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I'm attempting to map out our home electrical breaker panel. The labels written by the electrician 20+ years ago aren't super helpful, so I've having a go making things a bit clearer.

I have several breakers just labeled "Split". No description other than that. Each one is two 15 amp breakers "linked" (bridged?) together. What I mean by linked is that there is a piece connecting both of them so they have to be flipped at the same time.

I have three sets of these, which would make a total of 90 amps. Quite a bit considering the house only has 250 amp service.

Any ideas what these "Splits" are? The only other place on the panel with large "links" are for the big appliances (stove, dryer, air conditioner).

Thanks.

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My guess is these might be multiwire branch circuits for use in kitchen receptacles. In this type of circuit, the two hot wires (180 degrees apart in phase) are used to power different receptacles in the kitchen so high-current appliances don't all end up on the same circuit. Because they are opposite phases, they can share a neutral without fear of overloading.

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    While common in the kitchen, it's entirely possible to do this on other circuits around the home. So don't limit a search to just that part of the home. – BMitch Dec 5 '15 at 15:13
  • @friedo Thanks for the information. It looks like they are for the kitchen outlets. – user1159415 Dec 6 '15 at 4:34
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Friedo's answer is essentially correct regarding the multi wire branch circuit except if these are 15 amp circuits they could not be used to feed the kitchen receptacles. Those are required to be 20 amp circuits.

The code requires multi-wire branch circuits to be fed with either a multi-pole breaker or two breakers tied together with an approved handle tie. You appear to have the latter.

I just wanted to clear up a misconception many people have about how to calculate the total load of your panel. You said-

I have three sets of these, which would make a total of 90 amps. Quite a bit considering the house only has 250 amp service

We don't add all the breakers up to determine the load on the panel. The main panel is required to be sized large enough to supply the calculated load of the house not the sum of the installed circuit breakers.

(If you had a 200 amp panel (the normal maximum size for a residential service) with 40 breakers installed and they were all 20 amp breakers that would total 800 amps. Far exceeding the maximum of the main breaker. If the breakers were 15 amp breakers it would still add up to 600 amps.)

A residential load calculation is a fairly involved calculation but even an all-electric house of average size wouldn't normally exceed 150 amps so a 200 amp panel is plenty of capacity.

So your breakers are good. It is a safe installation according to the National Electrical Code and a normal practice in electrical installations.

Happy Day!

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    just to correct archonosx on a tiny detail. the current code requirement is for 20A on split kitchen circuits. however, thats relatively recent, and there are many homes that still exist with non split and 15A split kitchen outlets, both done to code requirements that have since been changed – personal privacy advocate Dec 5 '15 at 14:51
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    To phrase the load calculation differently, the breakers tend to be sized according to the wiring. The wiring for a circuit may support up to 20 amps, and the main connection may support up to 200 amps, so you'd install breakers appropriate for those wires. The main will trip if you pull too much from multiple breakers, while the individual circuit will trip if you pull too much for that individual circuit. – BMitch Dec 5 '15 at 15:11
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    not sure why its misleading. maybe the geography issue is what your all pissy about. here in ontario, where i wrote the comment, and the rules of ontario apply, its 100% correct. dont be such an american - the world does exist outside of the USA. now, since i don't have a copy of the electrical code from the 60's, it will be kind of hard to document the old kitchen outlet rules. the current code allows 15A or 20A splits (but they must be tamperproof). everything within 1.5 m of any water source has to be on a GFCI protected circuit. its all governed by OEC 26-700, 26-710, CSA 22.2. – personal privacy advocate Dec 5 '15 at 21:11
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    forgot to include the fact that the code was amended in only 2002 to allow for 20A outlets in the kitchen. well within what i would consider "relatively recent" – personal privacy advocate Dec 5 '15 at 21:33
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    just to clarify once again, i am referring only to the Ontario Electrical Code (OEC). we don't use a national code (even though there is one) for regulation and enforcement. each province has their own specific code that varies a little and a lot from every other province. if your citation is for the OEC being amended in 1999, then good for you. send my your address and i will courier you a big bag of who gives a f*ck. this is getting to be a really stupid conversation at this point. – personal privacy advocate Dec 6 '15 at 4:32
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"Split" is a common abbreviation for a "ductless Mini Split air conditioner". Do you have anything that looks like these in your house? http://www.homedepot.com/b/Heating-Venting-Cooling-Air-Conditioners-Coolers-Air-Conditioners-Ductless-Mini-Splits/N-5yc1vZc4m1

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