Liebert Prop Fan Condensing Unit

Questions and Answers

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Brenda TaylorAug 19, 2025
Why is the Liebert Fan compressor motor protectors tripping or cycling?
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  eharrisAug 19, 2025
  The Liebert Fan compressor motor protectors might be tripping or cycling due to several reasons. High discharge pressure could be the cause, so check for a blocked condenser fan or coil. High suction temperature is another possibility; in this case, inspect the expansion valve and hot gas bypass valve settings, and check the liquid quenching valve operation. Also, inspect for loose power or control circuit wiring connections. Finally, a defective motor can cause this issue; check for a motor ground or short, and replace the compressor if either condition is found.
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Laura GreenAug 22, 2025
What causes high discharge pressure in a Liebert Prop Condensing Unit Fan?
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  martinshieldsAug 22, 2025
  High discharge pressure in a Liebert Fan can be caused by insufficient airflow across the condenser coil. Check the fan operation and remove any debris from the coil and air inlets to ensure proper airflow. Another potential cause is a high refrigerant charge, so it is important to check the refrigerant charge.
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Jane ReynoldsAug 26, 2025
What to do if the Liebert Prop Condensing Unit compressor is noisy?
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  Timothy SteeleAug 26, 2025
  If the Liebert Fan compressor is noisy, it could be due to loose compressor or piping support; tighten the clamps to secure them. Another possible cause is compressor rotation in the reverse direction; check for proper power phase wiring to the unit and to the compressor motor.
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Peter MacdonaldAug 28, 2025
Why is the Liebert Fan compressor cycling on locked rotor?
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  qwatsonAug 28, 2025
  If the Liebert Fan compressor cycles on a locked rotor, it could be due to low line voltage; check the line voltage and determine the location of the voltage drop. It could also be caused by a defective compressor motor; check for a motor winding short or ground. Single phasing could also be the culprit; check the voltage across all 3 legs at the contactor and correct the source of the problem.
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Matthew FrankAug 31, 2025
What causes low suction pressure and compressor cycling in a Liebert Prop Condensing Unit?
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  Angela StoneAug 31, 2025
  Low suction pressure and compressor cycling in a Liebert Fan can stem from several issues. Insufficient refrigerant in the system is a common cause; check for leaks, repair them, and add refrigerant as needed. A plugged filter drier can also lead to this problem; replace the filter drier. Improper superheat adjustment is another possibility; reset the expansion valve for 10-15°F (5.6 to 8.4°C) superheat at the evaporator. Lastly, a defective liquid line solenoid valve could be the cause; check the valve and coil, and replace if necessary.
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Abigail Wade DVMSep 3, 2025
Why Liebert Fan has low compressor capacity or no cooling?
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  cporterSep 3, 2025
  Low compressor capacity or no cooling in a Liebert Fan can arise from a defective liquid line solenoid valve; check the valve and coil, replacing if necessary. A plugged filter drier can also cause this; check the pressure drop across the filter drier and replace it if needed. Additionally, a low refrigerant charge might be the issue; check for normal system operating pressures, refer to abnormal pressure causes if applicable, and check for leaks. Maintaining the proper refrigerant charge is crucial, especially during low ambient operation.
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Mary ShawSep 6, 2025
What causes low discharge pressure in Liebert Prop Condensing Unit?
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  Christopher HunterSep 6, 2025
  Low discharge pressure in a Liebert Fan can be attributed to a faulty head pressure control valve; replace it if defective. It can also be caused by compressor rotation in the reverse direction; check for proper power phase wiring to the unit and to the compressor motor.
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kevin18Sep 9, 2025
What to do about pipe rattle in a Liebert Prop Condensing Unit Fan?
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  Brett FisherSep 9, 2025
  If you're experiencing pipe rattle in your Liebert Fan, check the pipe connections to ensure they are secure.
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gwilliamsSep 12, 2025
What causes a Liebert Fan compressor to run hot?
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  Sheila DiazSep 12, 2025
  A Liebert Fan compressor running hot can be due to a compression ratio that is too high. Check for normal system operating pressures and refer to abnormal pressure causes if applicable.
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Monica SanchezNov 15, 2025
What to do if the Liebert Fan unit will not start?
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  Christopher MooreNov 15, 2025
  If the Liebert Fan unit doesn't start, several issues could be the cause. First, check the voltage at the input terminal block to ensure the unit is receiving power. If there is no power, resolve the power supply issue. If there is power, it could be that the compressor contactor is not pulling in. Check for 24VAC ±2VAC at control connections 1 & 2. If there's no voltage, verify the control setting requires cooling. If voltage is present, the lockout relay might be energized; check for 24VAC at control connections 2 & 3. If voltage is present, refer to compressor high-discharge pressure/lockout relay. Also, the control voltage circuit breaker at the transformer in the evaporator module might be open; locate the short and reset the circuit breaker. Finally, the short cycle prevention contro...