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Andrew Erickson Andrew Erickson is offline
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Default 220 V table saws and ground

In article ,
dpb wrote:

Leon wrote:
...
Hey It is hard to tell what the voltage is any more. LOL. 2 weeks ago
"after" having 3 new leads run underground to my home, I lost electricity
in
1/2 of my house and had no 240? ;!) I started having issues with lights
diming.


Bad neutral is different that my reference altho can be entertaining set
of symptoms (unfortunately, which may also turn into expensive)...


Loss of one hot at the breaker panel can also be entertaining, although
generally not as destructive. I've had that happen once or twice,
mainly at a house with an older distribution panel that used individual
cartridge fuses for the main rather than a ganged circuit breaker. Have
one wear out or go pop or whatever, and suddenly you have one phase
powered normally, and one phase powered through any 220V things that
happen to be on--mainly the water heater, in my case. Small loads
worked fine on that leg, but anything that drew any current would cause
the voltage to go down dramatically. The microwave clock, for instance,
ran fine, until actual cooking was attempted....

...

BTW, on that 240V circuit, I'd presume it is more than likely ok but it
might not hurt to double check did actually hook the ground conductor to
the ground buss in the box rather than to the neutral buss if really
were thinking neutral as opposed to ground way back then...nothing is
going to happen but it really ought to be on ground, not neutral per Code.


It depends where you're talking about checking. There is one point in
the system, typically at the main disconnect (the main breaker box),
where neutral and ground are bonded together, and at that point the
neutral buss is the ground buss and vice-versa.

For separate outbuildings, I think (but I'm not sure about this, not
being an electrician) the usual practice is to have a separate ground
rod and bond that to the neutral bus at the outbuilding's main panel,
omitting a separate safety ground wire between the buildings. In other
words, the outbuilding is wired as though it were an isolated
installation, not as a subpanel in the main building. In this case, for
the main panel in the outbuilding, neutral and ground would again share
the same bus bar(s). Any difference in ground potential between the
house ground and the outbuilding ground would, of course, result in a
current flow over the neutral wire; the assumption, I guess, is that
there shouldn't be a large potential difference and hence not too great
of a current flow.

--
Andrew Erickson

"He is no fool who gives what he cannot keep to gain that which he cannot
lose." -- Jim Elliot