joe magee
05-02-2011, 07:32 PM
I worked on a thirty ton two circuit downflow air cooled Data Aire unit. The one circuit with a scroll compressor was tripping on the hpc. There was no rhyme or reason as to why or when it would trip. Cold outside,warm out etc. The discharge pipe came out three feet horizontal and fifty up the wall to the aircooled condenser. There was traps on the liquid line so liquid would not migrate back to the compressor, the crankcase heater was working. After checking all the common problems I decided to install a checkvalve on the outlet of the discharge line. That worked.
I know scrolls have checkvalves in the compressors and usually when they go bad you can here the scroll spin backwards when the compressor shuts down but not in this case. This was a new install. So my question is why did this work?
We have thirty other units piped the same way and no problems. Is it possible a check valve was never installed on this compressor and at start up it would trip. It never did it while I was there. The other circuit never tripped:)
I know scrolls have checkvalves in the compressors and usually when they go bad you can here the scroll spin backwards when the compressor shuts down but not in this case. This was a new install. So my question is why did this work?
We have thirty other units piped the same way and no problems. Is it possible a check valve was never installed on this compressor and at start up it would trip. It never did it while I was there. The other circuit never tripped:)