Super Cold Machine Blowing Fuses

[buchhla]

Hi, I have a ~ 3 year old AB Super Cold machine thst just stopped working a few days ago. It just blows the 15A fuse on the panel as soon as you insert a new one. I am not currently running the water pump option on it, and I tried disconnecting the air cooling fan.

Where do I need to start looking to see if it is the controller board or the compressor?

[senormechanico]

If you don't see any wiring defects, I'll go with a 99% bet that it's one of the driver transistors.

[buchhla]

So I assume that is on the danfoss controller board? Assuming they are not SMT, I could easily replace a few transistors. The more reading I have been doing is pointing me somewhere in the control box.

If this is not a easy thing to fix, does it make sense to upgrade to the AEO version of the box since I am planning on leaving cold water for warm later this year?

[Joli]

Where are you located? Sometimes in the North the sealed compressors have a short life becuase they sit so much of the time. I've seen more then one die a premature life. Sorry.

[senormechanico]

Originally Posted by buchhla

So I assume that is on the danfoss controller board? Assuming they are not SMT, I could easily replace a few transistors. The more reading I have been doing is pointing me somewhere in the control box.

Try unplugging the motor. Does it still blow fuses?
If not, motor. If so, board. The motor could still be the cause of board failure.
Worth a try if output transistors are shorted. FET's are reasonably priced.
Digikey is a good source.
If you replace transistors and it blows again, dump it.

[onestepcsy37]

when i installed my super cold machine about five years ago i had a problem with it not starting. called waeco and they diagnosed it over the phone as the control board. sent me a new one by ups the next day. they were very helpful.

i nearly always try to fix things myself, but in this case calling waeco may be the cheapest solution....

[JiffyLube]

I've read many times that two things kill the module. One is heat, and they other is voltage spikes. Heat can be dealt with my placing the compressor is a better ventilated location, and providing good incoming and outgoing air flow with fans. Voltage spikes can be almost completely dealt with by wiring the compressor directly to the house battery, and including a circuit breaker as close to the battery as possible. Connecting the compressor through a branch circuit is not the recommended method, but a person might get away with it for awhile.