oil pressure problem

[welling service]

I have a 10 ton Copeland discus and a 15 ton copelamatic on a rack system. This is a R22 system. They share a common hot gas line and suction line. The discus maintains a constant oil pressure out put at the pump of 90 pounds. The copelamatic on start up has a oil pressure output of about 85 pounds but it slowly falls and eventually trips my oil pressure control. The discus is a new compressor. The previous discus was doing the same thing. It busted one of the connector rods. The oil pump is new, I have a crank case heater on the comp and there is no foaming in the sight glass. The oil level is 1/2 way up the sight glass. I have installed a new oil separator on the system and it works great. This system is at a Save A Lot store and takes care of medium temp display boxes. It seems like there is an internal oil leak in the compressor causing the oil pressure to fall off. Has anyone encountered this problem before?

[supertek65]

broken connecting rod!!!!!!!!!!!!1

sorry!

but that is most likely your problem!

frank

[Dchappa21]

Check the pressure difference between crankcase and suction valve... How new is this compressor?

[valdelocc]

I would drain the oil check the screen and the pump, it doesnt take long to do it!

[supertek65]

and you can reverse rotation too!!!!!!!!

I would drain the oil check the screen and the pump, it doesnt take long to do it!

[valdelocc]

and you can reverse rotation too!!!!!!!!

Thats right, although there maybe gunk floating around.

whats up with all the chillers avatars? I liked the pink donut better! chillers are the new hvac fashion!I'm a big boy working on big intimidating chillers blah blah blah if I ever get an avatar it would be a window shaker

[supertek65]

LMAO!!!!!!!!!! ROFL!!!!!!!!!!!!!

i like this avatar because it is from a retrofit we did on a 47 year old chiller and the avatar is of the graphics on the adaptaview!
really pretty cool! old retro graphics on an old retro chiller with modern controls!

kind of abstract!

Thats right, although there maybe gunk floating around.

whats up with all the chillers avatars? I liked the pink donut better! chillers are the new hvac fashion!I'm a big boy working on big intimidating chillers blah blah blah if I ever get an avatar it would be a window shaker

[supertek65]

[timebuilder]

Frank, that reminds me.

I have to buy a bench grinder!!!!!!!

[Octopus]

LOL

[jpsmith1cm]

I have a 10 ton Copeland discus and a 15 ton copelamatic on a rack system. This is a R22 system. They share a common hot gas line and suction line. The discus maintains a constant oil pressure out put at the pump of 90 pounds. The copelamatic on start up has a oil pressure output of about 85 pounds but it slowly falls and eventually trips my oil pressure control. The discus is a new compressor. The previous discus was doing the same thing. It busted one of the connector rods. The oil pump is new, I have a crank case heater on the comp and there is no foaming in the sight glass. The oil level is 1/2 way up the sight glass. I have installed a new oil separator on the system and it works great. This system is at a Save A Lot store and takes care of medium temp display boxes. It seems like there is an internal oil leak in the compressor causing the oil pressure to fall off. Has anyone encountered this problem before?

Couple things.

#1. Telling us output pressure is, largely, meaningless. You need to properly measure NET oil pressure, or pump outlet pressure minus crankcase pressure. With a Copeland, that should be 50#.

#2. This 'Copelametic' compressor... Well, a 15HP Copelametic doesn't tell me a whole lot. How about model numbers?


While you're there getting the above information, do me a favor, IF the "copelametic" compressor is a 4D model (one with two heads) pump it down and pull the oil screen.

I would think that, with a broken rod, you'd have a lot of noise and vibration which you haven't described.

[welling service]

Looks like a Trane Centravac Chiller. When these old chillers are running just right with no air in the system they are the quietest chiller ever.

LMAO!!!!!!!!!! ROFL!!!!!!!!!!!!!

i like this avatar because it is from a retrofit we did on a 47 year old chiller and the avatar is of the graphics on the adaptaview!
really pretty cool! old retro graphics on an old retro chiller with modern controls!

kind of abstract!

[welling service]

I know how to check net positive oil pressure. The pump out put pressure is the one that falls. The suction remains constant. Read the post a little closer. I said that the discus has been replaced because it was the one with the busted rod. I have pulled the oil screen and it is clean and I have changed the oil also. It is a 4D model with two heads.

Couple things.

#1. Telling us output pressure is, largely, meaningless. You need to properly measure NET oil pressure, or pump outlet pressure minus crankcase pressure. With a Copeland, that should be 50#.

#2. This 'Copelametic' compressor... Well, a 15HP Copelametic doesn't tell me a whole lot. How about model numbers?


While you're there getting the above information, do me a favor, IF the "copelametic" compressor is a 4D model (one with two heads) pump it down and pull the oil screen.

I would think that, with a broken rod, you'd have a lot of noise and vibration which you haven't described.

[ryan1088]

I know how to check net positive oil pressure. The pump out put pressure is the one that falls. The suction remains constant. Read the post a little closer. I said that the discus has been replaced because it was the one with the busted rod. I have pulled the oil screen and it is clean and I have changed the oil also. It is a 4D model with two heads.

Easy now. Jp was responding to Supertek saying it broke a rod.

[welling service]

Yes jpsmith1cm the discus was making a loud noise and jumping off of its mounts when the rod broke. The bearing was really worn as well as the crankshaft. If i remember right I found the bearing in two pieces after removing the bottom plate for a look see.

[welling service]

ryan1088 if you are implying that I was upset by jp's reply, i was not. I was simply stating that I knew how to measure NPOP and trying to clarify my first post. It looked like maybe I had not given enough detail info.

[supertek65]

Art!
For the right price i will sell you that bench grinder!
It will cost you though!
I just retrofit the controls and starter!!!

[jpsmith1cm]

I know how to check net positive oil pressure. The pump out put pressure is the one that falls. The suction remains constant. Read the post a little closer. I said that the discus has been replaced because it was the one with the busted rod. I have pulled the oil screen and it is clean and I have changed the oil also. It is a 4D model with two heads.

You'll forgive, then, my assumption that you don't know how to measure it because you didn't post it.

As I said, output pressure of the pump is largely meaningless in this scenario.


How fast does the pump pressure drop off?

[jpsmith1cm]

ryan1088 if you are implying that I was upset by jp's reply, i was not. I was simply stating that I knew how to measure NPOP and trying to clarify my first post. It looked like maybe I had not given enough detail info.

[supertek65]

JP

are you insinuating that the cc pressure or suction pressure effects the pressure you would read off the top of the oil pump?

are you insinuating that if the compressor was running on a bench with no refrigerant that his oil pressure would be less than 85 psi?