On 6/23/2017 5:06 PM, Boris wrote:
I read all your replies (thanks), and understand the the differences
between 3- and 4- wire 220v circuits. Every home I've lived in, so far,
has been built before 1996. As time goes by, codes become more and more
stringent, sometimes benefiting the end user, sometimes just the
contractor/manufacturer. But, I can definitely appreciate grounding a
steel cabinet to a home's ground.


Ground and neutral are bonded at the service entrance so no need to waste extra copper on a 4-wire circuit.