Fixing Keg Cooler

[guinsu]

A friend who works at a local bar was able to get me a 4-tap keg cooler that kicked out on them about a month ago. For the price I figured I could find some way to get it working and use it for cold crashing and maybe some serving. It fits 4 full size kegs and at least 8 cornies.

I've cleaned it up and now am trying to diagnose the problem. I am decent with a multimeter but am not experienced with refrigeration. Right now the fan inside runs when I plug it in and it sounds like a relay near the compressor keeps tripping on and off. I know having the exact model would help but are there any general guides I can use to get started with this? I'd like to get some idea what the problem is before I call in a pro.

 

[Bjornbrewer]

is the relay chattering (switching back and forth real quick) or switching every couple seconds?

you might want to call in a pro just to check the pressures (if that's even possible, it may be a closed system).

I'm no expert, just a couple of starting points for ya!

 

[bendavanza]

I'd ask the question at micromatic's forum, there are a lot of reefer experts there. When mine died, the compressor fix was $800 so I just scrapped the case and kept the towers, fans, etc. You might get lucky and just be able to replace the start capacitor.

 

[guinsu]

The relay is switching every few seconds, any idea what that means? I will check out that forum. Worst case I scrap it, I got 2 towers, a reg and 4 keg connectors out of it.

 

[bendavanza]

guinsu
Mine lasted about 1 year, a bevair 3 door, which had a hard life. Yeah I kept the 2 towers, drip trays, connectors, and even the flex tubing for cooling the towers, and I used the thermostat to repair another kegerator. Parts is parts, but I do hope you have luck with it.
A Supco start kit might solve your problem, know the voltage and hp of the compressor, and pick one up at a U fix it appliance shop. Around $25 and it may solve the problem unless the compressor is hosed.

 

[Bjornbrewer]

The relay is switching every few seconds, any idea what that means?

It sounds maybe like the temp sensor or sensing circuit is bad.

Worst case I scrap it, I got 2 towers, a reg and 4 keg connectors out of it.

Not a bad deal!

 

[TomRep]

If it's every couple seconds, I would say it's low on refrigerant. What name brand cooler is it? I just picked up a Beverage Air for free on CL and am in the same boat. Luckily it takes r134 and I'm an auto tech, so it won't be a problem to charge. However, it is a closed system and has no fittings, so I am working on a way to add one. If things go well it will be done tonight and I'll bring it to work tomorrow to charge it up. If yours is a Beverage Air, I can let you know what fittings I used to do it.
tom

 

[guinsu]

It's made by Superior Product of St Paul MN. It looks like there is a port on the line to recharge it if that's the problem. There is some corrosion on it though.

 

[ncgardenfreaks]

I work on commericial resteraunt equipment and coolers for a living so I may can walk you thorough some of it. Most of those coolers dont have a pressure control on it to know if its low on gas or running to high of a pressure. More than likely it is the overload on the compressor called a clicks-on. It will be on the side of the compressor around the electrical box or even in the box. Check and see if that is what is kicking in and out. If it is that it could be a bad compressor, start relay, or start capacitor. To see if its the compressor you can check continuity between the poles on the compressor to see if it has an open winding on the motor, but also check them to the compressor case(you may have to scratch the paint off to get a good ground) to see if it is shorted to the casing. You can also look on the refrigeration lines coming out of the compressor and see if there are any sensors or taps with small tubing running to a controller. These would be the pressure controls. If they are just sensors hooked onto the lines you can unwire them and check continutity to see if the switch is made or broke. If its an external control most of the time you can take the front cover off and manually override with a screwdriver. Looking for any oily spots around the compressor and tubing can be a sign of a refridgerant leak. Let me know if this helps any.

 

[guinsu]

Thanks for the advice, I finally had a chance to check out the cooler. As long as I was testing the right contacts there is resistance between the two poles of the compressor as well as the casing and the poles.

The way it seems to be operating is a relay clicks on and the fan goes into high for about 15 seconds. Then it clicks off for 4 seconds and the fan goes to a slower speed. This repeats... The lines didn't feel like they were cooling off much in the minute or so I had it on.

Where the line comes out of the compressor there is some sort of cap or nut on top of the line and facing the rear of the unit looks like a threaded port to refill. I didn't see anything that looked like a sensor hook up unless it is inside the cooler itself near the fan (I didn't disassemble that area).

Any further advice you can give?

 

[ncgardenfreaks]

If you are getting resistance from the poles on the compressor to the casing then the motor in the compressor is shorted to the case. Mark and remove the wires from the compressor and recheck the poles to the case. If you still get resistance then it will have to have the compressor replaced in it. From what it sounds like that is the case. I have never seen a unit with anything other than a single speed fan on the condenser coil (which is with the compressor) so more than likely it tries to fire the compressor and pulls 50+ amps of power for second which slows the fan down due to voltage drop and when the overload kicks out the fan speeds back up. Let me know what you find out.