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 load center.
Depends on the screw lug. Some are rated for two wires. Most aren't. Wouldn't hurt to check yours, though: you might be lucky.
I know of nothing in the NEC that would prohibit this.
I have a number of "2-wire/fuse" circuts Usually we don't run both of those machines at the same time.
My understanding is it's OK as long as there's adequate space for the splice in the enclosure.
Do those exist for 208V 3phase?
On Mon, 15 Oct 2007 10:19:03 GMT, firstname.lastname@example.org (Doug Miller) wrote:
Whoops....missed that part...sorry...mea culpa
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 available...
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 excitement ensues.
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 >>--
On Mon, 15 Oct 2007 10:46:03 -0700, Bruce L. Bergman
Much Magic Smoke is released as well.
"B Leg" = Boom Leg if pulling 120vts out of the panel
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 >>--
Code cite, please?
Perhaps because it's not prohibited by the Code?
Doug Miller wrote:
It could be construed to fall under the catch all neat workman like manner requirement if an inspector wanted to.
Only if sloppily made.
Doug Miller wrote:
A few splices in the load center certainly wouldn't be an issue, but with say a few dozen it would be quite difficult to make neat.
Well, perhaps... but the OP wasn't talking about making a few dozen.
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 inspector. ;-)
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 >>--
"Bruce L. Bergman" wrote:
I wouldn't bother. The catch all is good enough.
I always install a decent sized pull box (like 12x12x6) up high where all the existing runs will reach, and extend down from there to the panel through conduit. Makes things pretty neat.
Like I said, move to a different city or state...
Yep, and you can be sure you'll be hassled on your next project / job in that jurisdiction.
Easy way out is always easiest...
Anything goes once the inspection is signed off on.