AC power when switch is off?

[rdl0100]

My AC system in my boat has always worked just fine. However, this year when I put the boat in, and hooked up the shore power, the voltage meter on the electrical panel showed 120 volts, even though the master panel switch was still turned off. When the switch was turned on (a 2 pole 30 amp single switch) the items connected to the panel, i.e. the microwave, outlets, worked. When the switch was turned off, the appliances went off, but the meter still showed that there was 120 volts. In the past when the main switch was turned off, the meter dropped to zero, which is what I would expect. I could only get it to turn off by disconnecting shore power. I don't know what is happening. It may be that the main 2 pole 30 amp breaker/switch is bad. Could that be it? Any other ideas or suggestions?

 

[mike_i]

Just a guess but maybe the meter is showing there's 120v shore power and is wired before the master panel switch. Is the master panel switch on your boat?

 

[rdl0100]

I don't think so because it has worked appropriately in the past. I.e., even when the shore power is hooked up, when the shore power switch on the electric panel was switched off, the meter showed zero volts. This is something new this year. Thanks

 

[dingbat]

It may be that the main 2 pole 30 amp breaker/switch is bad. Could that be it? Any other ideas or suggestions?

Never heard of a breaker failing closed but there is a chance the contacted arched, welding themselves closed

Easy enough to check. Pull it out and put a meter on it

 

[mike_i]

Is the electrical panel, meter and master panel switch on your boat?

 

[FunInDuhSun]

My boat has a 30 amp waterproof breaker next to the shore power inlet plug. If that breaker is off, the 120v panel has no power.