Shore Power Issue

[MarkMuck]

I came back to our 92 Silverton yesterday and the A/c was off. It tripped it's main breaker.
I turned it on again and it did the same thing.

I eventually swithed the power cords of our 30 amp services. Then the a/c worked fine but
the other side of the service tripped it's main breaker.

I'm thinking one of my old shore power cords has developed a problem.... Is there anyting else I should be looking at ? Thank you..

Mark

 

[captgoerge]

120 volt or 220 volt lines?

 

[cwms]

Is it your power cord or the dock outlet that has a problem?

 

[pdecat]

open each cord connector and look for corrosion. do the same with the boat inlet socket.

 

[MarkMuck]

It's 120 volt line....

Thnx.
Mark

 

[abdiver]

I didn't quite follow that: when you swapped power cords, did the problem follow the power cord or stay with the panel?

When you swapped power cords, where did you do the swap? Did you leave the cords plugged into the dock the same but switch the cords at the boat? If you swapped the cords at the boat, and the problem swapped panels, then it implies that a problem developed at either the dock power connector or in the power cord itself.

If you swapped the cords at both the dock and the boat and the problem swapped panels then it implies that the cord developed a problem.

If you swapped just at the dock then the problem would have to be in the dock power.

When the breaker trips, is there a reverse polarity light that is lit? Many electrical panels have a "voltage" sense as part of the breaker so it will trip the breaker if a reverse polarity is detected. This circuit looks for a voltage to be present on the "neutral" lead with respect to ground. This can happen two ways: one is to have the dock plug (or power cord) wired backwards but the other way is to have the neutral lead "open" somewhere between the breaker panel and the main power distribution for the dock. When this happens the power comes in the "hot" lead as it is supposed to, then out the "neutral" as it is supposed to, but because the connection to ground is broken the neutral will end up "hot" and will trip the voltage sense coil of the breaker.

Rod