wiring a 120 v breaker panel - NEC issues


Old 08-14-04, 11:25 PM
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Red face wiring a 120 v breaker panel - NEC issues

I am wiring a 120/240 v breaker panel which is fed by a 120 v line from an inverter. Since there is only one hot wire (black), and two "hot" legs on the breaker panel, I have to somehow connect the same black wire to both legs so that all breakers will connect to it. According to NEC code, can I have the black wire go to one leg and also connect a piece of black wire under the same screw terminal which will then go to the screw terminal of the other leg of the panel? Does the NEC code have a problem with putting two #6 wires under the same screw terminal?
Since this line is passing through a junction box before entering the breaker box, I could split the black line there and bring two black wires into the breaker box and have only one wire under each screw terminal. Is that better according to the NEC code? Also I'm planning to have the bottom of the breaker box be about 5 feet 2 inches above the basement floor. Is that OK?
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Old 08-15-04, 12:03 AM
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Do you need all the breaker spaces? I'm thinking you could just leave one leg unconnected. Seems like you probably don't have enough power to use both sides anyway.
Old 08-15-04, 11:07 AM
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Thanks for such a prompt response

Yes, I do need all the breaker spaces. As it is I'm using QOT1515 double (half size) breakers.
Old 08-15-04, 11:52 AM
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If you are connecting to a main breaker no!, if you are connectig to a set screw lug it depends on if it is ul rated for more than one wire. this can be found on the door of the panel.
Old 08-16-04, 10:35 AM
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"If it's not there, it can't fail"---- this would apply to connecting 2 wire-leads to the Feeder conductor at some point.

Expose approx. 2" of the #6 conductor approx 6" from the end of the conductor-----make a "U-bend" in the center of the exposed section and crimp the U-bend together with side-cutting pliers so the U-bend "resembles" a single,larger conductor, and insert this "conductor" into the lug-opening.

This solution presumes the lug-opening will accomodate the "synthetic" conductor. You can "experiment" with a piece of #6 conductor. You will note that there are no 'breaks" in the conductor.

Goood Luck & Enjoy the Experience!!!
Old 08-16-04, 11:11 AM
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Sorry to disagree with you Pattba, but I see several problems with your unbroken single conductor. First would be the violation of the bend radius on the conductor. Secondly while it would only be one physical conductor I would seem to think that this would still be a violation of the single conductor per terminal based on the intent of that listing.
Old 08-16-04, 03:38 PM
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"I see several problems---- one--- two---- ? ? ? ? ?"

Art 300.34, Conductor Bending Radius--- This Art is in Sec II, Requirements for over 600 volts.
Old 08-16-04, 04:07 PM
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You could use a split bolt connector. Primary feed comes in, extra long section of exposed conductor so you have room to attach the split bolt and second conductor. You only have 1 conductor under each lug and bending radius isn't an issue. I've seen these for sale at Home Depot.

Here's one example: ILSCO Al/Cu-rated Split Bolt Connector

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