Trouble w/walk-in freezer Help!

[jreding]

Looking for some advice regarding a walk-in freezer, that is running warn @ 22* F.

Situation is as follows: suction line is iced up from evaporator to accumulator and compressor, there is no CPR on this unit, pressures are 245 (high) and 38 (low) sides. I measured approx. 41* superheat, by using gauges and thermocouple.

This unit is a 2 H.P. copeland compressor, R-502 one of the guys decided it was the TXV and tinkered with the setting, then finally replaced the TXV.

The unit has been defrosted many times and the defrost timer is functional, also the unit runs continously, unless the defrost timer is telling it to shutdown at its proper time.

Any Ideas?

Filter/drier? pressure control? compressor?

Thanks so much!

John

[rasheed2323]

TXV may requered fine tuning

[wambat]

CK for low amps and the difference in temperature between the condenser temperature and the ambient air the “Condensing Split,” and it should run from 25-30˚ on standard-efficiency condensers under normal heat loads you may have bad valves

[tony--1]

Do a pump test on the comp. see if it can pull and hold a vac. txv may be ok could be the comp ?

[paul_h]

Well before you play with it, after reading some horror stories here and elsewhere, have you considered the fact that it's not built right?
Maybe get some history on the install and equipment, do a heat load calc and check the evap, compressor and the rest of the gear is up to the job.

[Gary]

I hate it when people tell me pressures instead of temperatures. They are forcing me to dig out my P/T chart. I don't care what the pressures are. I want to know what the corresponding temperatures are.

[jreding]

Thanks for the responses I will look more into it, If i remember correctly its about 8* low and 105* high.

its located, (of course in the most god awful space) on top of the freezer, ( 2' of clearance in top).

They did put a fresh air intake into the area, via a st of louvers through the exterior wall.

Thanks again.

John

[Gary]

Thanks for the responses I will look more into it, If i remember correctly its about 8* low and 105* high.

its located, (of course in the most god awful space) on top of the freezer, ( 2' of clearance in top).

They did put a fresh air intake into the area, via a st of louvers through the exterior wall.

Thanks again.

John

If the SST is 8F and the superheat is 41F, then the suction line must be 49F. Yet you are saying that the suction line is frosted. How is that possible?

[Gary]

For a proper evaluation, we need the following information:

Low side:

Evap air in temp
Evap air out temp
Saturated suction temp (SST) converted from pressure
Suction line temp at evap outlet

High side:

Cond air in temp
Cond air out temp
Saturated condensing temp (SCT) converted from pressure
Liquid line temp at receiver outlet

[shawn626]

does the compressor pump down into a vacuum if you front seat the suction service valve?. aslo is there a low pressure control used as a safety that ma be set above the required sst?.