R22 coolroom high suction norm discharge

[Andrew K69]

i had a scroll compressor which had a leak on the discharge port. the comp was only 6 months old. the system lost basically all of its charge. didnt have a vac pump so i just charged it back up. it ran fairly well for the first ten minutes then as i continued to charge the suction pressure just kept getting higher and higher but the discharge stayed the same. in the end suction was 700 kpa and discharge was 1150 kpa. could this be because i didnt vac it out?

[nike123]

it ran fairly well for the first ten minutes then as i continued to charge the suction pressure just kept getting higher and higher but the discharge stayed the same.

If it run fairly well, why did you continued to charge.
What that "fairly well" mean in numbers on gauges and thermometers.
For correct diagnosis we need:

Evap air/water in temp
Evap air/water out temp
Low side pressure or saturation temp
Suction line temp at evap outlet
Suction line temp at compressor inlet

Cond air/water in temp
Cond air/water out temp
High side pressure or saturation temp
Liquid line temp at receiver or condenser outlet
Liquid line temp at TXV inlet
The more information provided the more accurate the diagnosis.


At first ball, I would say bad compresor valves.

[sedgy]

hi andrew, dont you have fridge tec ,s down under?

[paul_h]

Andrew are you trolling?
:rolleyes:

[Andrew K69]

well i dont think its bad comp valves as it is a pretty new comp, but why would it have such a high suction pressure and a normal discharge? im stumped!!

[nando]

the valves of the valve plate leaks from high pressure to low pressure

[monkey spanners]

Compressor is faulty (assuning its copeland...), thermal doodad in ther head has opened and not shut again hence its effectively not pumping.
Can you shut the suction valve and see how well it pumps and then shut it off and see how quickly it equalizes and let us know?

Also whats with the no vacuuming? This isn't helping either.

It doesn't matter how old equipment is, even at 6 months it will fail if run out of is design parameters.

[FEISTY]

The recharge without a vacuum tells us all something about the " tech " level of knowledge. Just a thought...you know...if you switch the hoses on the manifold and read suction pressure on the high side and discharge on the suction gauge the " crazy " readings may happen. Hell...I've done it in a dark basement late at night and tired. Again...just a thought.

[Tankerbox]

you have bad valves!!!!!1

[james770]

did do weigh the refrigerant cause if it is overcharge you will get wrong readings

[razor007]

scroll compressors generally dont have valves as they are an inter-meshing scroll mechinisim that compresses the refrigerant the discharge pressure relief valve inside the compressor may be faulty or the unloader valve inside the scroll may be faulty also. if you dont have a vac pump sounds like you shouldn't be playing around with it lol

[Roadrunning123]

Can be non condensable in the system or discharge valves are shot.
I would say if it's a scroll and you charged it up from slight positive pressure or you purged it, it will be the compressor valves.
I'll tell you why.
Scroll compressors are a very good compressor but ! They stuff up really easy.
One thing you have to remember about scrolls is that you can't charge them from scratch with vapor as you would with normal tin cans ( hermetics) the only way to charge a scroll is after it has been dehydrated ( vact out) is to push 3/4 of the gas charge into the discharge side of the system first before start up , the reason for this is that if you vapor charge from the low Side, the compressor can pump all it's oil straight out of the sump leaving it dry and this causes va
Ve and bearing damage almost immediately after the gas up.
Once you have put 3/4 of the charge into the discharge , the compressor now has enough gas to pump leaving the oil in the sump.
The rest of the charge can now be put through the suction until operating pressures are reached.
This technical advise is direct from copeland compressors who also recommend not to dehydrate lower than 500 microns because it plays havic on the windings.

Cheers
P,s make sure you put a new dryer on as well