Low head, normal suction, HIGH amps

[wdshea]

5 ton scroll compressor in a split system.

Suction ~40psig
Discharge ~210psig
Amps 30+A
Superheat ~17

It is a 3 phase compressor, pulls 30 amps from the get go and will go all the way to 40 amps (and shut off)

The winding(s) resistance is about .5 ohms on all of them. It also doesnt sound great when it is running. I recovered 20 pounds of refrigerant from this system, recharged with around 7.5 pounds... After cleaning the ridiculously dirty evaporator.

Just looking for affirmation, thank you for your input.

[beenthere]

7.5 pounds sounds low on a 5 ton split system.

[jpsmith1cm]

5 ton scroll compressor in a split system.

Suction ~40psig
Discharge ~210psig
Amps 30+A
Superheat ~17

It is a 3 phase compressor, pulls 30 amps from the get go and will go all the way to 40 amps (and shut off)

The winding(s) resistance is about .5 ohms on all of them. It also doesnt sound great when it is running. I recovered 20 pounds of refrigerant from this system, recharged with around 7.5 pounds... After cleaning the ridiculously dirty evaporator.

Just looking for affirmation, thank you for your input.

Did you measure amps on all 3 legs?

[stinkypinky]

I'm guessing R-22. If so looks like low suction, normal head. more info would help. I like to megaohm the compressor to ensure the windings are good.

[maxster]

split unit what was the ambient around the condenser 210PSI air cooled is low for R-22.how is the condenser on being clean...flush it inside out.... is this a commercial site strip mall or residence?

[wdshea]

Im sorry, i was thinking of my suction saturation when i said 40, pressure was around 69psig on the suction. Yes i checked all three legs. I cleaned the condenser twice. This is commercial.

Megaohm the windings to ground?

[Six]

You can use a megger if you have one. Isolate the leads from the compressor and megg from the compressor terminals to ground.

[jpsmith1cm]

typically, a short to ground is not going to cause high running amperage.

That would be more likely to cause high instantaneous amperage and result in a breaker trip.

I would leave the megger in the truck here.

I'd look for a performance curve on that pump and see what the manufacturer says that it SHOULD draw under those conditions.

I suspect that you'll be replacing a compressor, soon, though.

[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.

[jpsmith1cm]

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.

[wdshea]

What else could this be? I was thinking shorted windings

[Huntinwalkerstyle]

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

[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!