Hi all,

Looking for some help here.
The photos below are of a service panel in a single family dwelling located in NYC.

Photo 1
Photo 2
Photo 3
Photo 4

The house was built in the 70's and the panel was replaced around 2005 by an "electrician" (I'm being sarcastic because this does not look like the work of a licensed electrician).

The breakers used appear to be replacement breakers, yet this is a CTL assembly. There is also a neutral wire coming off a 240 volt central air conditioning unit which was never reconnected (not sure if that's an issue, the unit has worked for years this way).

I also don't see any insulating bushings?
Also, the burn marks on the red 40 amp wire (central air unit) are from the previous breaker which was replaced. Vibration from an old garage door opener shook it loose over the years and was causing arching. I assume an electrician with a clue would have cut the damaged portion of that wire off.

I appreciate any help so we can have a real electrician properly fix this.

Thanks!

1) No main breaker hold down. Violation

2) Bushings not required with AC cable. No violation.

3) The white spliced wire is newer THHN wire. The ones I can see in Pic #4 are #12. The old is TW (much thicker insulation). It could be #14 but is impossible to tell from here. Probably no violation.

4) I see at least two multi-wire circuit going to the same twin breaker. VIOLATION!

5) Central AC would not typically require a neutral. No violation.

6) The burned wire on that 40 should definitely have been cut back. VERY poor workmanship.

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Originally Posted by stanfortyman

1) No main breaker hold down. Violation

2) Bushings not required with AC cable. No violation.

3) The white spliced wire is newer THHN wire. The ones I can see in Pic #4 are #12. The old is TW (much thicker insulation). It could be #14 but is impossible to tell from here. Probably no violation.

4) I see at least two multi-wire circuit going to the same twin breaker. VIOLATION!

5) Central AC would not typically require a neutral. No violation.

6) The burned wire on that 40 should definitely have been cut back. VERY poor workmanship.

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Thanks for your help.

About #4 - you mean multiple wires going to the same hold down on a single breaker, right? It just looks that way from the photo. Each breaker only has 1 wire.

No, a multi-wire circuit is where a black and red share a neutral. In this case the black and red MUST be on different legs of the panel. I see two spots where the black and red are both going to the same twin breaker.

Also, I thought bushings were required with AC and not MC?

Quote:

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Originally Posted by stanfortyman

No, a multi-wire circuit is where a black and red share a neutral. In this case the black and red MUST be on different legs of the panel. I see two spots where the black and red are both going to the same twin breaker.

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Gotcha. Only because I'm interested in this sort of thing (thinking of becoming an electrician at some point) would you mind explaining that to me in more detail? Thanks!

There are 5 twin breakers in total with a black and a red going to them (all of the breakers along the right side except the top one which isn't connected).

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Originally Posted by GLink

Gotcha. Only because I'm interested in this sort of thing (thinking of becoming an electrician at some point) would you mind explaining that to me in more detail? Thanks!!

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With a multi-wire circuit the black and red share a neutral. The neutral in this case only carries the amperage imbalance of the two circuits. Similar to a straight 240v circuit which requires NO neutral because there is no imbalance between the two hots.

If the black is carrying 10 amps and the red is carrying 7 amps the neutral is only seeing three amps.

Now, if the two hots are sharing the same leg in the panel the neutral will see the combination of the two loads. So in the above scenario the neutral would be seeing 17 amps instead of three.
Think about this if you had two legs carrying 16 amps each on a 20A circuit. The #12 neutral would be seeing 32 amps. Not a good thing.

Quote:

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Originally Posted by stanfortyman

With a multi-wire circuit the black and red share a neutral. The neutral in this case only carries the amperage imbalance of the two circuits. Similar to a straight 240v circuit which requires NO neutral because there is no imbalance between the two hots.

If the black is carrying 10 amps and the red is carrying 7 amps the neutral is only seeing three amps.

Now, if the two hots are sharing the same leg in the panel the neutral will see the combination of the two loads. So in the above scenario the neutral would be seeing 17 amps instead of three.
Think about this if you had two legs carrying 16 amps each on a 20A circuit. The #12 neutral would be seeing 32 amps. Not a good thing.

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Wow. Not good. So basically, if I load up 2 of those circuits just below the limit of the breakers and they're sharing 1 neutral, I'm going to melt the wire / possibly start a fire?

