CJW8 wrote:
If I remember correctly, the total of all branch breakers shouldn't exceed 125 percent of the main breaker size. Someone more current with the Code may correct me.
In all my years in the biz, have never heard remotely like that. It's possible and very common to have the total of branch breaker ratings in a panel to far exceed it's mains rating and it works because of diversity - ie., the branch breakers are never all running at or near their ratings simultaneously and/or for long enough.
Paneboards in an RV would be covered by art. 551 in the NEC and I don't recall any rules governing total number of breaker spaces or ratings. I think converter/panel manufacturers probably provide a min. number of breaker spaces to comply with the various circuits that are specified under NEC 551 using 1" wide breakers.
For a 30 amp RV you have a 20 amp AC breaker and 4 or more 15 amp breakers totaling 90 amps and it's rare that a 30 amp main trips.
