[AT] : Ice Storm

[Mattias Kessén]

Henry? Am I right in assuming then that in the USA every house/electrical
has it's own grounding point opposite to how it works here. Because here
you got to have a switch that disconnects your own electrical system from
the net when connecting a generator. Since we have ground in the net I then
have to have my own groundingpoint (All that copper in the cround).

John If the depth are enough depends on the kind of ground you got. There
are a lot of complex measuring to decide that.

Though I have a lot knowledge about this but not being an electrician(My dad
is, I've actually worked as one :-o, and I've got a bunch of education to my
teflon-brain). I will not try to understand or explain the floating neutral
potential phenomenon (or something like that) that an electrician friend of
mine tried to explain to me. Anyway this has made electrical macinery like
fridges overheat and burning down houses here so be careful.

/Mattias


2007/12/15, Henry Miller <hank at millerfarm.com>:
>
> On Friday 14 December 2007 12:45:15 charlie hill wrote:
> > Mike you are probably 90% ok since you are grounded through the transfer
> > switch.  I was primarily talking about the units that are sitting on
> > trailers and connected via drop cords.  If you plug something into the
> drop
> > cord in that application  you have no ground.
> >
> > I'm not qualified to talk about your situation because I'm not an
> > electrician by any means BUT my friend said something about a ground
> > potential difference between the ground in the house and the generator
> unit
> > and said that the unit it's self should be grounded.  Maybe someone else
> > can explain that.  Like I said, I don't really know other than what I
> was
> > told. Electrical stuff is one of my very weak points.
>
> Grounds are VERY complex.   They seem simple, but they are the most
> complex,
> most dangerous part of an electrical system.
>
> Summery for those who don't want to know the whys:  When using a generator
> as
> portable power, plug into a GFCI outlet and ignore the ground connections
> (if
> your generators doesn't have a GFCI get one installed).   When using a
> generator to power your house, the house provides the ground, any earth
> connection at the generator could be a DEADLY second ground!
>
> Long explanation follows:
>
> The safest system has NO ground connection at all, and perfect wiring.
> If
> there is no ground connection you can safely grab a live
> wire.  Unfortunately
> things are not that simple, it only takes one mouse (every house has mice)
> in
> the walls to turn your perfect wiring into wires with problems.   One
> problem
> isn't too big a deal, as you shouldn't be touching the wires
> anyway.    When
> there is a second problem it can burn your house down!  Fuses won't
> protect
> you because these problems don't have to be big enough to blow a fuse to
> burn
> the house down.    So fire code requires (and rightly so) that one wire
> has a
> good connection direct to ground.  The hope (and this mostly works out) is
> that if there is a problem, the good ground will make it more likely that
> a
> fuse will blow.   There are many different cases of a bad ground and
> several
> electrical problems burning a house down, so make sure your house has a
> good
> ground.
>
> Note that I said A good ground, as in singular!   Strangely enough, two
> grounds can kill you just by walking in the wrong place.   (Sometimes a
> house
> will have several different ground rods, but these are carefully connected
> so
> they act as one ground)  So if your have your generator wired to a
> transfer
> switch in your house you should not have a ground connection on the
> generator, as your house is already grounded.   If your generator has a
> ground point (and all non-plastic generators should), it should be
> connected
> not to the earth, but to the ground connection in the house.   (By rights
> your generator should have a switch so you can select if generator is
> grounded at the house or in the generator, but I've never seen a generator
> with this, most likely because the switch wouldn't be connected right
> anyway.)
>
> For generators on a trailer (meaning not used to power a house) the
> situation
> is different.   The rules are simple: Grounds are for fire protection, and
> not human protection.  GFCIs are for human protection.   So for your
> outdoor
> use make sure you only plug things into GFCI outlets (Don't forget to test
> all GFCIs monthly by hitting the test button and making sure all outlets
> you
> think should be protected really turned off).   The GFCI will take care of
> everything you want a ground for, and avoid the hassle of getting a good
> ground connection.
>
> If you can't use a GFCI outlet, double insulated tools and good cords
> (inspect
> them as you unroll them, and get rid of any that are getting frayed) are
> good
> enough.  Equipment that has a ground connection is a risk when run from a
> generator.
>
> Note, if you have a pacemaker things are more complex yet, because they
> are
> affected by tiny currents that you wouldn't notice.   I recommend you
> check
> with your doctor and pacemaker manufacture to see what the rules are,
> before
> you use any generator or welder.
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