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Check the lineset length and configuration. this seems like a symptom of the compressor losing the top bearing due to poor oil return. could be loooong lineset, or imporplery sized risers.

Y'all seem to have covered most everything. Do you know if this compressor runs pretty cool to the touch? Does it have an internal relief valve? Check to see if it is dumping refrigerant into the dome of the compressor. It will be very hot if it is. It sounds like the compressor has seen better days.

Completely agree with AlcoMech. Change compressor, install suction dryer. When you get it up and running, you must find what caused the comp failure, or you will be doing it again...just a matter of time.
Like I tell my guys constantly....Keep asking yourself.."why"!.. ;compressor failed?,why?... inadequate oil return?, why?..inadequate refrigerant flow?, why?...restricted refrigerant flow trapping oil?,why? etc.
We get paid to fix the problem, not just a symptom of the problem.

Originally Posted by B1978

It could be oil return. If you dont draw the oil back your amps will rise as it runs. It may start normal then rise up. I would be thinking that route.
I have heard some will mix in some POE to help draw mineral back?

B1978 I think that you are on to something here. A scroll compressors life depends on oil and is not forgiving if it lack oil return. The symptoms here are very clear that that scrolls are locking up. A very common cause happens when that scrolls lack oil and grind on themselves. Once this happens its over and the problem only gets worse when you have fine metal fragments floating around. If this is the problem then the only solution is to R/R the compressor.

The interesting part however is preventing the next failure, Many recommend the installation of an over sized Suction dryer, due to the fact that a standard 16 Cubic dryer will not pick up this fine particles in the system.

Air flow will also need to be checked, and if low this will cause oil migration to the evap coil.

As for mixing oil this is not recommended as 41O is a blend and requires the use of POE oil which has an Azeotropic behavior. If Mineral oil is mixed two separate liquids would form and oil loss will occur.

How much different is discharge pressure from liquid line pressure?

P.s. changed the compressor and all is well

I would verify you are not running backwards. Copeland has had a rash of compressors wired backwards from their labeling on the electrical housing. I recently found out the hard way.

Ok, when you say discharge pressure, does that really mean liquid pressure?

Is there a internal filter drier in that cond unit?

If you are really measuring discharge pressure I think your going to need a new compressor.

I had a 5 ton Goodman with roughly the same issue the other day. It turned out to be a clogged filter drier in the bottom of the condenser, had to go all "Heels to Jesus" to swap it out. Not fun.

It could be oil return. If you dont draw the oil back your amps will rise as it runs. It may start normal then rise up. I would be thinking that route.
I have heard some will mix in some POE to help draw mineral back?

Originally Posted by jimj

My guess would be the bearing are going bye bye. 30 amps on a 5 ton 3 phase compressor? Not long for this world!

What he said. I had one start at normal amps then climb as it ran until it tripped. Boss thought I was crazy changing compressor but had no other ideas, then was happy when it fixed the issue.

Check your volts when running? Bad contacor breaker disconnect? Tighten all connections check voltage drops across them and temps..

Its a matter of time before it fails

If its pulling high amps then condemn the compressor

Thats what happens when you run twice the correct charge with a dirty evap!

RLA 20A
LRA 120A

My guess would be the bearing are going bye bye. 30 amps on a 5 ton 3 phase compressor? Not long for this world!

What is the LRA and what is the compressor rated at? 30 plus amps sounds high in a 5 ton system.

What else could this be? I was thinking shorted windings

Originally Posted by wdshea

The olp trips pretty quick, it never pulls less than 30 amps, so it only runs about 5 minutes, if that. I thought that maybe a previous tech may have the motor running backwards, so i switched some leads. AmP draw went to 12A but the compressor sounded like hell, so i'm certain it was running the right way.

A grounded winding will typically pop the breaker/overload instantly, not over a couple of minutes.

The olp trips pretty quick, it never pulls less than 30 amps, so it only runs about 5 minutes, if that. I thought that maybe a previous tech may have the motor running backwards, so i switched some leads. AmP draw went to 12A but the compressor sounded like hell, so i'm certain it was running the right way.