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Ed Fitz
28-04-2010, 04:59 PM
Hello,
can any one tell me how many bench tests can be done on semi hermetic compressors without
using *****, from 3hp up to 60 hp
thanks !!
taz24
28-04-2010, 05:01 PM
Hello,
can any one tell me how many bench tests can be done on semi hermetic compressors without
using *****, from 3hp up to 60 hp
thanks !!


They run them for a short period of time on OFN (nitrogen).

They do not run them for too long because they overheat but they have a big rig that lets them
connect up.

taz

.
NoNickName
28-04-2010, 05:56 PM
Yes, manufacturer of compressors test them with OFN shortly.
chillin out
29-04-2010, 08:33 PM
Are you sure?

I don't think I would run a comp with nitrogen in it.
A small comp will not be able to compress it.

Chillin:):)
monkey spanners
29-04-2010, 08:43 PM
Are you sure?

I don't think I would run a comp with nitrogen in it.
A small comp will not be able to compress it.

Chillin:):)

They can compress it, its squishy cos its a gas, the problem comes in a fridge system because they can't condence it hence a stupid high discharge pressure in no time.
On a specially designed test rig it would be ok, it would just measure flow, pressure and run current etc and compare to a new comp specs.

Jon :)
NoNickName
30-04-2010, 07:29 AM
A compressor compresses whatever gas it sucks. Why shoudn't it be able to compress it?
Surely, the max ratio depends on the compressor, though...

The way it works is exactly as monkey spanners explained. It's not tested on a condensing unit.
sedgy
03-05-2010, 07:31 PM
hi all , AIREDALE the yorkshire based a-c manufatorer test runs there units on ofn
D.D.KORANNE
05-05-2010, 11:11 AM
The important test is the leak back test which sets a limit for the discharge reed valves to suction valve reed . Do not run semi-hermetic comp on N2 . Do a free run test . The compressor builds up an air pressure of say 120 psig in a receiver tanks , switch off the compressor & measure leak back flow .
sedgy
05-05-2010, 03:00 PM
MR dd KORANNE, YOU ARE RIGHT do not use N2 on any fridge compressor, use OFN, THAT IS OXYGEN FREE NITROGEN
NoNickName
07-05-2010, 06:38 AM
The important test is the leak back test which sets a limit for the discharge reed valves to suction valve reed . Do not run semi-hermetic comp on N2 . Do a free run test . The compressor builds up an air pressure of say 120 psig in a receiver tanks , switch off the compressor & measure leak back flow .

No. Don't follow this advice. Semi recips for refrigeration and air conditioner shall never be pumping air.