What do you think is this ok?

Andy Jarchow · 01-29-2011, 08:25 PM

Hello all,

A friend of mine asked me an electrical question. I told him I didn’t think this would cause any problems but would like to get advice from an electrical expert…

This is what they did. They wired a bedroom with 3 wires and a ground - one hot, two grounded conductors (neutrals).

The lights are wired with one (white) grounded conductor and the receptacles are wired with the other (white) grounded conductor. The lights and the receptacles share the same hot and ground.

Your feed back is appreciated.

Thank you all!

**Jerry Peck** · 01-29-2011, 08:49 PM

You've got a mis-wired multiwire circuit, one which could burn up the hot conductor, and possibly even the grounded conductors, along with other possible bad tings.

They could, however, re-wire those so that the two parts of the circuit were served by two different HOT conductors and served by ONE grounded conductor ... AS LONG AS the two different hot conductors were on the two different bus bars.

That makes for two 120 volt circuits (with 240 volts between the hot conductors) sharing one neutral, and only the unbalanced current is carried by the neutral. Wired with the two 120 volt circuits on the same bus (120 volts between the hot conductors) and the neutral will carry TWICE the current as the current through each hot adds together on the one neutral - they did this last thing in reverse, carrying the current from BOTH circuits on the one hot conductor.

They NEED to call an electrician ... AND NOT USE that circuit in the meantime.

Andy Jarchow · 01-29-2011, 09:04 PM

Originally Posted by Jerry Peck

You've got a mis-wired multiwire circuit, one which could burn up the hot conductor, and possibly even the grounded conductors, along with other possible bad tings.

They could, however, re-wire those so that the two parts of the circuit were served by two different HOT conductors and served by ONE grounded conductor ... AS LONG AS the two different hot conductors were on the two different bus bars.

That makes for two 120 volt circuits (with 240 volts between the hot conductors) sharing one neutral, and only the unbalanced current is carried by the neutral. Wired with the two 120 volt circuits on the same bus (120 volts between the hot conductors) and the neutral will carry TWICE the current as the current through each hot adds together on the one neutral - they did this last thing in reverse, carrying the current from BOTH circuits on the one hot conductor.

They NEED to call an electrician ... AND NOT USE that circuit in the meantime.

Hi Jerry,
I believe they wired this on one circuit. The neutrals & ground go to the bus bar and the hot ties into the 120 v circuit. Is this how you understood it?

**Gunnar Alquist** · 01-29-2011, 11:01 PM

Originally Posted by Jerry Peck

You've got a mis-wired multiwire circuit, one which could burn up the hot conductor, and possibly even the grounded conductors, along with other possible bad tings.

Jerry, I don't get this part. One hot (nongrounded) and two grounded conductors. This is not a miswired multiwire circuit (two hots are needed for that). Assuming the hot is properly sized to the OCPD, how could splitting the neutral between two conductors cause problems?

James Duffin · 01-30-2011, 06:49 AM

I'm wondering where they found a cable with a black, two whites, and a bare wire?

**Jim Port** · 01-30-2011, 07:09 AM

This is only one circuit as the OP stated one hot and two neutrals. There will not be anymore chance of overload than with any other circuit. The issue is that the neutral is paralleled. Conductors sized for a typical branch circuit are way too small to be paralleled according to the NEC.

**Jerry Peck** · 01-30-2011, 08:08 AM

Originally Posted by Mike Krueger

Hi Jerry,
I believe they wired this on one circuit. The neutrals & ground go to the bus bar and the hot ties into the 120 v circuit. Is this how you understood it?

"Is this how you understood it?"

No, I was taking it as they somehow were feeding it from two circuits with the conductors being the wrong color, i.e., a mis-wired multiwire circuit.

Now the problem is confusing me even more:
- There is one black conductor which runs through the entire circuit - to the lights and the receptacles, along with a ground.
- There are two white conductors which run as follows: one runs to the lights and one runs to the receptacles.

James Duffin asked "I'm wondering where they found a cable with a black, two whites, and a bare wire?"

I'm wondering the same thing too.

Jim Port said "The issue is that the neutral is paralleled."

That would be an issue if they were paralleled, and you said "The neutrals ... " which tells me that the neutrals are paralleled back to the panel for the reason Jim gave.

You also said "The neutrals & ground ... ", which indicates only one ground is going back to the panel. This indicates the hot and the ground go from the panel and around the entire circuit, but the neutrals are split?

Is that system in conduit or cable?

Andy Jarchow · 01-30-2011, 10:32 AM

Thank you all for your time and info so far.

I didn't see what he had I'm going by what he told me. I will call him and get some specific details...

Thanks again I appreciate the advice!

Guy W Opie · 01-31-2011, 05:11 AM

I do not know why anyone would wire a circuit this way. Since, I have never seen wire with 1 black , 2 whites and a ground, tan one of the wire had to be taped white. That is a violation of the NEC. I would rewire the circuit as true multibranch.

**Jim Robinson** · 01-31-2011, 08:40 AM

It might be simpler just to not use one of the neutrals.

**Mike Locurcio** · 01-31-2011, 09:18 AM

The wiring method is unorthodox, but not wrong in any way. I would just do a load calculation and determine if there were too many points on the circuit and call it a day.

Andy Jarchow · 01-31-2011, 09:22 AM

Originally Posted by Mike Locurcio

The wiring method is unorthodox, but not wrong in any way. I would just do a load calculation and determine if there were too many points on the circuit and call it a day.

I don't think the load would be an issue. It's only a bedroom with two lights and 3 or 4 receptacles...

I didn't hear back from him yet on the details. I left him a phone message yesterday.

Thanks all!
Have a great day!
mk

**Jerry Peck** · 01-31-2011, 05:21 PM

Originally Posted by Jim Robinson

It might be simpler just to not use one of the neutrals.

Not as easily done is wired as I am now visualizing what he described - that there are two neutrals going out from the panel, which indicates that the are not going the same place, which means that one of them does not have a hot wire running with it (this is not allowed) nor does it have a ground running with it (not allowed either).

Now, if the neutrals were paralleled the entire way and one just continued out to the next items ... then, yes, one neutral could be abandoned, but why would it have been installed in the first place.

Which is why I suspect one neutral is running somewhere by itself.

**Jim Robinson** · 01-31-2011, 05:29 PM

The lights are wired with one (white) grounded conductor and the receptacles are wired with the other (white) grounded conductor. The lights and the receptacles share the same hot and ground.

Okay, I read it again. One neutral to the lights, one to the receptacles. As long as they both terminate at the neutral bar, it shouldn't change anything. Why'd they do it? Who knows? If they both pass through each box, you could eliminate one of them, but we don't know if they do that or not.