Questions about Beverage Air freezer

[BlueVanACD2005]

I recently bought a used 'E series' Beverage Air freezer, and needed to know a couple things about it.

First - the fan inside the freezer doesn't run, but it does work and is hooked up (to the BLUE wire from the timer thingy). I was wondering when it's supposed to run (I would think it should run almost all the time - to circulate the cold air inside the freezer).

Second - maybe about a minute after the compressor shuts off, it emits a high-pitched sound for about 5 or 10 seconds. It sounds like it's coming from one of the lines around the compressor. What would cause this? ('H' valve or expansion valve?)

That's all I can think of for now.....

Thanks in advance for the help.

[BlueVanACD2005]

I realize now that 'E Series' must not mean much, because there are a lot of different models within it. I couldn't find a model number, so I took a couple pictures instead:

EDIT: won't let me put pictures up, says they're a URL, and they're too big to make them attachments.

[chillin out]

The 'singing' noise you hear when the comp goes off could be the gas passing back across the valves (which it's not supposed to do).

PM me your picture links and I will post them for you (there is a post number you have to reach before you are allowed to post urls).

Chillin

[BlueVanACD2005]

PMed you.

Could the 'singing' be due to a kinked line (particularly the small high-pressure line)?

[chillin out]

[BlueVanACD2005]

Can expansion valves go bad? (I assume this is the valve you were refering to when you said the gas was leaking past 'the valve'). Does it just need adjusting?

I also noticed it doesn't get as cold as it's supposed to. I let it run all afternoon with the thermostat on the warmest setting, and it never shut off. It got down to 30 F pretty quick from 70 F (maybe 20 minutes or so), but then it didn't get much colder - in the next hour or so it only got down to about 25 F. I just shut it off, realizing it isn't right.

[chillin out]

No, the valves I was talking about are inside the compressor.

Easiest way to check if the comp is working properly is run it for 10 minutes and then switch it off, now put your hand on the suction pipe (the colder of the two) about 2 inches from the comp. If it starts to get hot quickly then the valves are passing so its knackered.

Make sure the fan on top of the freezer is running and the grill is clean.

Chillin

[Fire and Ice]

Hi
I work on these things all the time. The "blue" wire on the timer is hooked into the door switch circuit and there is a fan delay switch to keep the fan from running when the evaporator is too warm-after a defrost.
Need more info - let me know
Fire and Ice

[BlueVanACD2005]

Just curious - What might be the consequences of putting R134a in a R502 system?

[Electrocoolman]

R502 compressor/system would have mineral oil inside. R134a is incompatable with mineral oil, unless blended with other refrigerants to make it a 'drop in' refrigerant (i.e. useable with mineral oil).

Also refrigeration capacity would be less with R134a. If you were going to go to the trouble of changing oil / flushing / testing, then R507 would be a better gas (more akin to R502).
A drop in would be a lot easier to use, but I don't know what ones are available in your neck of the woods, so am unable to recommend a specific one.

[BlueVanACD2005]

I'm pulling up this thread again to ask another question - Could I replace a freezer compressor with a air conditioner compressor (provided they are the same HP and refridgerant). I wanted to know if it would pump enough pressure.

This 'singing' is getting worse, and this freezer is very inefficient with the freeon running back through the compressor. I want to avoid a new compressor for now, mainly because I want to avoid putting money into the freezer.

[BlueVanACD2005]

It's worse than I though - if you let it run, then turn it off, then you can actually hear the rerigerant RUSHING back through the compressor. It then slows down, and changes to the 'singing' I've always heard before. I removed the compressor from the A/C unit, and it looks very simaller.

[BlueVanACD2005]

Well, it worked. I took a R22 A/C compressor and put it into a R502 freezer. I then charged the freezer with R134A, and the whole thing actually works now. It was a long shot, but hopefully it will work for quite a while now.

I can blow through the old compressor both ways. I assume this proves the valves inside are shot? It doesn't matter now I guess.

[fireandice]

Did you have to change the oil to poe?

[hillbillywillie]

quite honestly, I didn't think the a/c compresser would work in a freezer with different refrigerant to its designed spec.
Let's know how it does.