I think it fair to say that it is common knowledge amongst sparks to direct all live conductors and associated protective conductor through a common aperture in a ferromagnetic enclosure. So I want to direct attention only to domestic installations where load currents will be relatively light so that I can understand better the consequences of not doing so in that particular environment. I refer to regulation 521.5.1 and item 4.17 on the condition report inspection schedule
That is like a rather more business-like version of my welder demo. I'd have struggled to see 2 degrees rise in the metal with my set up. Based on comparisons of touching with fingers, you need to send the nominal 150A welder current round at least twice through the hole to get something in feeling range,and then the cable is also getting warm as part of the normal run of things. Nice to have the results backed up though, and I stick with the rule of thumb that upto to 30A through a normal galvanized back box will do nothing worth worrying about.
That is like a rather more business-like version of my welder demo. I'd have struggled to see 2 degrees rise in the metal with my set up. Based on comparisons of touching with fingers, you need to send the nominal 150A welder current round at least twice through the hole to get something in feeling range,and then the cable is also getting warm as part of the normal run of things. Nice to have the results backed up though, and I stick with the rule of thumb that upto to 30A through a normal galvanized back box will do nothing worth worrying about.
