Is there any reason that a generator and commercial power cannot share
a common ground?
I am thinking of installing a select duplex outlet as follows: 1.
Isolate the 2 outlets by removing the hot and neutral jumpers. 2.
Connect commercial power to one of the outlets and a generator circuit
to the other outlet. 3. However the ground is common to both outlets
and cannot be separated. So is there any reason other than purely
theoritical that the ground wire of both romex runs cannot be connected
at the outlet?
If done at an ng furnace, during an outage power could be applied to
the thermostat, igniter, and blower simply by moving a plug from one
outlet to another. Am I missing anything?
Yes they can if done correctly. Your generator is PROBABLY grounded
internally to establish the neutral, grounded conductor. This meets OSHA.
If you do not break this connection then you have a dual/multiple ground
which is prohibited by the NEC. 2 places that have a ground potential. Let
us not get into "supplemental grounding"'
Find someone locally that can help with the installation. If this is a
convince thing then your better off with an extension cord.
Personally I would not like the idea of half an outlet being dead at any one
time. Lots of folks make mini transfer switches that are a whole lot easier
for everyone to understand.
What is the guy that buys your home going to think of your proposed idea?
There was a discussion last week about damaging equipment connected to cheap
generators, so make sure you buy a good one and have an electrician check
everything. It's against code to have a furnace plugged into an outlet.
It's going to cause less grief to install two completely separate
boxes with their own receptacles for this.
Our electrical code would have a serious conniption fit over two independent
power feeds to the same receptacle box.
Another poster suggested that it was code-illegal to connect a furnace
by an outlet. I don't think ours prohibits it. Even if yours does,
I _believe_ that provided you didn't try to share the receptacle box
between the two feeds and otherwise did it right, an inspector would
likely grant you an exception since this is for a specific purpose:
[I'm not entirely up to date on generator connects w.r.t. grounding
interconnects to the rest of your system, so that's something you're
going to have to research. Generally speaking, by powering the furnace
this way, the ductwork will be grounded thru the generator. I believe
that implies you have to bond the generator's ground to the house
Chris Lewis, Una confibula non set est
It\'s not just anyone who gets a Starship Cruiser class named after them.
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