copeland discus oil pressure

[socotech]

Im almost positive loaded is de-energized.

Y2 doesn't connect straight to the unloader.

That said letting a thermostat load and unload a compressor is a bad idea.

Run that thing unloaded long enough and you'll be replacing it.

Does it have a Sentronic oil pressure unit ? Ive got two antique 30 ton york splits with new Copelands in them. Their not staged by the T-stats anymore.

Remember to use crankcase pressure to check oil pressure, not suction.

I used crankcase and oil pump to check pressure ( same place oil press safety is hooked to). I dont know what a Sentronic oil pressure unit is.

[Six]

I used crankcase and oil pump to check pressure ( same place oil press safety is hooked to). I dont know what a Sentronic oil pressure unit is.

Oil pressure control for Copeland Compressors. Should be a module on the front of the compressor with a sensor tied into the oil sump.

[socotech]

No module Six.

[jpsmith1cm]

So, it's just a mechanical control. No biggie, we see them every day.

3/4 glass is a shade high, but acceptable. That low oil pressure is bugging me.


I typically see an unloader controlled with a low pressure control, but there are other ways.

I'd grab a full set of system readings, map out a wiring diagram and something will probably jump out at you.

[just_opinion]

...Yes system is dirty.

You may want to pump it down and check the oil filter screen.

Also, there may be trash in the load/unload chamber so that the needle does not seat/seal well or tightly. Thus, the unloading piston chamber is exposed to the suction side and makes it running unload.

https://opi.emersonclimate.com/CPID/...AEB/ae1278.pdf

[Six]

I think Carlyse has the jump on Copeland for better load and unloading of semi hermetic compressors.

[socotech]

Thanks for the help. I'll let you know what I come up with.

[socotech]

Changed the oil three times. Oil was nasty. Replaced suction core and liquid line drier. Checked suction screen. Its now running with 50 psi oil diff. Loading and unloading properly ( low voltage was wired wrong). All seems good except high superheat (35*) and low subcool (5*). 74 suction 317 liquid line. I know probably still undercharged, just wanted to let it run a while and check it after space has cooled.

[supertek65]

35* at the compressor is not that bad!
what is 317 liquid line?
do you have 75# suction or 75* suction line????????

[socotech]

75# suction line
317# liquid line

[Workin4TheMan]

I'm betting on a plugged condenser.

[Six]

Changed the oil three times. Oil was nasty. Replaced suction core and liquid line drier. Checked suction screen. Its now running with 50 psi oil diff. Loading and unloading properly ( low voltage was wired wrong). All seems good except high superheat (35*) and low subcool (5*). 74 suction 317 liquid line. I know probably still undercharged, just wanted to let it run a while and check it after space has cooled.

Two TxVs in that AHU or just one ?

I've got an old York 15 ton that splits off into two circuits at the AHU with two solenoid valves.

Sounds undercharged a bit and maybe you're dealing with a lot of load.

[socotech]

High load (80*). One txv and no solenoid. 100*+ ambient. There is possibly some condenser air recirculation too. It has a solid brick wall on three sides about 20" out.