synthetic oils

[bob2+1]

Hi first timer
I HAVE A REBUILT 6 CYLINDER COPELAND ON A CHILLER ,WITH CLEVAS 32 OIL IN IT ON R22 THE OIL LEAVES THE COMP WITHIN 5MINS & GOE'S OFF ON OIL PRESSURE SWITCH ONLY 1/2 A BAR OIL PRESSUIRE. HAS IT HAD THE WRONG OIL PUT IN IT

YOURS
BOB2+1

[Grizzly]

Hi Bob and welcome to the forum!

Basically clevas 32 may or may not be to thin.
I am more used to seeing Clavus 68 with R22.
Maybe some of the other Guys could advise on that?
Basically of you read the data via the link below that I have attached.
You will note that the oil diff can be set as low as 9psi.
With apparently oil pressures near to that being acceptable.
Anyway have a read and let us know what you think?
Grizzly
http://www.mediafire.com/?t01dbjyb9oy

[chemi-cool]

Hi Bob,
A common mistake among RE's is that oil just leaves the compressor.
The common problem is oil return to the compressor.

Oil circulate all the time in the system.

My thought is that liquid refrigerant from the chiller washed the oil out of the compressor and it is in the chiller.
In that case, I run the compressor with a little oil and let bring the oil back in normal working order.
If it doesn't return, than there is a problem that need to be looked after and be solved.

It has nothing to do with the type of oil.

[Magoo]

I agree with all the above comments, but would add that I would look at oil separator if it has one, and actual suction temp entering compressor for saturation, oil pump regulator, sump heaters and oil temps. Oil viscosity would consider manufactures specification would probably 68., like Suniso 4Gs for R22.
magoo

[GHAZ]

hi did you rebuilt the compressor or is it from a reman place,because if the compressor is pumping its oil out with in 5 minutes ,its bores are worn or the main bearing bearings are worn heavily because the oil pump is pumping the oil through the crank and straight into the winding section from there its going into the bores and out

[Shibhrac]

Compressor's crankcase should be kept warm during off cycle. If liquid refrigeran stayed in the compressor or liquid refrigerant is returned through suction port . This would dilute the oil and cause marginal lubrication and also allow most of the oil to leave the compressor, and would have to go through the complete system to get back to the compressor crankcase.

[powell]

If I read this correctly, the compressor starts and the oil disappears from the sight glass and the LOC cuts out.

Does the oil return after the compressor shuts down?

If so, you may have a pressurized crank which causes "blow by". This results from the compressor running hot, breaking down the oil and wearing out the internal components. The worn cylinder walls then bypass gas which pressurizes the crank due to the internal check valve between the crank and motor compartment closing. After it sits idle the check valve opens and the oil returns.

There is another valve in the crank called the Crankcase Ventilation Valve. When the crank is pressurized this valve opens to the suction chamber to relieve the pressure.

In a "blow by" situation the excess pressure built up in the crankcase may exceed the ability of the crankcase ventilating valve to vent the crankcase causing the check valve to close.

The oil pump is still picking up oil in the crank and pumping it through a drilled crank where it exits into the motor compartment.

Measure the crank pressure and the suction pressure and if there is a pressure difference of 2 lbs or more then this is your problem.

Replacing the compressor is the only solution if you have a worn compressor. Then you must find the reason for the overheating or it will happen again.

Here is a picture that might help.