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View Full Version : unit wont go below 48f, yes set temp is 35f



norsk
02-02-2012, 06:02 PM
404a system, unit will not go below 48f box temp.
Compressor is very cold, very low low side pressure, very low high side pressure, suction line cool
filter drier slightly warm, liquid line slightly warm, condenser discharge line slightly warm, discharge air
is slightly warmer than ambient. Total superheat is high but box temp was 48f.
adjusted the TEV from 1 turn in 1 turn increments to 4 turns open, at every setting the box still would
not pull below 48f.
Is this a bad TEV or bad compressor???

AlexG
02-02-2012, 06:10 PM
Discharge line slightly warm? Strange. It must be hot. What is suction superheat?

chemi-cool
02-02-2012, 06:43 PM
Check your compressor valves.
What is the currant draw compare to compressor label?
Any head pressure control?

pirestani
02-02-2012, 06:51 PM
If your unit is integrated AC package,it may some cold(conditioned) air leakage from cooling chamber to condenser.
otherwise you,d better to look for something wrong in compressor.

Emmett
02-02-2012, 07:32 PM
low charge?

monkey spanners
02-02-2012, 07:37 PM
If the compressor wasn't pumping well the suction pressure would be higher than normal not lower.

Suspect a shortage of refrigerant, a restriction or a failed txv.

ammoniabreath
02-02-2012, 07:39 PM
sounds like lack of load is evap fan running , is evap iced up/ or dirty causing lack of air flow, have you got a full charge of gas, what is suction superheat, what compressor is it, has it got loaded cylinders. Give me as much info as you can and i will help you resolve issue.

norsk
02-02-2012, 07:44 PM
Thanks to all who replied
It was a bad TEV, replaced it, now the unit pulled down from 80f to 35f in about 10 minutes
guess the TEV was in a stuck open position

mbc
03-02-2012, 03:43 PM
could you give us these information to give you right suggest .

outside temp.( in condenser position )
room temp.
suction pressure
discharge pressure.
is side glass is full.
compressor size with current (A) with voltage on that.
does compressor has a sound or vibration on working time.
when compressor goes off , does suction and discharge pressure move to be equal fast or it takes time.

Sandro Baptista
03-02-2012, 05:21 PM
If the compressor wasn't pumping well the suction pressure would be higher than normal not lower.

Suspect a shortage of refrigerant, a restriction or a failed txv.

I also agree with you.

AlexG
03-02-2012, 07:26 PM
Norsk, good one. That's why we asked about suction superheat.

Magoo
03-02-2012, 09:12 PM
Hi Norsk, thanks for feed back, that your problem is sorted