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I am working on an electrical upgrade for my garage. Some equipment I have requires 20A 220V power. Other equipment only needs 15A or 20A 110V. I would like to run in from a single circuit protected by a dual pole 20A breaker.

Are there any NEC restrictions to wiring 220V and 110V outlets to the same circuit.

Here is my wiring diagram:

110V & 220V wiring diagram.

  • AFIK all 240 V circuits are limited by code to a single 240 V receptacle. – Jim Stewart Oct 16 '17 at 17:47
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    @JimStewart -- can you get me a Code cite on that please? I'm not sure where this belief stems from, but I haven't been able to put it on a solid footing at all... – ThreePhaseEel Oct 16 '17 at 22:37
  • @JimStewart agreed. I think that's the case, but couldn't find the code cite that allows or prohobits it. – Harper Oct 16 '17 at 22:57
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    @JimStewart I think that idea comes from the fact that in residential work, you're usually dealing with 240V circuits for single larger load appliance (30,40,50 amp). It's not that common to be dealing with 240V 20A circuits in homes (in the US), so it's easy to think the limiting factor is the voltage, when in reality it's the equipment that will be connected. – Tester101 Oct 17 '17 at 11:51
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Use a two-pole, common-trip breaker and you're set

Since you're dealing with a 20A circuit (where 15 and 20A receptacles are allowed), you can set up this mix of receptacles provided you handle it as for any other combination 120/240V load: all four wires need to be there, as shown in your drawing, and the breaker that protects it needs to be a two-pole, common trip unit (no handle ties here!). This is written into the Code, albeit somewhat awkwardly, as 210.4(C) exception 2:

(C) Line-to-Neutral Loads. Multiwire branch circuits shall supply only line-to-neutral loads.

Exception No.1: A multiwire branch circuit that supplies only one utilization equipment.

Exception No.2: Where all ungrounded conductors of the multiwire branch circuit are opened simultaneously by the branch-circuit overcurrent device.

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