Cold compressor!!

[N.Lewis]

Hi guy's..just replaced comp on an isovel DX system, used for cooling a computer room, everything went o.k, comp running, readings on guages suc-75psi diss-250psi, suc line nice and cool diss hot, no blockage in T.E.V or drier, temp of unit great, but whole of comp is v.cold to touch, has been running for aprox three hours, would expect comp to be warm all over by now....Am i worrying about nothing or is there a hidden prob i'm not seeing!!!

Thanks for any reply's..

[Sturt]

Can you tell us the suction supheat?

I would guess flooding back.

Sturt.

[albionharley]

Got to agree with Sturt - sounds like liquid flooding back. Probably why the compressor failed in the first place.

[N.Lewis]

Thanks for replies guy's, havent checked super heat today, will check and rectify, will keep you posted if interested.

[albionharley]

Hi - yes would be interested how you get on . What compressor is it and does it have service valves ?

[powell]

but whole of comp is v.cold to touch, has been running for aprox three hours, would expect comp to be warm all over by now...Am i worrying about nothing or is there a hidden prob i'm not seeing!!!

N.Lewis,

The first compressor failed for a reason. If you don't find the cause you will loose the new compressor. Seems like you're getting a good sign of the first compressors reason for failure.

As others have stated, check the superheat.

[N.Lewis]

Hi guy's, just to keep you updated, compressor make is compact, and yes it does have service valves, checked superheat, got a reading of 18.5degF, after some adjusting of t.e.v this morning have got that doen to 11degF, comp is now running a little warmer, by the way unit is R22, set point for cooling is 12degC which it is maintaining...Any more info req please let me know...cheers.

[paul_h]

Airflow on the indoor, air on/off? ducting and filter condition?
Fan speed/amps in spec?
Coil and fan blade dust buildup?

[Brian_UK]

Hi guy's, just to keep you updated, compressor make is compact, and yes it does have service valves, checked superheat, got a reading of 18.5degF, after some adjusting of t.e.v this morning have got that doen to 11degF, comp is now running a little warmer, by the way unit is R22, set point for cooling is 12degC which it is maintaining...Any more info req please let me know...cheers.

Your technique of mixing the temperature standards had me going for a while there.

Are you saying that by reducing the superheat the compressor has warmed up ?

[albionharley]

Hi- i know its late but- not sure why reducing the superheat would cause the comp to warm up. Surely if anything it will increase the chance of liquid flooding back ? As i say it is late so perhaps it's me !

[Brian_UK]

Well that's two of us AH.

[Husky250]

What is the outdoor DB temperature and Indoor WB temperature. The 75 psi suction and 250 discharge is really close to design conditions. Usually design conditions are 95 degree outdoor and 80 degrees indoor. If you are cooler than design conditions and still holding same suction and discharge psi you are way over charged. Hope this helps.

Husky

Hi guy's, just to keep you updated, compressor make is compact, and yes it does have service valves, checked superheat, got a reading of 18.5degF, after some adjusting of t.e.v this morning have got that doen to 11degF, comp is now running a little warmer, by the way unit is R22, set point for cooling is 12degC which it is maintaining...Any more info req please let me know...cheers.

[nike123]

Hi guy's, just to keep you updated, compressor make is compact, and yes it does have service valves, checked superheat, got a reading of 18.5degF, after some adjusting of t.e.v this morning have got that doen to 11degF, comp is now running a little warmer, by the way unit is R22, set point for cooling is 12degC which it is maintaining...Any more info req please let me know...cheers.

Now, check your subcooling and / liquid sight glass for proper refrigerant charge when conditions are near designed, as well as when conditions are low ambient/low load and high ambient/high load.
Low ambient and low load check is for ensuring that liquid is not present at compressor inlet in this extreme condition.
High ambient and high load is for check that you have enough refrigerant for ensuring that TEV has always liquid refrigerant at his inlet at this extreme condition.

[sudarmanto]

Low ambient and low load check is for ensuring that liquid is not present at compressor inlet in this extreme condition.
High ambient and high load is for check that you have enough refrigerant for ensuring that TEV has always liquid refrigerant at his inlet at this extreme condition.[/quote]

if in the low ambient check he find liquid present at comp inlet then what should he do next..

[sudarmanto]

this morning have got that doen to 11degF, comp is now running a little warmer, by the way unit is R22, set point for cooling is 12degC which it is maintaining...Any more info req please let me know...cheers.[/quote]

by the way, as far as i know, for computer cooling, the setpoint maintained 18 to 22degC and RH 45 to 50%..its related with the computer reliability..(probably not related with your compressor topic ya. sorry..)

[nike123]

if in the low ambient check he find liquid present at comp inlet then what should he do next..

Then he need to take measures to rectify that !
It could be instalation of suction line heat exchanger to boil that liquid or setting higher static superheat, or installing some suction accumulator.

[N.Lewis]

Hi, just to confirm brian and AH, i was not suggesting adjustment of superheat is the cause for comp heating up, when i posted subject i was just looking for help on the original prob, superheat adjustment was suggested by some of the guy's so that is what i looked at, i thought 18.5degF was rather high as we are always told 4-6 or around 10deg is what we should be looking for (refer to many back posts), so after getting SH down to aprox 11degF comp did warm up?? Anyway system is running o.k so all good.
Again thanks for all replies..