"Pop`" wrote in message
news:7PECh.962$CG5.186@trnddc03...
Herb and Eneva wrote:
Will someone please explain the difference between the grounding
wire---white, and the grounded wire---green, in a circut? They both go
to the same busbar.

Lots of reasons; it -can- get complicated to explain, but here's one
situation:

Any exposed metal in what's called Class 1 equipment (Stove, fridge, etc)
must be grounded. The green ground wire is used for that ground. Its
sole
purpose for existance is safety. In addition, the blk/wh wires are NOT
connected to the exposed metal; doors, cabinet, legs, etc etc. in
equipment
in today's equipment; it was different "yesterday". The reasoning here
has
to do with "polarity" of the hot/neutral. Should it be reversed, then the
exposed metal would become "hot".

Using the "neutral" as a ground was generally used in two specific cases:

1) "High Current" 220/240 volt appliances which means stoves and electric
dryers. Generally speaking, the neutral normally carried a tiny fraction
of the total current. In "modern" stoves, that's just the oven lamp and
the clock/electronics. In the dryer, the motor is still often 120. The
GROUND/NEUTRAL connection was quite solid. The users definitely had
contact with the neutral but in practice it just didn't cause problems.

2) The old style "AC/DC" radios and TVs. It was routine for the chassis
to be connected to the neutral. That's why plugs are "polarized." BUT
these things were insulated and the users didn't actually have contact with
the neutral wire or metal parts that were connected. Now, things are
"double insulated."