Scroll compressors Smashing up

[Jasper]

We have a site with multiple downflow CRAC units that keep smashing compressor scrolls!
The compressors are tandem sets of Sanyo 30kw units
We think this is due to liquid migration into the compressor crank case during the off cycle
Whilst observing operation of the systems we have noticed that the head of the compressor that is not running is getting hot whilst the sump is relatively cool to the point of moisture occuring on the outside!
My question is "do you think non return valves should be fitted on the discharge pipe of each compressor to stop discharge gas being forced past the scroll of the off cycle compressor and should we also fit crank case heaters ?

[Grizzly]

A similar problem was solved by fitting non return valves in the pipework on early Danfoss scroll setup's.
Also fitting crankcase heaters and insulated jackets had a part to play!

Issues completely resolved since.

Grizzly.

[chemi-cool]

Grizzly was faster but that exactly my advice. Make sure the crankcase heaters are energized all the time.
NRV is a must on all tandems, triples and multiple compressors set up.