I have a Formula 336 with shorepower, and everytime I plug it in to my dock the breaker inside the cabin on the main AC control panel trips. It works at other docks, just not mine. The reverse polarity indicator is not lit, and I know the shorepower on the dock is wired correctly. Any ideas?

If it works fine at every other dock besides yours, why do you think yours is still ok?

Yeah why . Sh\ure would seem there is something wrong with yours.

I guess what I meant is I can't figure out what's wrong with mine. Everything looks/tests OK...I'm at a loss...???

Change the breaker. Use a new breaker, it probably is ok without any load but trips under a load. If the is not the problem you have to meter the line for a break or short.

Yup, breakers can croak after an overload. Then look at the plug on the post. Water, spiders , something causing a short when you plug in.

Can you turn off the breaker and then hook up the power,does it still trip?
Do you have every independent device breaker shut off, does it still kick the main?

I'm not calling you an idiot I just had to ask the basic

Another question do you take that cord with you or do you use another when you travel?

When you are saying cabin are you talking about cabin in your boat? If so then the breaker that is tripping is not the problem. You have a problem with your shore power.

If the breaker in the boat that is tripping is a GFI breaker then you probaly have either a ground or neutral problem.

Give me a little more info

Power cord is OK..it works on other docks.

The breaker that trips is on the main power control panel in the cabin of the boat. It trips with all other breakers off.

Procedure I use is: all breakers on panel off, plug in shore power cable, turn on main breaker (it immediately trips). \

There must be some problem with dock wiring...I just can't figure out what. There are only 3 wires!?