You don't need a main breaker. If you feed your unit from a generator
, the generator
will have a circuit breaker to protect it's outlets. You just have to make sure the wiring external from the generator
thru to your new circuit breakers is sized to the generators outlets. If the generator is a standard duplex outlet it will have either 15 or 20 amp rating. If you use 12 awg wire you will be covered.
Same goes for a connection at a trailer park. Use the duplex outlets if you have a 12 awg wire. If you plan on using the 30 amp outlet at a park then you will need 10 awg wire from the park outlet to your new circuit breakers.