Electrical – 200 Amp Service upgrade Failed Inspection NJ

electrical-panel

Im a Licensed Contractor and very comfortable with working on electric. That being said, my new home had underground 200 amp service and we could not disconnect the power so I used a licensed electrician to replace the exterior meter box that had rotted and install a new D Square 200 amp QO box (so I didn't have to work with the live 200 amp wires..). I thought he did a fantastic job looked clean and functioned great. Inspector came and Failed it, part one was for not replacing a piece of sheetrock next to the box (I left it off so he could see everything… Easy fix thought). The second Part stated "Multi Wire Circuits 2P CB on a approved tie Bar". I have no idea WTF this means lol. I wire outlets/lights and occasionally add a breaker for a new line. When I asked the inspector what this means he stated that the electrician would understand and it would take him 10 minutes to fix… My electrician bailed on me & won't return phone calls. I'd rather not call in a second electrician for something I'm sure I can fix myself. If anyone has any insight, please let me know.

Side note: All my wires in my house are BX with the exception of one is Romex added years later. My box does not have a separate ground bar in the box instead he tied the neutrals into the left side of the box and tied the grounds into the right. I was thinking the inspector wants a separate ground bar in the box the BX neutrals are fine on the left and the 1 Romex wire he wants that neutral on the Right. I

Breaking down what the Inspector said "Multi Wire Circuits 2P CB on a approved tie Bar" I presume means Multiple wire circuits 2 Pole on Circuit Breaker on approved tie bar? I just don't know what this means needs to happen to fix the problem lol

Thanks in in advance hope I explained this well enough.

Daniel

Best Answer

Heres my guess. It's an easy one indeed. By "multi wire circuit" he actually means multi-wire branch circuit. This is a special method of running 120V circuits where you get 2 circuits' worth of power on one /3 cable, by sharing neutral. You can google it, but the highlights inspectionwise are

  • the circuit must have neutral pigtailed, you can't use a receptacle etc. as a splice point for the onward neutral or you'd knock out both sides of the circuit if you removed the device.
  • Both legs must, must, must be on opposite poles.
  • both legs of the MWBC must have common maintenance shut-off, so the usual technique of "turn breakers off until the radio stops playing" turns off the whole circuit.

That last one is what you are being written up for.

In a residential breaker panel (as opposed to fuses or industrial), you do that one of two ways. You use a 2-pole breaker (like you would for a water heater, but the correct amperage)... Or you use listed "handle ties" that are correct for that breaker type. These are weird and specialty, and big-box rarely carries them. Sourcing them is such a hassle that I just advise people to use 2-pole breakers, which are sold everywhere for $10. This also leads them into correct decision making when selecting AFCI or GFCI breakers later.

Where

So you need to search your panel for circuits which have 3 conductors, not including ground: two hots and a neutral. In a panel like yours with all cables, the dead giveaway is a red wire for the second hot.

Follow each of them, and make sure every one lands on a 2-pole breaker. If you find a pair going to two singles, measure the voltage at the breaker between the two "hots". It had better be 240V. If it's not, congrats, you just dodged a house fire. Move those two "hots" to a 2-pole breaker of same amp rating.

The reason I advise 2-pole breakers in your case (besides the annoyance of finding listed handle ties) is that way, you don't even need to chase it to figure out if it's an MWBC. 2-pole breaker, done...

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