"JR North" wrote in message
...
Can't do it. The compressor is cooled and lubed by the refrigerant and
oil charge. It will overheat quickly without it, and the thermal
shutdown activates.
JR
Dweller in the cellar
JR, I wonder if we are thinking of the same sorts of compressors?
There seems to be dozens of examples of where people are using them for
vacuum pumps and low volume compressed air sources. I cant remember where I
found the info but supposedly the hermitically sealed ones are the best to
use.
I've run the compressor for about 1/2 an hour. In bright light I can almost
see some mist coming out of the high pressure side. I wrapped some paper
towel around it for a while thinking I'd trap some oil but got nothing -
residual refrigerant perhaps??
I guess the other point is longevity - to me 50 or 100 hours continuous
operation before failure would be acceptable considering my intermittent
use.
On the other hand I know bugger all about fridge compressors otherwise I
wouldn't be asking here!
On Sun, 25 Sep 2011 19:31:44 +0800, "Dennis"
wrote:
I picked up a small fridge compressor with the idea of playing around
using
it for a vacuum pick up tool for small electronics parts, but it behaves
strangely.
On initial power up it runs fine, very quietly.
It quickly/easily pulls down to 20kpa (-80kPa).
However if I disconnect the power and reconnect there is a quiet hum like
the motor is stalled (motor is not running & there is no airflow).
If I disconnect again then wait a minute or two before reconnecting it
powers on fine and will run fine - I've let it run for 5 minutes
continuously with no problems.
As part of the terminals to the motor there appears to be a thermal
overload
switch, it gets warm but not hot (my guess ~30 Celius)
Heres a link to the data sheet:
http://www.transtech-co.jp/electroni...ompressor7.pdf
I vaguely recall something about fridges having protection against rapid
cycling of the power for some reason - but that could be rubbish. If there
is some sort of anti-short cycle timer it must be inside the compressor
housing itself.
Any ideas?
Thanks.
HOME PAGE:
http://www.seanet.com/~jasonrnorth
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