High current – compressor trips

Questions & AnswersCategory: GeneralHigh current – compressor trips
Guest Staff asked 5 days ago

2 day ago my plant air compressor trip on high operating current show on fault alarm.Which never happen before.

I do a reset it start back on idle the running current is normal went the SCREW air end start to load .

I can see my clamp on ampere meter going up above the normal running current. I stop the air compressor check the incoming and outgoing power supply voltage all normal.

If I run the air compressor with air discharge pipe disconnect to reciver tank it run fine. Once, I run with discharge pipe connect to reciver tank as the air pressure built up in reciver tank before reach cutout point high current will accord .

Please advise me what is the possible issue on my air compressor your professional advise is appreciated .

Thank and best regard

1 Answers
Cas Staff answered 5 days ago

Hi Mr. Leong,

You did the most important tests already, great. It looks like the overcurrent is related to the outlet pressure of the compressor.

Please check your oil separator. When was it last changed?

The oil separator is like a big filter and it removes the oil from the compressed air.

But it slowly gets dirty, and it it ‘saturates’ with oil. This creates a restriction for the air flow. A pressure drop is the results.

Since the compressor regulates it’s outlet pressure, this means that the pressure before the oil separator will increase. If this increase (pressure drop) becomes too big, some things can happen:

* oil separator implodes (all oil is send down the compressed air pipes)
* motor overload

So please check your oil separator. It could be that compressor outlet pressure is 7 bar, but the pressure before the separator is 8 or 9 bar!

Other thing that could be wrong: voltage drop – you already measured the voltage before and after running. But please check DURING running. If there’s a bad connection somewhere, or the cables or too small a drop in voltage will occur, which can overload the motor.

Hope this helps! Would love to hear how this works out..

Cas