50A rigs and wire sizing

LittleBill wrote:

Bob Landry wrote:


Also, the reason we see so many burned neutral wires, aside from loose connections, is the wire is undersized at installation. Folks, neutral is a current carrying wire. That is why when you go to a breaker panel for a 50A systen, there are three breakers. All current carrying legs have to be protected. If you disagree, tell me where the current flows from to get to the hot wire when a device runs, it's not through ground. In a 50A circuit, the 120V is referenced to neutral. That means that at any given point in the cycle, the neutral has to carry the same amount of current as the hot leg so it has to be the same size wire. Why do you think that when you buy romex or marine wire for AC, the wires for hot(s) and neutral are the same size? It's not because it's easier to manufacture that way, it's because it's required to handle the current load.

well i guess someone had to be wrong, guess its bob

Bob, there are not 3 breakers for single phase 50amp/240v

there is no breaker for a neutral wire, there is no point since the hot side is protected

now on 3 phase 208v, there are 3 breakers but there is also another wire. i think this is where your getting confused

Nope, I guess if someone has to be wrong, it's you. In marine 50A shore power applications, the main breakers are three pole and ganged so that everything opens at the same time. ABYC requires it because neutral is a current carrying leg. Under your scenario, there should only be one breaker for a 30A input since the hot is protected. On the 50A panels that I work with, neutral is switched by a breaker and then goes to a buss that is common for all of the neutrals, but it is on a breaker where it enters and is distributed. Maybe it's different in your world.