Keezer or kegerator

[NBBrewer]

I have a chest freezer that I got free. I planned on fixing it and turning it into a keezer or a fermentation chamber. It does not cool but the compressor motor is running and gets warm. I thought it was the relay. Try to find a relay for an old freezer. I was going to test the compressor by bypassing the relay momentarily. This seems inheritantly dangerous. Is there any way to safely test a compressor without a relay?

 

[day_trippr]

If the compressor is running there's nothing wrong with the start relay or capacitor.
I would suspect the unit is unencumbered by refrigerant...

 

[NBBrewer]

Thats the thing. I don't hear the classic click buzz of a compressor kicking on. I just wanted to rule that out before I turn it into an ale fermentation chamber.

 

[day_trippr]

Pull the line cord, wait five minutes, then plug it back in...

Cheers!

 

[NBBrewer]

Pull the line cord, wait five minutes, then plug it back in...

Cheers!

Hey thanks Day Tripper I think it may be a stuck valve or ultimately low refrigerant. If the relay wasn't working it might run the motor but won't start the compressor.

 

[day_trippr]

The motor and compressor are one integrated unit. If the motor is turning, so is the compressor...

Cheers!

 

[NBBrewer]

The motor and compressor are one integrated unit. If the motor is turning, so is the compressor...

Cheers!

So it may be leaky valves or a bad capacitor.

 

[day_trippr]

The capacitor is only used to start the motor.
The most likely root cause is the system bled out...

 

[NBBrewer]

The capacitor is only used to start the motor.
The most likely root cause is the system bled out...

Thanks Day Tripper The way I understood it was the relay and the capacitor start the compressor and once the relay warms up it switches to run mode. If a valve is leaking because it doesn't seat properly the pressure differential equalizes and no compression can occur.

PS I am by no means an HVAC tech. I am just trying to approach it that way. I had an HVAC guy tell me 2 fridges were done and were low on refrigerant. One actually needed a new thermister and the other needed the defrost drain unplugged.

 

[bracconiere]

defrost drain unplugged.

?? i got a really old fridge i still use for my kegs....20 years old or so, what exactly did that take? i was thinking maybe the defrost coil, but now i wonder.....

i drilled a 3" hole in the bottom of the top freezer and put a fan in it, now it actually shuts off once in a while!

 

[NBBrewer]

?? i got a really old fridge i still use for my kegs....20 years old or so, what exactly did that take? i was thinking maybe the defrost coil, but now i wonder.....

i drilled a 3" hole in the bottom of the top freezer and put a fan in it, now it actually shuts off once in a while!

The drain was freezing...

 

[NBBrewer]

Every now and then I check my freezer temp, my fridge temp and if any water is draining from the freezer. Surely the % humidity in the freezer(27%) reaches some kind of minimum (perhaps based on the dewpoint) and if i see no water draining( defrost heater comes on every 6 to 10 hours) then maybe the defrost drain is plugged.

 

[day_trippr]

Thanks Day Tripper The way I understood it was the relay and the capacitor start the compressor and once the relay warms up it switches to run mode. If a valve is leaking because it doesn't seat properly the pressure differential equalizes and no compression can occur.

PS I am by no means an HVAC tech. I am just trying to approach it that way. I had an HVAC guy tell me 2 fridges were done and were low on refrigerant. One actually needed a new thermister and the other needed the defrost drain unplugged.

I've done enough research and hands-on work on various cooling systems to know how they work - and if your compressor motor is spinning, that means the start relay and the start capacitor both did their jobs and should not be suspect of anything untoward. The start relay cuts the start capacitor totally out of electrical function as soon as the motor approaches it's running RPM, and that's the end of the capacitor's function until the next start. I've said it frequently here: the problem lies elsewhere.

Assuming neither the condenser or evaporator or any of the interconnecting tubing has been breached, that leaves the integrity of the compressor itself. There is indeed a simple reed valve inside the compressor on the suction port to prevent backflow during compression and exhaust, and while that could fail, it's unlikely when compared to the high-pressure seals.

If you want to try to bring that system to life, take a look at my recharge thread here. At the very least you can examine the suction side pressure and even top-up the refrigerant if it's low...

Cheers!