York Compressor oil problem

[longfin]

Hi Guys
My customer has a Email York LCHD 55W . This compressor has a constant oil pressure 300 kpa until it unloads and then pressure drops about 20 kpa and becomes erratic. Gauge bounces and then loses oil pressure and stops. this takes about 3 minutes.
Any ideas?

[Grizzly]

Hi Longfin.
Does this chiller have a J style comp on it?
If it does.
There are many factors which could be producing these oil issues.
Some things to check would be the oil Temperature.
Does the comp run for long periods part loaded?
You could have a heavily blocked oil strainer.
Usually due to high ferrous and non ferrous particles in the sump.
One or more of the cylinder loading assembly seals could of failed.
You could have excessive wear internally.
Also what is the flow across the evaporator like?
The above are just a few options all of which are usually found with.
High running hours and infrequent service intervals.
Oh! what is the oil level in the sump?
Cheers Grizzly

[al]

As with Grizz

water flow is critical, then worry about compressor, blocked stainer, blocked loading assembly, oil level and return...

al

[longfin]

Thanks for your reply Grizzly, looks like the compressor needs a internal examination. I am not familiar with the j style compressor, and this compressor was bought second hand by the customer so who knows what application it was it used for before, but it is now used on high temperature rooms 10 degrees c, and not water chilling
The oil level in the sump is half of the higher sight glass. There are two sight glasses on the oil pump side of the compressor.
As for the flow across the evaporator, do you mean water flow? This set up is 2 evaporator coils which once again could have been taken off a faulty chiller and utelized the compressor for its present application
I will recomend a internal inspection.

[Grizzly]

Water flow equates to the pressure drop across the shell and tube evap.
2 evap coils = 2 circuits within the evap or are you saying the comp is hooked up to DX evaps?
Enjoy, it sounds as if you are up against it!
Grizzly

[licencetochill]

If its a J series compressor, id check the oil strainer mate.drop the oil,pop off an inspection panel and give it a good clean( they dont come out, so dont pull on it too hard!) id also check your suction filter, its a stainless mesh in behind the suction isolating valve.they would be the most common cause's.Oil pressure should be around 420-500 kpa

[GHAZ]

Hi normally the compressor needs oil pressure to load and if it has any mechanical faults it shows ,but losing oil pressure on unloading it doesnt seem right unless its oil temperature is too hot i,e above 70c and its thinning out,