[Amps] Safety grounding - was Mains Isolation Transformer

[Tony King - W4ZT]

Gudguyham at aol.com wrote:
>  
<snip>...
> 
>   IF..that 
> device did not require 120 volts then the plug  configuration would not fit your 
> Honda plug.  The 4th wire of course is a  bond which does not carry current 
> unless a fault occurs.   Lou

Lou, that wouldn't necessarily be true.  If you had a 240 Volt device
that didn't have any 120 Volt needs at all, you would still HAVE to use
that plug to get the power from the generator.  In that case, two
conductors would have zero current. You either put the correct 4 pin
plug on your three wire cord or make an adapter.

There are hundreds of thousands of 3 wire 240 Volt receptacles in use in
the USA today that are still legal until someone makes a wiring change
that requires an upgrade to meet code.  Code changes don't mean that
existing wiring is illegal or unsafe. The change in code was to strictly
meet the need for handling both 240 Volt and 120 Volt loads from a
single receptacle and still provide the bonded safety ground. It has
nothing to do with what we really CAN do both safely and legally. Even
if you have a 4 wire receptacle, you can still use only 3 of them if
your load doesn't need the neutral for a 120 Volt current path. Leave it
off the plug or don't connect it in the device, it's all the same.

73, Tony W4ZT