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We noticed during our home inspection the main panel has only six general lighting circuits and seven 2-pole circuits/breakers. There were only two areas where 240V outlets would be used. Why would they have so many 2-pole breakers? Is this normal or will it cause any problems/safety issues?

Chris O
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Christopher Bossa
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    Were the breakers marked? Did you try tuning them off? Did you get a picture of the panel? Did you get a picture of the panel with the cover off? Those two pictures should be included as part of a home inspection. – longneck Nov 06 '15 at 13:25
  • You should really post a photo of the panel. – paulmz Nov 06 '15 at 14:51
  • Added picture, hard to tell – Christopher Bossa Nov 06 '15 at 15:02
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    It is hard to tell with "that" picture!! – Michael Karas Nov 06 '15 at 15:06
  • Could you please add the unit (V) to your number? On the first read I thought you had 220 of the breakers, which sounds really much. – Paŭlo Ebermann Nov 06 '15 at 17:33
  • These breakers - are they rated for 220V or are they really 220V circuits? Circuit breakers trip when the current exceeds their trip rating, of 10 amps or 20 amps or whatever they're designed for. – Criggie Nov 06 '15 at 22:12
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    @Criggie They're likely rated 120/240 volts, as I believe that's typical of most breakers used in 120/240 volt systems. – Tester101 Nov 07 '15 at 04:20

3 Answers3

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By "220 breakers", I'm going to assume you mean double pole breakers. It's also difficult to speculate without actually seeing the panel, or being on site. But here are some thoughts.

Just because a double pole breaker is used, doesn't necessarily mean it's feeding a 240 volt circuit. In some areas, it's common to use double pole breaker to feed multiwire branch circuits. Which means the double pole breakers could be feeding two 120 volt circuits, instead of a single 240 volt circuit. This is likely the case if you see a bunch of 15, and/or 20 ampere double pole breakers.

It could also be that electricity, is the common fuel source in your area. For example you might have electric dryer, electric range, electric heat, electric hot water, electric A/C, water treatment equipment, secondary panel(s), etc. Having all electric appliances, can make the double pole breaker total jump quite a bit.

Tester101
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  • I can confirm the second paragraph. Many of my lighting circuits use double pole breakers. (Canada). – user19474 Nov 06 '15 at 17:25
  • In all areas subject to the NEC, 2-pole CBs must be used on MWBCs. - 210.4(B) Each multiwire branch circuit shall be provided with a means that will simultaneously disconnect all ungrounded conductors at the point where the branch circuit originates. powerdesigninc.us – Mazura Nov 07 '15 at 02:35
  • @Mazura That requirement is met with handle ties as well, so a double pole breaker is not required for MWBCs. – Tester101 Nov 07 '15 at 03:57
  • Either or. It's the, "it's common" part I don't like. As of the NEC two thousand-something, MWBCs are to "be provided with a means that will simultaneously disconnect all ungrounded conductors". IME, it's not common, but it is now however required by code. 2-pole CBs (or their equivalent!) must now be used. – Mazura Nov 07 '15 at 04:09
  • @Mazura Maybe I've had one too many, but I'm not following your point. To meet the requirements of the code you pointed out, you can use a double pole breaker, OR a handle tie to connect two single pole breakers. However, it's more common to use double pole breakers for MWBCs (at least in areas I've lived), than to use handle tied single pole breakers. – Tester101 Nov 07 '15 at 04:17
  • That last sentence of your comment is somewhat how I expect it to appear in the answer; that's the missing information. And ideally including, "To comply with today's code." Currently, it reads as if you may find DP breakers used for MWBCs, 'cause that's like a good idea. - No. It (either or) IS required. ~ "In some areas, it's common to find, and it is now required by the NEC, that DP or handle-tied CBs are used to feed MWBCs." or "In some areas it's required by code that" ~ OP says they only have two 220 outlets; then they've got a box full of MWBCs (assuming no shenanigans). – Mazura Nov 07 '15 at 04:53
  • @Mazura I guess what I was trying to say is "in some areas, MWBCs are common". – Tester101 Nov 07 '15 at 05:39
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Things that take 220 (actually 240, for the most part in the US system) and don't always have outlets - electric water heaters, electric stove/range/oven, electric resistance heat (typically but not always electric baseboard), air conditioner, heat pump and feeds to subpanels.

And, of course, MWBCs (Multi-Wire Branch Circuits) which have 120V outlets.

A multi-wire branch circuit (MWBC) is commonly used to provide the code-required two 20 amp circuits to a kitchen countertop area, though they can be used in other places. Typically wires are red, white, and black, plus a bare ground wire. The circuit (if an MWBC) will be fed from two side-by side breakers - they should be tied together or a dual-pole breaker under current code, but some older installs will have non-tied breakers.

There is 120V between red and white, 120V between black and white, and 240V between red and black. If both red and black are connected to an outlet on the hot (brass) side, the tab between the halves of a duplex outlet must be broken - we get the occasional "I replaced an outlet and the breaker (sometimes evene the main breaker) tripped as soon as I turned it back on" stories that are frequently from not removing that tab on a MWBC.

To the extent that there are loads on both "sides" of the circuit, current in the neutral wire is reduced to only the difference between the loads - so if one side has loads operating that are 7.5A, and the other has loads operating that are 9.5A, the one hot carries 7.5A, the other hot carries 9.5A and the neutral only carries the difference - 2A.

Ecnerwal
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  • This answer could benefit from an explanation as to why MWBCs are on DP CBs and what they are, which I have at length, tried to convince @Tester101 to also include. – Mazura Nov 07 '15 at 05:04
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    @Mazura http://diy.stackexchange.com/a/74739/18078 – Ecnerwal Nov 07 '15 at 12:26
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Electric baseboard heaters are a common reason for "lots" of double breakers.

Jeff Pritchard
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