On Thu, 4 Jan 2018 13:01:34 -0800 (PST), Its Me
wrote:


That's because electricians are schooled on the mechanics of wiring, but not theory. If a device's tag says it draws 30 amps, they know what size and type wire for the run to it (or where to look in the NEC book to find it), breaker size and type, conduit or not, etc. I'd bet close to half don't understand that the two legs are actually 180 degrees out of phase. Their exposure to theory is very brief, then it moves on to mechanics. Nothing wrong with that. The book tells them what size neutral, too.

That was true in places where training is left to the unions but
places that get actual continuing education for the new guys (and the
old guys) will be exposed to a lot more theory.
Union training is basically the old guys dribbling out what they know
to the new guys over 4 years. Very little new ever penetrates that
cycle.
I remember trying to explain triplin harmonics to a bunch of union GSA
electricians and having them tell me how long they had been wiring and
how I was just a snot nosed kid who didn't know ****.
A week later when their neutrals were burning up, the manager told
them they needed to listen to me.
Nobody had ever seen electronic ballasts and switching power supplies
before the 70s and 80s but they learned.