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I hear that shared-neutral or multi-wire branch circuits (MWBC) can have issues when used with tandem breakers (also called duplex, twin, cheater or double-stuff breakers). Do my breakers have a shared neutral?

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    I asked this because I am planning to relocate the 1 of the 15A breaker to a different panel. as far as I know is if the tandem breaker has a shared neutral, I will have to relocate both of them. so my breakers do have a shared neutral correct ? May 29, 2021 at 18:15

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Tandem breakers in the photo sharing a neutral is a code violation! But may not have been when installed. A quad or double tandem is the only one that can share a breaker if handle tied as the quad breaker bridges 2 poles.

With your current setup the neutral is not doubled as is common because at least the circuits were split, but they are not handle tied. And this has been code for a while.

My jurisdiction has required handle ties for ~20 years. I think the NEC has only required them for ~8 years so if your home is older there is nothing unsafe with the install with regard to overloading the neutral.

The issue with your configuration is if you turn off the top breaker to work on that circuit and the bottom circuit has a load you can get shocked from the neutral.

So you don’t have a fire hazard as is common with tandems but they don’t meet current code because of the lack of handle ties.

I do not know if there are ties for duplex to turn them into quads I have only done the center pair not the outer pair but I know quads are sold just not sure about a quad 15 with ties.

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    Simultaneous disconnect NEC 2008. Prior to that simultaneous disconnect was only required for shared yoke. May 29, 2021 at 16:04
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    Looks like 5 wires going into those two breakers. Do I need new glasses? +1
    – JACK
    May 29, 2021 at 16:48
  • Yes, they make 15/15 quads. Eaton even makes them with or without common trip! May 29, 2021 at 17:44
  • I asked this because I am planning to relocate the 1 of the 15A breaker to a different panel. as far as I know is if the tandem breaker has a shared neutral, I will have to relocate both of them. so my breakers do have a shared neutral correct ? May 29, 2021 at 18:14
  • Kaissa, yes if the circuit comes in on a 14-3 cable you need to relocate both the hots neutral and ground to the new panel. @nosparksplease thanks I knew it was more recently changed by the NEC but my state or possibly county as I moved a few years back and never noted if my changes were county or state. Harper is the common trip across all 4 breakers? I suggest subs to most home owners but have used quads a few times.
    – Ed Beal
    May 30, 2021 at 2:06

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