jake14mw wrote: wwhitney wrote:
jake14mw wrote:Can you help me understand this?
This is a little bit of a grey area. The breaker's #1 job is to protect the fixed installation, i.e. the building wire and the receptacle. With 6/2 NM (btw, not allowed outdoors) and a 6-50 receptacle, a 50A breaker does that fine.
Some equipment manufacturers will also ask for a particular breaker size to protect their equipment. In the case of the EVSE you posted, its manual calls for a 40A breaker. Whether the NEC requires that instruction to be followed is open to interpretation (110.3(B)).
OK, you guys are confusing me now!
Thanks for looking that up for me. I'm thinking that if the manufacturer calls for a 40A breaker, that's what I should do?
It sure wouldn't hurt
More than likely you'd probably never need 50 amps anyway but I'd also agree with running 6 gauge wire, so you'd never probably have to replace it. 6 gauge may also be a bit
more efficient in that running 40a it should never get warm(loss in efficiency) of course breakers also get warm when running near their max rating but as the Leaf only draws 27.5a and the EVSE only outputs a maximum of 30a, even a 40a breaker will probably never get warm.
Breakers are somewhat cheap and easy to replace, a 40a breaker will help protect your 30a EVSE a bit more than a 50a breaker, no real advantage to going with lighter gauge wire, well other than cost