Scroll Compressor

[dwallan]

I don't work with that many scroll condensing units but recently I took on a site with such a unit with a few problems.
I seem to recall a discussion with a forgotten party concerning the fact that scroll compressors should not be used on a pump-down set-up.
Can anyone shed some light on this.

David

[terrygoodrich]

Copeland has developed scroll units for commercial refrigeration that may be used with liquid line solenoid valves for pumpdown systems. An improved discharge check valve is incorporated into the compressor. A small amount of high pressure gas blows backward through the scrolls on shutdown, causing reverse rotation briefly. Air conditioning compressors may not be suitable, however, for pumpdown operation. Check with the manufacturer on you particular applications.