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Did the wrong rotation kill the scroll compressors??

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11bgrunt

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Discussion starter · #1 ·
New to the forum and am a electric utility employee.
This building has six 7.5 Ton Gas Heating/Electric Cooling Single Package Units. Three are 2007 and three are nine months old. All was well until the electric breaker panel serving these units was changed out. After power was restored, some of the units were found turning wrong rotation . Then three of the compressors failed. Two new, one old.
We can't guarantee how long they ran in this state but long enough for the owner to know something was wrong.
Can this kill a scroll compressor?
HVAC and electrical contractors accepted no responsibility. Their response is "the voltage is too high". The power supply is 480/277 averaging 490VAC phase to phase.
The utility set voltage recorders and found no issues.
 

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Discussion starter · #4 ·
I am there to troubleshoot after the compressor failures. We had no involvement in the hvac or electric work done at this site.
It is logical that wrong rotation is common to the failures.
Do any electricians or hvac tech use a rotation meter?
 
#12 · (Edited)
VTP99 said:
This is going to fall back on the electrician provide no utilities were disconnected.
Click to expand...
X2. Sparky should know better......operative word should...because I have seen that mistake made before. It is the electricians responsibility to ensure that all motors are operating correctly after major work like that. They should have sub contracted an HVAC contractor to inspect all the HVAC equipment if they didn't know how to check it.


As others have said, reverse rotation will kill a scroll compressor.

Sent from my SM-S906W using Tapatalk
 
#17 ·
If the sparky is really nice to the a/c guy he might be able to run the newer ones through warranty.
Hope like hell the manufacturer doesn't do a tear down 😳
 
#19 ·
Electrician should have used a phase sequence meter.
Scroll would be rated for 460vt, +-10%,~505 max.
Copeland scrolls would typically cycle on high discharge temp motor protection. Other brands may not have the same protection or tolerance.
Lubrication would be limited on any due to the supply feed method.
PVM’s are cheap protection (~$50) and should be used on all 3 phase compressors.
 
#20 ·
That electrician was me.....many years ago.

We changed out the service equipment in an office building over a weekend.

All was well until Monday, building manager called HVAC because AC not working well.

Compressors and condenser fans were running backwards.

Compressors were all recip, this was long before Scrolls were invented.

HVAC svc call fixed it......cheap lesson learned.
 
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