1

I am in the process of renovating the kitchen in my 100+ year old home, including cleaning up the electrical “situation” the previously owner attempted and bringing up to code.

NEC requires that there be two 20A dedicated small appliance circuits in the kitchen. My current breaker box, which was completely replaced by an licensed electrician, when we purchase the home last summer, has a tandem 20A-20A breaker labeled for the kitchen outlets.

Does a tandem breaker satisfy the code requirements as two circuits, given I run one set of outlets on one of the tandem breakers and the remaining on the other tandem breaker?

Thanks in advance for your help!

isherwood
  • 137,324
  • 8
  • 170
  • 404
Tbrannock
  • 11
  • 1
  • 2
  • 1
    To anticipate comments by experts on the code: Two tandem breakers are electrically separate breakers and so the two circuits are independent circuits. AFIK there is no reqt for the microwave to be on a dedicated circuit. – Jim Stewart Jun 26 '19 at 10:34
  • Is this a house you're flipping, or will "someone you actually care about" be living there? Did the seller replace the panel, or did you? – Harper - Reinstate Monica Jun 26 '19 at 11:34
  • 1
    Welcome to DIYSE. In the future, please ask one question per post. Your second is a duplicate of this one, so I've removed it. Good luck with your project. – isherwood Jun 26 '19 at 13:16
  • @Harper Your question makes me cringe. – DonBoitnott Jun 26 '19 at 13:40
  • @DonBoitnott I suspect Harper is going to suggest that if you will actually be living there then you should add more circuits. Not a safety/code issue but a practical living issue. – manassehkatz-Moving 2 Codidact Jun 26 '19 at 13:58
  • 1
    @DonBoitnott Yeah, this is how the crazytrain gets to this sad point. a) seller is forced to upgrade electrical as condition of sale, so does absolute bare minimum, note double-stuff breakers; which b) limits remodeler's options and/or remodeler focuses on bare compliance and neglects usability. My hope is to head that off. – Harper - Reinstate Monica Jun 26 '19 at 14:26
  • We had the panel replaced after purchasing the home (we didn’t want the seller “fixing” anything else) and in the process had a larger service panel installed, so we definitely have room to add additional circuits if needed. We are down to the studs in the kitchen and my hope is to do the kitchen electrical correctly, permits and all. – Tbrannock Jun 26 '19 at 15:11
  • Does each side of the tandem breaker have its own associated neutral? Or is it a single neutral shared between the two? – Nate S. Jun 26 '19 at 17:41

2 Answers2

4

Tandem breakers are totally legit and are two totally separate circuits. In fact they can ONLY be two totally separate circuits. The error that people sometimes make is in thinking that they can use the two poles of a tandem breaker as a 240V circuit, and THAT will not work.

JRaef
  • 14,944
  • 1
  • 18
  • 40
  • If the tandem is placed in the panel so that it is attached to separate busses it will deliver 240v is that a code violation? – Kris Jun 27 '19 at 12:17
  • You cannot place a tandem breaker so that it taps off of different buses. The thing that makes it a "tandem" is that it has ONE stab for the bus and then two breakers coming off of that stab. two separate circuits from that point on, but only one bus connection point. – JRaef Jul 01 '19 at 18:46
  • Guess I’m thinking of a thin 2 pole like https://www.amazon.com/General-Electric-THQP220-Circuit-Breaker/dp/B000BPE71W – Kris Jul 01 '19 at 18:59
4

Sure, but they can't share neutral if they're on a duplex.

First, take any hardwired loads (and I count installed appliances like microwave and dishwasher whose sockets are only accessible by pulling the appliance). Take their amp rating. If they are a water heater or could plausibly run for 3 hours, add 25%. Total up the hard-wired loads for a circuit. If they take more than 50% of available amps, then you can't have any receptacles on the circuit.

This makes many circuits effectively "dedicated", except e.g. a built-in 11A microwave could share a circuit with a 1A exhaust fan, but not receptacles.

Kitchen receptacle circuits are a big mess in Code. In Europe, most heat appliances like grills, kettles, coffee makers etc. are 2000-3000 watts. However, in the U.S., they are clamped to 1500 watts due to our 120V voltage, and every manufacturer uses all of it. Kitchen receptacle circuits are 20A (2400 watts) -- which means if you run two heat appliances at once, you probably trip.

That is why NEC requires two countertop circuits. However realistically that is not enough. Wanting to toast your hamburger buns while the Foreman grill cooks your burgers is perfectly reasonable, and "2 circuits" is no protection - it only means a 50/50 chance of both being plugged into the same circuit. This ends up being a minefield for the chef, because they don't know which receptacles are on which circuits.

Well, hold on. We don't wire electricity to pass code. We wire electricity to use it. So my philosophy is think about how the kitchen will be used; if you do more than reheat Chinese, then I would just "cut to the chase" and fit 1 circuit per receptacle. You can explain that to the chef in 10 words.

The refrigerator has a lot of options, and it is often put on the kitchen receptacle circuit. While legal, it's very undesirable. First, if you get into the "2 heat appliances" bind, you'll trip the fridge too. Second. receptacle circuits must be GFCI. You really, really, really do not want the fridge on GFCI protection; it's grounded, all the sparky things are in the bottom back, and you're unlikely to drop it in your sink. However fridges tend to trip GFCI's quite a lot due to their big electric motor.

All of this tends to add up to "dedicated circuit for fridge".

On the duplex breakers, which I like to call "double-stuff", those are fine, with a few caveats.

  • You must never, never even think of hooking one to a multi-wire branch circuit, because it will overload the shared neutral. It must be two completely separate circuits with separate neutrals, wired in dual /2 or single /2/2 cable. Never /3.
  • This type of breaker is not available in GFCI or AFCI, so it can't be used on an AFCI circuit, and will require a (cheaper) GFCI deadfront or receptacle if that is called for on that circuit.
Harper - Reinstate Monica
  • 300,628
  • 26
  • 286
  • 734
  • What type of panel was installed? Those breakers may not be listed for that panel. If you have the room, do not use them. You know your needs and having extra circuits in the kitchen is always the best way to go. –  Jun 27 '19 at 05:02