Also I just checked, all of the wires (with the obvious exceptions) are 12 AWG and the wires they used to extend the neutrals are 14 AWG - that also sounds like a violation to me.

Quote:

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Originally Posted by GLink

Also I just checked, all of the wires (with the obvious exceptions) are 12 AWG and the wires they used to extend the neutrals are 14 AWG - that also sounds like a violation to me.

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It is, but are you sure?

In Pic #4 I can clearly see a new THHN stranded that says "AWG 12", just to the left of your red arrow. This is one of the new wires he used to extend the neutral.

Quote:

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Originally Posted by stanfortyman

It is, but are you sure?

In Pic #4 I can clearly see a new THHN stranded that says "AWG 12", just to the left of your red arrow. This is one of the new wires he used to extend the neutral.

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Sorry you are correct, I just double checked they are indeed all 12 AWG.
I guess the thinner insulation threw me off; that and I think the heat is getting to me today!

I just read up on multi-wired branch circuits and split-wired receptacles and now I have another concern, but it does not make much sense to me. Years ago we had all of the old 1970's outlets and switches replaced with newer ones. I watched the person who did it and never saw any tabs removed for split-wired receptacles. So that would mean both legs were attached to the receptacles and combined, but that makes no sense to me because (I think?) you would be combining both phases, creating basically a short, which would have either thrown the breaker or burnt the place down! Obviously that never happened... so now I'm wondering if / how the outlets could also be mis-wired?

Before anyone says it, yes I realize this is a job for an electrician and not something to tinker around with.

Quote:

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Originally Posted by GLink

Sorry you are correct, I just double checked they are indeed all 12 AWG.
I guess the thinner insulation threw me off; that and I think the heat is getting to me today!

I just read up on multi-wired branch circuits and split-wired receptacles and now I have another concern, but it does not make much sense to me. Years ago we had all of the old 1970's outlets and switches replaced with newer ones. I watched the person who did it and never saw any tabs removed for split-wired receptacles. So that would mean both legs were attached to the receptacles and combined, but that makes no sense to me because (I think?) you would be combining both phases, creating basically a short, which would have either thrown the breaker or burnt the place down! Obviously that never happened... so now I'm wondering if / how the outlets could also be mis-wired?

Before anyone says it, yes I realize this is a job for an electrician and not something to tinker around with.

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Unless of course the original breaker box was miswired the same way the new one is, then you wouldn't be combining different phases, but definitely creating a huge fire hazard...

All of Stan's points are dead on.

Get those tandem breakers rewired, soon.

The spare neutral needs to be terminated or capped.

Poor workmanship is a code violation.

DIY'ers, hope your listening.

What is your interpretation of this:

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The breakers used appear to be replacement breakers, yet this is a CTL assembly.

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Best case would be that it is a Murray panel ,however there are several brands that are compatible with each other, Murray, Bryant, T&B, come to mind.

I believe you will find the UL listing of this panel fine with the breakers you have.

The tandems can be an issue, something that sneaks up, similar to high blood pressure, but this smokey.

Good point on the tabs on the outlets. If the breakers are rewired properly, and if the tabs are still on outlets intended to be split wired, each breaker will trip as soon as energized, and sparks will fly at some of those outlets, maybe more.

Something to check.

Who will be making the corrections?

If your thinking about being an electrician, click on the Sticky at the top of the forum to the National Electric Code. Take a breeze through it.


Do not try to learn by just reading this book, it is not a training tool.

Quote:

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Originally Posted by GLink

Before anyone says it, yes I realize this is a job for an electrician and not something to tinker around with.

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The fact that you are in NYC make this the law.

Thank you both for the help.

I will check with my multimeter to see if those circuits are isolated as they should be (tabs) by checking to make sure there is no continuity between the red / black wire in each circuit. That would be the correct way to test that as long as there are no appliances plugged into the outlets in question (as they could create a circuit between them). Correct?

I will not be making any changes myself. I have a friend who is a licensed electrician, hopefully I can get him to come and work for beer ;).

If tab on receptacle is intact, and it has a red and a black on each screw, it was probably the wire they had on hand, red would be from 1 direction, and black in from a different location. If the red and black come in on the same cable as the white. They might be protected by 2 breakers, turning either one off will not kill the circuit, and the reason it didn't trip, is because they are on the same phase?
May not be your situation.

