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ref tech101
03-10-2010, 08:24 PM
Hi,wondering if someone could help me..what is the result on a compressors oil,windings and mechanical wear with the oil seperator leaking tru discharge vapour.not liquid....

Brian_UK
03-10-2010, 08:28 PM
Excessive wear due to high oil temperature as well dilution of the oil.

Expect compressor to die shortly.

ref tech101
03-10-2010, 08:33 PM
If you dont get it to close do you replace it?

Brian_UK
03-10-2010, 08:59 PM
Oil separator needs cleaning out, probably debris under the float valve.

Magoo
03-10-2010, 11:44 PM
You can get wire drawing in the needle valve of the float assembly in separator that allows hot vapour to leak back to compressor. Time to replace the oil separator

ref tech101
04-10-2010, 05:35 PM
Hi one more Q..or 2 lol..Is their a way of cleaning a sealed oil sep when this happens,or do you just replace it?This hot vapour that leaks back,their is the risk of the compressor overheating and burning windings if the thermistor is not working..if its not suction cooled?Does a valve reed leaking have the same effect on the compressors temperature?

sterl
05-10-2010, 02:31 PM
1) Gas coming back from Oil Separator would carry all separated oil with it...So its not quite the same as recirculation caused by leaking compressor valves. In a multicylinder, leak on one valve causes one cylinder to be hotter than another.

2) Operating envelope of compressor is going to be effected in either case. With multicylinder leaking suction valve will effect only marginally. Leaking discharge valve will cause much the same effect as gas returned from oil separator. In all the cases: machine won't make lowest possible suction pressure and won't make full capacity at any suction pressure. For leaking DOS: Machine current should remain virtually the same but crankcase temperature higher. For leaking discharge valve: Crankcase temperature should not be effected but cylinder temperature will be. For leaking suction valve: Crankcase temperature will be higher but may not be noticeable.

3) All three are going to effect flow over motor. If the compressor is operating near its minimum suction pressure the effect will be large. If the compressor suction is nearer the high suction end of its operating envelope effect will be less noticeable.

A complete operating envelope for the specific compressor as well as the operating pressures will permit you to quantify the mass flow effects; the exact thermal effect on the motor is a little trickier but the net energy change if reasonable easy to derive.

ref tech101
05-10-2010, 05:42 PM
Thanx for ur post...it makes sence when you say when it gets to lower presures as the coldroom stars getting on temp.
Less suction cooling and higher evap temp in both cases.I geuse in low temp systems you lose even more capacity.