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mciver_53
08-07-2010, 12:40 PM
Hello,

New to re site,

I was replacing a Carrier 06-E compressor and found that the crankcase heater, (plug into sump type) failed overnight. I checked it that afternoon all ok and found it not working and open cct the next morning. I had the system with oil to the base of the sightglass, and had left the system under vacuum overnight ready to charge the next day. It was a very old heater id say 15 years plus.

My boss has now advised me to leave crankcase heaters off while evacuating a system? Any truth to this? I would have thought its best to leave them on.

Cheers, James

coolhibby1875
08-07-2010, 02:46 PM
i wouldn't have thought it would make a blind bit of a difference to be honhest!!

taz24
08-07-2010, 04:29 PM
Hello,

New to re site,

I was replacing a Carrier 06-E compressor and found that the crankcase heater, (plug into sump type) failed overnight. I checked it that afternoon all ok and found it not working and open cct the next morning. I had the system with oil to the base of the sightglass, and had left the system under vacuum overnight ready to charge the next day. It was a very old heater id say 15 years plus.

My boss has now advised me to leave crankcase heaters off while evacuating a system? Any truth to this? I would have thought its best to leave them on.

Cheers, James


I can't see the vac causing the problem.

If the oil was low that could cause it to fail, but you
said it had enough oil inside.

Things fail and it is more than likely to be pure coinsidence.

taz

.

goshen
08-07-2010, 06:47 PM
Hello,

New to re site,

I was replacing a Carrier 06-E compressor and found that the crankcase heater, (plug into sump type) failed overnight. I checked it that afternoon all ok and found it not working and open cct the next morning. I had the system with oil to the base of the sightglass, and had left the system under vacuum overnight ready to charge the next day. It was a very old heater id say 15 years plus.

My boss has now advised me to leave crankcase heaters off while evacuating a system? Any truth to this? I would have thought its best to leave them on.

Cheers, James
Hi :
i cant see any connection ,a simple murphys law,in action,heating the oil is helpfull in removing moisture and refrigerant :)

NoNickName
09-07-2010, 07:15 AM
Come on. Eveybody knows that the vapour pressure of refrigerant is a function of temperature. The higher the oil temperature, the better the vacuum.
It's written in each and every manual of compressors: keep the heaters on while evacuating.
RTFM!

mciver_53
11-07-2010, 11:02 AM
Thanks guys, with some bosses, even when your right, your wrong. Will keep heaters on when pulling vacs anyways, thanks James..