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Originally Posted by Stratmando

If tab on recepticle is intact, and it has a red and a black on each screw, it was probably the wire they had on hand, red would be from 1 direction, and black in from a different location. If the red and black come in on the same cable as the white. They might be protected by 2 breakers, turning either one off will not kill the circuit, and the reason it didn't trip, is because they are on the same phase?
May not be your situation.

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I just checked that on one of the circuits in question. There is 1 cable with red,black, neutral. The red and the black from that cable both go to a separate breaker, however both breakers are on the SAME phase. I checked to see what each breaker controls. One of those breakers (red wire) goes to one outlet with its tab intact. The other breaker (black wire) goes to the outlet NEXT TO that one which has its tab intact (one outlet is meant for a washer, other for a dryer). Looking behind the outlet I see a whole bunch of neutral wires and a bunch of black wires (they used the outlet as a splice box basically). That really confuses me because I cannot find any other outlets or lights in the house controlled by either of those breakers. They appear to be only for the washer and dryer. I then turned both breakers off, unplugged anything in either of those outlets, and checked for continuity between the red and black wires with my multimeter. There was none, so they are not tied together, which would lead me in my totally unprofessional opinion to believe that it is wired in a way that is OK. Either way, going to have an electrician take a look because that is only 1 of the circuits in question.

Quote:

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Originally Posted by GLink

I just checked that on one of the circuits in question. There is 1 cable with red,black, neutral. The red and the black from that cable both go to a separate breaker, however both breakers are on the SAME phase. I checked to see what each breaker controls. One of those breakers (red wire) goes to one outlet with its tab intact. The other breaker (black wire) goes to the outlet NEXT TO that one which has its tab intact (one outlet is meant for a washer, other for a dryer). Looking behind the outlet I see a whole bunch of neutral wires and a bunch of black wires (they used the outlet as a splice box basically). That really confuses me because I cannot find any other outlets or lights in the house controlled by either of those breakers. They appear to be only for the washer and dryer. I then went ahead and turned both breakers off, unplugged anything in either of those outlets, and checked for continuity between the red and black wires with my multimeter. There was none, so they are not tied together, which would lead me in my totally unprofessional opinion to believe that it is wired in a way that is OK. Either way, going to have an electrician take a look because that is only 1 of the circuits in question.

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Sorry that last post was probably unclear (I wish there was an edit button). I meant to say that they are wired in a way that is OK, so an electrician could switch those wires to separate phases without having to worry about any shorts at the outlets.

If an Electrician hooks the 2 on opposite phases with the tab intact, 1 or both breakers will trip.
Easy way to verify, measure the voltage on the red and black in question, if you read 240 volts, you are on opposite phases, if you read zero volts, you are on same phase.

Quote:

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Originally Posted by Stratmando

If an Electrician hooks the 2 on opposite phases with the tab intact, 1 or both breakers will trip.
Easy way to verify, measure the voltage on the red and black in question, if you read 240 volts, you are on opposite phases, if you read zero volts, you are on same phase.

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Yep, already did that and marked the bad ones. What I meant though was to check the bad ones and find out if the tab is intact by checking to see the resistance between the red and black of the circuit(s) in question by turning off the breakers, unplugging any appliances, and then measuring by placing the leads of my multimeter on the red and black wires where they are screwed into the breakers. The resistance should be infinite (open circuit) if the tab has been removed. Otherwise I should be seeing merely the resistance of the wires, telling me that there is a circuit and the tab needs to be removed first. I just wanted to find out if this method of testing is acceptable.

I would plug something in top, then bottom of receptacle to verify with a load(or Wiggy)you have voltage.
Its like Water heaters, instead of removing wires from Element for testing, use an Amprobe and a Voltmeter, If you have voltage to Element and NO load, the Element IS open.
More work to open and measure resistance.

Back in the 70's the big thing was splitting the tab on the recept so that the top outlet was controlled by a switch for plugging in floor lamps and the bottom outlet was constant hot. Back then a lot of houses did not have ceiling lights. Most recepts were wired with a black/red/white wire with one color going to a switch. Maybe this will help to determine your situation

Like jerro was mentioning the red sometimes will be the switch leg, if they are separate to the panel, this may not be the case.
Switching half a receptacle is still done, sometimes on a 3 way, with other switch near the bed?