TXV Faults

[cooper3305]

Hi fine gents.

Here's the story. I have a 130kw heat pump water/water x2 circuits per heat pump. These heat pump use Sporlan BBIZE-15-GA TXV (TEV'S depending on which way you dress) and there are 2 per circuit inline (7/8 TEE then to TXV then to drier then TEE'd to 7/8). Having just changed the compressor I checked the bulb line and found the charge was gone. The compressor had burnt out. The question I have is this....If one of the TXV's on the same circuit (sharing common pipework) fails what would be the knock on effect? I am suspecting this is the reason the compressor failed and what happens is that by losing a TXV it is more or less a restriction. Problem is that the system does not act like its a restriction except for lower Delta T across the load heat exchanger.

Any ideas fine gents?

[chemi-cool]

When a TXV looses the charge, it closes almost completely. Compressor was not getting enough cooling and most probably there is no low side pressure control so the result is a burnt compressor.

[monkey spanners]

To add to what Chemi said, if the system runs long enough with one failed txv the lubrican gets trapped in the evaporator with the failed txv due to there not being enough flow to bring it back to the compressor.

[savoc]

you would lose your superheat and comp will heat up possible burn out or seize. do all the safety control work? what went wrong with the compressor?