My load center is full but I need to add one more circuit (3 phase,
208Y, US code). I know I'm not supposed to put two wires in one screw
clamp, but can I use a short wire and a wire nut to connect two
circuits to one circuit breaker? I know I can do this outside the
load center in a junction box, but because the conduits are going in
the opposite direction, I would like to put the wire nuts inside the
On Mon, 15 Oct 2007, email@example.com (Doug Miller) wrote:
Well, they do exist for the 120V circuits (duplex) and 120/240V 1Ph
circuits (triplex or quad) that tap off from the 3-phase panel, so you
put duplex breakers in the other slots to make a 3-phase space
If it's true 120/208 you can put the doubles in any slot PROVIDING
you don't go over 42 poles total in the panel. For those of you with
a 240V 3-Ph Open Delta "High Leg" service you have to be REALLY
careful to only put 240V loads on the High Leg phase, or much
Look for the notches in the buss stabs (on a modern "Industrial
Interchange" panel - SqD Homeline, Murray/Siemens, Challenger) the
ones with a notch can take doubles and you might have to shuffle
circuits to put the 3-Ph breakers on the blocked stabs.
You can put doubles on the solid stabs, but you have to pay more for
the "Non-CTL" version breaker. (Can't get around that '42-poles in a
panel' rule unless you can claim it as a switchboard, 10% or less of
the circuits are lighting and convenience receptacle loads.)
--<< Bruce >>--
You are not /supposed/ to use the load center as a splice box - but
people do it all the time. I haven't run into an inspector yet
that's actually anal enough to call you on it for only one or two.
Now if there were thirty, someone was extremely lazy in the past and
(if you can find them) deserves to be shot. ;-) Time to rip it out
and redesign with a splice box outboard of the load center.
--<< Bruce >>--
It's in the NEC somewhere, no using the panel as a junction box.
You gonna make me go out, get the book, and look it up? ;-)
I always get worried they're going to call me on that one for a
panel change, where I had to extend half the wires so as to not
re-rope every home-run in the building.
The Inspector is Always Right If he decides not to concede the
point through a friendly discussion at the jobsite, resign yourself to
going through a lot of time and trouble to prove otherwise.
One: You get the code book out and you have the inspector walk you
through the section he cites and prove it's a violation. Of course,
you have already done the research and can prove that what he is
complaining about is wrong, has an exception elsewhere in the book, or
is simply not applicable. And if he still doesn't back down you have
to escalate it to his supervisor, and you can write off a few days of
your productive time hassling over stupid shit.
Two: If the hold-up infraction can be "fixed" quick and easy you fix
it, get the stupid job signed off, and get paid...
And if you know in your heart that the Inspector was way in the
wrong, to the point where the change made it less safe, you can put
the item back the way you think it should be - since that piece of
gear will most likely never be inspected again for many years (if
ever), and unless it's a really small town certainly not by the same
Where it gets to be a nightmare is when you get two inspectors from
different divisions fighting over how a certain item is to be done -
the Plumbing Inspector tells you to rip it out and change it to his
way, and the Electrical Inspector sees the change you made to get the
Rough signed off and tells you to change it back...
--<< Bruce >>--
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