[Amps] 220V wiring: Was Question about safety ground connection

[Mike McCarthy, W1NR]

Everyone.  When talking about a 220V outlet FORGET about what it may or may
not do at the breaker box.  A 3 prong 220V outlet is 2 hot and GROUND.  A 4
prong 220V outlet (also called 110V/220V) has a neutral added.

You cannot safely connect a 110V device to 1/2 of a 3 conductor outlet.  In
this case, you are using the ground as neutral and are in violation of the
National Electric Code.

Breaker panels may or MAY NOT have neutral and ground bonded.  The breaker
box in my radio room, by the code, has separate neutral and ground busses
connected to the main entrance with a 4 conductor feeder.

This is what is mandated by the NEC.  It is not dictated by the breaker box.

Your safest bet is to run 4 conductor wire and outlets.  All new ranges and
dryer circuits must be 4 wire.  As far as I am concerned, all new amplifier
circuits should be too.

Mike, W1NR