Engine Drive Refer Madness

[Sandero]

I am trying to diagnose the cause of my circuit breaker popping off on my Grunnert Caribbean 75 engine drive refer.

The refer worked perfectly for years and then last week after 40 minutes or so it popped the breaker. I thought the breaker was shot. I replaced it. Without the engine running if I energize the clutch I can hear the coil pull the clutch plates together and let go when I switch the power off. So it seems it was NOT the breaker.

The compressor seemed to "run" for shorter periods and now it will only run until the breaker pops for 15-20 seconds. So the coil or clutch seems to be drawing too much current after a few seconds and overload the breaker. Can this be related to the compressor function or is it isolated to the clutch part?

Can someone explain what is going on here and if I can repair or replace the clutch? Or is this a symptom of the compressor not functioning for some reason... gas pressure or whatever??

What tests can I do to determine where the fault is?

Thanks!

[Tropic Cat]

It sounds like the coils on the clutch are shorting.

This type of system can be a real problem. I know... I have one as well. Many of these engine driven systems used R-12 refrigerant which was banned for consumer purchase years ago. Professionals should still have some, but it will be incredibly expensive to recharge a system these days. R134 conversions are not possible according to Nigel Calder's book as the oil types used in the compressors are different.

[Fishspearit]

Originally Posted by rickm505

R134 conversions are not possible according to Nigel Calder's book as the oil types used in the compressors are different.

Check the date on Nigel's book. Although I'm not a refrigeration expert, I believe that was the thinking when R134 was first being mandated and R12 was being phased out. What the industry found out was that as long as the system is evacuated, the ester oil used with the 134 does not cause a problem with small amount of oil left from the R12.

Sorry Defjef, I don't know about your problem. Hopefully Richard Kollman will find your post soon and help you out.

[Tropic Cat]

That's weird. I have a 2005 "third Edition" of "Boatowner's Mechanical and Electrical Manual" On page 460 he says that 134 is incompatable with the mineral oils used in R-12 systems. Now, that's some 10 years after the R-12 ban, and one would think Mr. Calder would have this right.

Are you saying that Nigel is wrong?? Perhaps Mr. Kollman can clarify this.

[Fishspearit]

Originally Posted by rickm505

Are you saying that Nigel is wrong?? Perhaps Mr. Kollman can clarify this.

I would be hesitant to say that Nigel is wrong. I thought that I read this in Kollman's book, but it's on the boat and I'm at home right now so I can't verify it. They convert cars from r12 to 134 without changing the compressor.

http://kollmann-marine.com/