Breaker Tripping Almost Immediately (2003 Sweetwater Bahia)

[langetr1955]

Hello folks,  another circuit breaker trip posting.   Hopefully the experts out here aren't tired of them yet.

Sweetwater Bahia (2003).   Has run pretty flawlessly for seven years, except for a new circ pump and thermostat. 

Today the 50 amp GFCI breaker at the fuse box was tripped.   I shutdown the outside cutoff switch and then recycled the breaker at the fuse box.   When I turned the cutoff switch back on the GFCI breaker trips pretty much immediately.   

I've seen threads here that discuss ozonators, heaters and pumps causing breakers to trip, but I'm not sure these types of trips are as immediate as mine.   My tub generally goes through about ten seconds of "boot-up" before the pumps and heater kick on.   The breaker is tripping quite a bit before that.   

Any thoughts on potential causes for such a quick trip?    I plan on doing some basic unplugging of components later this afternoon to see if the trip may be caused by a bad component.   

Thanks in advance for your expertise.   

  - tim
 

[VTXMAN]

The heater will receive voltage almost immediately, disconnect the heater wires and see if the breaker will hold.

[langetr1955]

A progress update.  No luck yet.   Here is what has been done thus far. 

Pulled off all four heater wires - still trips. 

Also pulled off the two ozonator wires - still trips.

I see there is a Buss SC-30 fuse on the board.  Any idea how to tell if that's blown?  (Is it noticeable?)   
http://www.cooperbussmann.com/ProductInfo.aspx?productID=6036

I have two jet pumps and one circ pump left that I can disconnect.   I can easily do that too.   

[langetr1955]

Another update.   Too wierd.   I pulled the fuse mentioned above and looked at it.  (Like I know what I'm looking for.)   
Put the fuse back in and tested it, just for fun.
It worked!!   

I have no idea what to think of the reliability of that fuse, but I sure was surprised at the fact that it all powered up.   

So, I shutdown again and hooked up everything that I disconnected.   

Powered it back up and it still worked.   

The only thing I can point to is re-seating the fuse.   Tell me, what are the odds? 

Thanks for the advice.    - tim   

[mjk4700]

I have  a 2003  Bahia tub, lost power to control panel.  I have power into circuit board but will not power on?  Any ideas?