Copeland Scroll Compressor...Faulty??

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Strahan

Strahan

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Location
Watsontown, PA
Hello everyone, I've recently finished an install of a refrigeration unit which includes a ZR61KCE-TF5 compressor. I'm not an HVAC guy so I need some advice. I've properly sized all motor protection, wires, starter etc.....I had a licensed HVAC guy there upon start up to verify rotation. He gave me the good to go and since then has been working on the unit due to leaks. I received a call tonight that the compressor would not run. Nothing was tripped out and proper voltage was at the compressor but nothing was happening. Turns out this unit has an inherent motor protector which is not accessible. Compressor was hot at the time of my arrival. Not knowing much about this field, I ask there must be a problem with compressor if it tripped the internal protector right? Any advice or direction you can steer me in would be appreciated. Thank You.
 
Googled your model number - appears to be a 480 volt three phase compressor.

I doubt there is any internal overload,

Did you check continuity between input terminals? If there is internal overload check after it has cooled.


Either way sounds like a HVAC technicians problem if you verified proper voltage is present.

However make sure you check line to line voltages and not just line to ground, sometimes they don't break all the lines with their controller, which will result in seeing line to ground on all three lines even though there is no line to line voltage present beyond the controller.
 
Scroll and Recip. Diag.

Scroll and Recip. Diag.

They typically all have internal overloads, and the hot body is a tell tale sign of a charge loss since you have already noted they have been chasing leaks on the system. These are return gas cooled machines and they will do exactly as you have noted, get hot and go off if the charge is short. It is the HVAC man's problem, and if the leaks are not solved quickly it will lead to premature failure of the compressor.
If you walk up to one hot as such and OHM out the compressor terminals they will read open.
A HVACR master Technicians trick for a scroll since they are tall is to take a low pressure pump sprayer and fill it with ice water, and wash the compressor body with cold water until the IOL resets. This process generally can be done quickly and works quite well.
You will then have continuity return to the compressor motor terminals and can see if the unit will then start, but of course should be disabled if the charge is low which is easy to see by the static and running gauge reading once you have your gauges on the system. If 3 phase scrolls are run backwards the result will be the same, and they are notably much louder when reversed.
Single phase scrolls can be forced to start backwards when VERY momentary power dips happen without tripping or having anti-short cycle protection on the load contactor. This is because of the inherent characteristic of the Scroll to backspin when it stops. When this fault happens the result is the exact same, but without any charge issues being apparent.
 
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I concur that the charge is low. Could also possibly be a high side restriction and the compressor is cutting off on high pressure.
 
Sorry it took so long to get back with you all. Currently working the night shift. Thank you all for the responses. Yes it is a 230v 3phase with inherent motor protection. Just wanted some opinions from someone who knows more on the HVAC side of things. Once compressor cooled down I read equal resistance between all 3 phases with no reading to ground. I'm starting to doubt the HVAC tech looking at this because when we initially bumped this compressor over for phase rotation he really didn't seem confident in which way was correct. He actually had me change direction and then put it back to the way I originally had it. As far as I'm concerned I have proper voltage going to the compressor outside of that it's his problem. Thank You all!
 
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