What could be said about compressor condition if it's running current deviates from normal?

12 Apr '18, 06:51

April 12, 2018, 6:51 a.m.
KnowledgeBase's gravatar image


For equipment driven by an electric motor, such as compressors and pumps, the running current of a driving motor is good evaluation criteria for the overall unit condition.

1. Electric motor power (current) increased

  • a) Possible failure of the inlet/discharge (sticking) valve, the discharge pressure (especially of an intermediate stage) increases and compression ratio increases.
    Check the inlet/discharge valve of each stage and repair or replace.

  • b) Seizure of bearing, deterioration of grease or leakage.
    Repair or replace the bearing.

  • c) Seizure of piston.
    Check liner, rings and piston for wear, tear any other abnormalities.

2. Electric motor power (current) decreases

  • a) Failure of inlet/discharge valve (damaged).
    Volume efficiency decreases and as a result, air volume is reduced. 
Accompanied by the increased temperature of the stage as hot compressed air from the next stage leaks back. Check inlet/discharge valve and repair or replace.

  • b) Stage 1 inlet valve is stuck, thin air in sucked, discharge pressure is reduced, and air volume is reduced. Check the inlet/discharge valve and repair or replace

  • c) Inlet filter/silencer is abnormally contaminated. Clean or replace the inlet silencer.

  • d) Worn or damaged piston rings. Air leakage increases, thus reducing volume efficiency and also compression ratio. Overhaul compressor, replace the piston rings.

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12 Apr '18, 07:47

April 12, 2018, 7:47 a.m.
cheng's gravatar image

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