Guys there are no problems here so long as the wiring is matched to the breaker for it. Even if the shore wiring is only rated for 20A it's protected by the 20A breaker. So it's safe no mater what your main breaker is. Just don't draw more than 20A unless you want to pop it.
And a 30A shore breaker with 30A wiring could also be plugged into a 20A main breaker without any problems. Just like in your house you have the 100 or 200A main breaker feeding a bunch of 15's and 20's...That's the point of breakers, to protect their branch from potentially higher current available on the bus.
09-29-2012 06:37 PM
Not a problem. The shore power will only allow a 20amp overload. Since you have a 30amp main theshore power breaker will trip first and your 30amp main can withstand any overload. If it were reversed the would be a problem. 30amp shore with 20amp main....bad
09-29-2012 04:54 AM
Re: Different size Breakers
Not a problem if your shore power cord is rated for 30 Amps. Normal shore power cords are. A household extension cable, even an "outdoor" one, is just 15 or 20 amp.
09-28-2012 10:55 PM
Different size Breakers
Shore side power Breaker 20 amp, Boat main panel 30 amp. Problem?
Should I downsize Boat panel to 20 amp also? Thanks.