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I installed a Siemens QT (2) two pole quadbreaker into my panel board. All 4 circuits go to the same location. The inner two breakers and outer two breakers are common trip. However due to my setup I would like all 4 breakers to trip if any single circuit breaks. I know they have tie down bars but cannot find one for a quadbreaker. Not to mention I will have to cut the existing common trip bars off. Is this safe and is there a correct way to do this. People on reddit told me to use a nail stuck through them all. However I don't think nails are UL listed ;) Below is an image of the exact breaker I used. Any input?

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  • Just what the heck are you feeding with this weird setup? – ThreePhaseEel Dec 27 '16 at 23:16
  • Also, do you have spare slots in this panel to play with, or are you running out of slots already? – ThreePhaseEel Dec 27 '16 at 23:17
  • I am out of spots in the breaker box. Also because of the need for phase cancellation on a shared neutral on a MWBC I was forced to use a quad breaker. There is a tandem breaker on the other side of the box that has one side not being used. So I guess there is a spare spot... – Dylan Dec 28 '16 at 0:37
  • I am feeding large power tools, ventilation, A/C, space heaters, fans and many other things I am forgetting to mention – Dylan Dec 28 '16 at 0:44
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    Sheesh -- sounds like you should put a subpanel in instead of having all this crap dangled off a single quadruplex breaker! – ThreePhaseEel Dec 28 '16 at 1:16
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Don't improvise.

A breaker is a combination of an overcurrent detector and a switch, with a motor mechanism which causes one to throw the other. The motor mechanism is passive; it is a spring.

Each single breaker has enough motive power to throw its own switch, and also its partner switch.

It does not necessarily have enough motive power to throw four. You could have a horrible situation where none of the breakers trip because the other 3 are preventing the first's mechanism from operating.

You should not improvise such a thing. Contact the manufacturer for advice.

Can you live with three?

They may make 3-phase breakers for your style of panel. Obviously they are designed for phase A-B-C, but they will work fine with phase A-B-A which is what would happen if you put that breaker in a 120/240 split phase panel. Don't share the neutral!

They will not be duplex/double-stuff breakers, however.

  • The comment about the single breaker not having enough motive power to throw the other 3 is a great point I had never even considered. I knew I was smart to ask you guys. Unfortunately I need 4 circuits. But I will contact Siemens like you recommended and see if they have any recommendations. Out of curiosity why then do they sell tie bars for breakers given this information? – Dylan Dec 27 '16 at 23:52
  • Try it. You'll probably find the listed handle-ties are designed so they can't stack. – Harper Dec 28 '16 at 0:09
  • If one circuit is auxiliary (Not likely to be the one that initiates the trip), it can be fed through a relay powered by one of the other three. – Harper Dec 28 '16 at 0:11
  • Oh no I don't want to try it. You are right it doesn't seem wise. What do you mean it can be fed through a relay? I was maybe going to try to figure out something "post-outlet" to turn everything off if something fails. Basically I have 4 circuits. Circuit 1,2 and 3 do all the work and generate all the heat. Circuit 4 handles cooling. If 1,2 or 3 fails I would prefer that everything else keep running. However if 4 trips I want the rest to turn off. Are they devices for this? – Dylan Dec 28 '16 at 0:16
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    @Dylan -- a-ha. It sounds like you don't want all four trips commoned together after all, but an alarm contact + a shunt trip that causes the cooling zonking out to trip out the rest of the stuff. (Maybe we can find a way to wedge a temp sensor in as well, so in case the cooling mechanically dies but doesn't trip the breaker, the rest of the stuff will get depowered before crap gets super-stuffy) – ThreePhaseEel Dec 28 '16 at 1:19

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