specifications

General

Model	GZ 035AM
Category	Chiller
Cooling Capacity	35 kW
Refrigerant Type	R410A
Sound Pressure Level	65 dB(A)
Dimensions (LxWxH)	1200 x 800 x 1200 mm
Power Supply	380-415V/3Ph/50Hz