Trane compressor burnt terminals
We have two Tandem 15 ton Trane scroll compressors on a Trane chiller
Up until now they have been working great for about 8 years with a head pressure no higher than 190 Pounds
Yesterday one of the compressor blew out its electrical leads
We lost all the refrigerant
I am going to replace both of them
Some of us attribute this to a normal occurance
Am I right in going with the idea that this was due to
acid in the refer oil ?
i do not believe that acid would cause a terminal blow out. i believe that you probably have acid in the system now. i do not think that i would just automatically change out the other compressor as long as the windings are good electrically (meg 'em). you can buy a lot of oil changes for the cost of a new compressor. however, if you are not absolutely sure, you are probably better off with a new compressor, just to be safe.
copeland has stated that if you have a compressor in a near (you define the term "near") perfect vacuum, and apply voltage across the terminals, you get the "corona effect" where the current will jump across the vacuum from one terminal to the other terminal (internally) and the end result is a terminal blow out. supposedly, the recip compressors can't get there (although i think that i came across one that did) but the scrolls can get there. page 5 of the application bulletin that i uploaded. i think that it is in most of their scroll lit.
you may need to check that your liquid line solenoid valve still operates and that the 7 psig low pressure switch is still working well.
If not being done already, this may be a good time to stress the importance of preventative maint. including annual megger testing, oil analysis, and tighten all electrical connections. Sometimes the terminals at the compressor can loosen causing heat, or an insulation breakdown causing a terminal to blow out. I could see how acid could be a factor in a failure, but would have been caught if the oil was tested.