not in trouble yet- but close

[in house worker]

I work at a school as maintence man. I got my refgerent cert. about 2 years ago. I've had 3 freezer problems in that time. About 4 years ago a company evacuted a freezer that had 502 ref and replaced it with AZ-50. the last few days its been running about7-10 degree F. I've cleaned the coil today with coil cleaner and water. It made no difference. My pressures and line temps are 320psi and 115 degrees F on the discharge and 28 psi and 66 degrees F on the suction side. The out doors temp was 81 degrees F. The condensing unit is in a vented storge room with the room temp of 95 degrees F. I added a shot of freon to it which did not help. the temp in the freezer is standing at 10 degrees. Is pressure and the hi side is to high? Is that why the freezer temp is warmer than it should be?
I know the defrost works an the evaperator coil is not iced up. I'm out of ideas.

[R12rules]

Welcome Friend, you've arrived! You have come to the right place!
You are gonna love it here.

I think the ambient temp is too high for that unit to work right in.
507. Not a good choice, unless your on Gilligan's Island and it's all you've got to work with.
I assume that vendor who replaced a real refrigerant like 502, with this junk ... I guess they also changed the compressor oil?!
If they did, then your system has POE in it. POE oil likes to do funny things to cap tubes when it gets too hot.
And "too hot" can be defined as what is in your storage room right about now!
Your goose may already have been cooked. So to speak.

You mentioned the discharge line temp. Give us the liguid line temp where it is about to enter the filter drier. Check to make sure there is NOT a temperature drop ACROSS the filter drier.
Is this a cap tube or an TXV system?
Give us the suction line temperature measured six inches from the compressor can itself.

If your not sure about the charge being right, recharge it. And when you do so, replace the filter drier.

I trust you are comfortable with doing these proceedures.
if yrou not, you have two choices.
1) ask and we will walk you thru it.

2) get a vendor in there to do it and watch them do it. Ask lots of questions. We'll tell you how they should be doing it, step by step. You'll drive him crazy! :p

Take those temps and get back to us. Take it slow and easy. We are here for you.

You may end up replacing the cap tube, the filter drier, changing the compressor oil AND recharging the system by weighing in the right amount of a different refrigerant! NOT 507.

Hope this helps.

[Edited by R12rules on 07-13-2004 at 01:06 AM]

[in house worker]

It has a TXV I think because it has a saleniod valve in the line. In talking to the company the said that it is a drop in ref so the did not evacuate the added to the 502.
and that was in 99. But getting back to the freezer at 7 am the temp of the freezer was at zero. At 10 am it went to defrost and it never got below 5 degrees.the temp of the line was taken within a foot of the compessor. I can not find any tags in the box that tells how big andhow much freon it needs. the only tag is on the comprssor.