[SML] wire colors

[billn at peak.org]

> 2. "NEVER" interchangeable is the theory, and quite correct.  However,
> in practice, you find places like a certain shiny new city convention
> center where I once worked.  The first time a crew of IA electricians
> did a trade show, we found that all the floor pockets had 4-pin
> connectors for the 208-wye-120 and for the 480-wye-277 services.  The
> building management's "electrical consultant" who was a retired
> residential electrician, explained to us that "Ground and neutral are
> the same thing" and thus he had specced the 4-wire services on
> principle and to save money.

He may have specified what is a "shared neutral" configuration - which is not
the same as "ground and neutral are the same thing".

Anyone who thinks they are the same should perform a simple experiment. Take a
Source 4 instrument and disconnect the common/white/grounded conductor in the
plug (make sure to insulate the bare end), then plug it into an outlet. You
will find the lamp does not illuminate.

The equipment grounding conductor (green) is not part of the electrical
circuit. It is the safety conductor to protect people in case of an electrical
fault in the equipment.

Bill