Need Help for a Copeland Compressor

[Mr JamCoool]

Hey Everyone,I am working on a Hussman rack system seven (7) compressors, the number five (5) Compressor Oil failure light keeps coming on like every 5 mintues and the compressor is not running , however the suction is still wet and slightly cold.I have reset the Oil faliure switch , which is a Johnson Controls switch. but the indicator comes back on.

[wambat]

This could be refrigerant migration when compressor is off. If it has an oil heater you should ck it out.

[superswill]

Hey Everyone,I am working on a Hussman rack system seven (7) compressors, the number five (5) Compressor Oil failure light keeps coming on like every 5 mintues and the compressor is not running , however the suction is still wet and slightly cold.I have reset the Oil faliure switch , which is a Johnson Controls switch. but the indicator comes back on.

then you have a problem,is the compressor low on oil or the switch faulty

[GXMPLX]

If it happens so often it should be very easy to diganose hooking calibrated gages instead of the oil safety and whatching differential pressure.

Also you can bench test the oil switch.

What does the sight glass show?

[750 Valve]

sounds like an electrical/wiring issue, could possibly be that the oil safety is getting power but the control circuit will not pull the contactor in due to another mechanical safety holding it out, usually a sign of a poorly wired control circuit or a comp with the 3 phase tripped. Is the comp contactor pulled in when the fault light is on? If it is pulled in and as you say the comp isn't actually running, then does it have power available to the compressor motor (3 phase)?

[Porkington]

People asking this sort of queston with this level of information really do worry me.

[abet_meneses]

jamcool,

1.check oil pump pressure,it should be at least 9psi above crankcase pressure lower differential other than that will tripped oil fail control.

2.replace oil,clean oil filters and energize crankcase heater will prevent nuissance tripping .
hope it helps.

[coolhibby1875]

if your compressor is not running it sounds like the nrv (non return valve)on the discharge pipe next to the compressor is not seating lifting all the oil out the body so when the compressor starts there is no oil and the comp trips out.

[PaulZ]

If the oil failure keeps coming on every 5 mins and the compressor is not running I think it would be an electrical fault and I would do what 750 Valve has suggested.
If you can't find anything electrically wrong then start looking for a system or mechanical fault.
Paul

[GXMPLX]

If the oil failure keeps coming on every 5 mins and the compressor is not running I think it would be an electrical fault and I would do what 750 Valve has suggested.
If you can't find anything electrically wrong then start looking for a system or mechanical fault.
Paul

All posts have a good point but I would hook gages first. This will tell you inmediatelly if the problem is electrical or mechanical in nature.

[bukichu1]

I think that the oil filter is not clean , close the suction and discharge taps, release all the gas from the compressor and clean the oil filter....
If that doesnt work maybe the bearings are gone....

[casstrig]

I agree with 750 with the compressor off there is no differential pressure as it has equalised so the switch is not faulty in fact it should not even have power,check your circuit you probably have a welded contact on an auxillary contact or somthing else.

[5-STAR]

On a Hussmann rack the control circuit is seperate from the compressor. The compressor CB is tripped.