walkin freezer help

[joeyjoseph123]

Hi guys Would you be able to guid me on a few things i been in ac four a few years i just started with the working on the freezer im having problems with a 404a -10f box its stops at 20f i have clean cond and evap good air flow my suc was 32g i was getting 19 deg super back to compressor and the coming from evap i had 4deg superheat i did notice that i check the pull down on the compressor and it would only go to 0 but held it would not go any lower is that normal for a copeland semi hermetic i thought that it should be able to pull a vacuum with no problem could this be just compressor problem the amps were normal and btw what is the most common problems with the freezer that they seam to be i seen this a few times were the boxes 20f no colder and it seams that every things is good but it cant be give me a clue LOL thanks

[joe magee]

I'm not sure what your suction is but for a -10 it would be aprox14 lbs for 404a. Check your txv screen. If there was a problem with your compressor it would not pull down to the proper suction for your temp.As far as checking the compressor It should pull in a vacuum and hold granted your ssv holds. Make sure the proper pwr head is on the valve, sz in this case. There could be other issues but check those first.

[nike123]

Hi guys Would you be able to guid me on a few things

Yes, but you should start writing in manner that we old timers understand. Like more than one sentence and some text editing.

i been in ac four a few years i just started with the working on the freezer im having problems with a 404a -10f box its stops at 20f i have clean cond and evap good air flow my suc was 32g

What does this mean? Measure your evaporator air in/out temperatures and post it here.

held it would not go any lower is that normal for a copeland semi hermetic i thought that it should be able to pull a vacuum with no problem could this be just compressor problem the amps were normal

Did you adjusted your LP switch that compressor could go in vacuum, for this test?

and btw what is the most common problems with the freezer that they seam to be i seen this a few times were the boxes 20f no colder and it seams that every things is good but it cant be give me a clue LOL thanks

In order to evaluate what is going on, we need at least following measurements:

• evaporator air in/out temperature
• condenser air in/out temperature
• Suction pressure
• Discharge pressure
• Suction line temperature at TXV bulb location and near compressor
• Discharge line temperature near compressor
• Liquid line temperature before TXV
• Compressor model #
• Compressor running current

[Shibhrac]

First thing Pulleing downn the the pressure to vac.. Levels was not and will not be a good practise specially in positive displacement compressors.secondhy why do we have to get zero pressure in the system.