818 shutting down

[Brian Oshman]

Wrong move. The wire is probably #4 which is only good to 80 amps. You need #2 for a 100 amp breaker. That is not the fix especially if it was running fine prior to the problem. You just created a fire hazard.

Put a 80 amp back in and find the real problem.

[Natureboy]

His wire on the secondary would be #6. On the primary he probably has #3. At least that is how I set up my UB's.

I think an 818 only draws like 68 amps on the secondary.

I still say it was just his original 80 amp breaker was weak. I have run them with 100 amp breakers before, but personally like Brian said, you should replace the 80 amp one with a new 80 amp one and see if it holds. The bed should not draw close enough to trip it unless something is wrong.

[coldgyn]

I'll recheck the draw. I knew I'd read in the past natureboy had used 100's. I'll put in a new 80 and see what happens, just for safety sake.

[Brian Oshman]

The wire size determines the max breaker size. If you have #2 ran from the panel to the transformer then the 100 amp breaker is fine. If you have #4 ran then the 80 amp is the max breaker size.