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What is the deal with Dual Breakers


Mark P

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I'm not sure if "Dual breaker" is the correct term, but it is a breaker with 2 individual single pole breakers in one

So a few years back someone bought this house 5500 sqft house and needed to upgrade the electrical service. The panel that was installed is not big enough for all the circuits so a number of these "dual breakers" were installed and even some of them are doubled taped. I understand that a larger panel should have been installed and the sparky wanted to save a few bucks by putting in this box and using dual breakers and double taps to make it all fit. I guess my question is are the dual breakers Kosher?

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Some municipalities (mine) limit the number of tandems to *2*. Other than that, there's nothing wrong w/them. They're UL listed.

They don't want panels getting too jammed up w/wiring, and the union wants the gravy of updating the panel.

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Manufacturers were supposed to design their panels and breakers so that the tandem/dual/half-sized/whatever breakers could only be installed in designated spots. The idea was to keep some knothead from getting more than intended maximum number of circuits out of a given size panel. Unfortunately almost all of the manufacturers failed miserably at doing that, so you might find a 40 circuit panel with 57 circuits in it. If so, it ain't right. Check the label against what's actually there (if you can see the label).

Brian G.

Knotheads Find a Way [:-dunce]

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Originally posted by AHIS

Originally posted by caryseidner

You mean "Kosher"...right?

Oh yeah that is what I meant. thanks

Tandem, tandem tandem - okay I think I've got it - tandem, tandem, tandem

Thanks also Kurt and Bain.

Also Known As: Piggyback Breakers

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Originally posted by kurt

Some municipalities (mine) limit the number of tandems to *2*. Other than that, there's nothing wrong w/them. They're UL listed.

They don't want panels getting too jammed up w/wiring, and the union wants the gravy of updating the panel.

Everytime the Unbelievable corruption in NJ starts getting under my skin, I just think about Chicago... It makes me feel better. A little.

There's a whole education to be had about "split" breakers as they are called around here. Not sure I can bear the carpal tunnel pain right now. As others have said, nothing wrong with the breakers, just in how they are used. Some panels are rated ???amp. 30/30 (30 slots/30 circuits max.) (no splits, tandems, piggybacks allowed). Others may be rated ???amp. 30/40 (30 slots/40 circuits max.) Ten full size breakers can be replaced with split breakers (Except in "Hey, that's our work" land). Either the label will spell out "30 circuits max" or the wiring diagram shows you that some may be doubled. If it is exposed you will see the difference in the tabs on the bus, some may be notched to allow split breakers, others not. Most would be electricians will pull out the simple metal clip that prevents the split from going where it does not belong.

There are panels out there that are rated 8/16 - 12/24 - 12 -16 - 20/20 - or 20/40 so on and so forth. Except for the Cutler Hammer which has 42, all 40 slot panels do not allow splits.

As Chad touched on, the biggest issue is if someone connects a multiwire circuit improperly pulling power from a split that is pulling power from only one side of the bus. But there are Quad splits that allow proper connection of either 220v or multiwire to either the two exterior terminals or the two center.

Ok, my wrist hurts now.

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