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Thread: Splitting 220

  1. #1
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    Default Splitting 220

    I will be helping a friend change out an electric water heater next week and I discovered that the 220 breaker for the W/H also controls the outlet that the refrigerator is plugged into. I recall hearing that you can't split a 220 circuit to feed a 110, and not being an electrician, I don't remember why. Can someone explain it
    I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!

  2. #2
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    Default Re: Splitting 220

    You can if there's a neutral. Sometimes people will tie the neutral connection of the 120V outlet to the ground wire to make it work, but that's not considered safe.

    Regardless, it's a violation of code to do what you've described. The water heater requires a dedicated circuit.

    The proper way to split it out would be to install a subpanel in the circuit at the point you want to split. However, that subpanel would need to have separate ground and neutral going back to the main panel; ground and neutral may not be bonded in the subpanel.
    The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.

  3. #3
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    Default Re: Splitting 220

    The other problem; the heavier gauge wires and breaker for the 30 amp circuit will not trip for the 20 amp outlet like it should. Which is why its a bad idea and against code.

  4. #4
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    Default Re: Splitting 220

    I seem to recall something about it unbalancing the circuit. Probably because the shared neutral could backfeed the other leg of the 220 if there were ever a fault of some sort.
    I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!

  5. #5
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    Default Re: Splitting 220

    I don't think the imbalance would be a huge issue, although the fridge circuit is probably relatively unprotected like this. I'd do something different for the fridge and leave the WH to itself, as it should be. Double-breakers are sometimes reluctant to fully trip with only one side overloaded, and I've seen problems with that. Sometimes the breaker partially trips and burns the contacts inside leading to breaker failure and/or undercurrent to the one side. That's not good for motors and electronics. I learned about this from hearing a 60Hz hum in a panel and tracing it to a double-breaker as you describe. The breaker was trying to trip but was just short of being able to. It smelled burnt when I removed it so I put a new one in and rewired the single to another lightly-loaded circuit since the panel was over-full already and a new panel out of the question due to cost. The new setup is still working fine.

    Lots of things that can happen in theory don't quite work out the same way in practice. I've seen what you describe numerous times and so long as the wiring can handle the current it seems to usually work well enough even if it's not code-worthy. The odds are against it being a problem, but that one mis-called bet could be lethal so it's best approached accordingly.

    Phil

  6. #6
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    Default Re: Splitting 220

    Quote Originally Posted by A. Spruce View Post
    I will be helping a friend change out an electric water heater next week and I discovered that the 220 breaker for the W/H also controls the outlet that the refrigerator is plugged into. I recall hearing that you can't split a 220 circuit to feed a 110, and not being an electrician, I don't remember why. Can someone explain it
    As others have said, the WH needs a 30A breaker, so it can't legally be run to a 15/20 receptacle.

    Also, since a typical 4500W element draws 18.75A if you did try to hook a receptacle to half of the circuit you would trip the breaker pulling over 11.25A at the receptacle, if the WH was running.

    And, you wouldn't have a neutral for the receptacle, unless you ran a new wire, which defeats the whole purpose.
    Good Luck from Columbiana, Alabama
    Maurice Turgeon, Hidden Content

  7. #7
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    Default Re: Splitting 220

    Quote Originally Posted by The Semi-Retired Electric View Post
    As others have said, the WH needs a 30A breaker, so it can't legally be run to a 15/20 receptacle.

    Also, since a typical 4500W element draws 18.75A if you did try to hook a receptacle to half of the circuit you would trip the breaker pulling over 11.25A at the receptacle, if the WH was running.

    And, you wouldn't have a neutral for the receptacle, unless you ran a new wire, which defeats the whole purpose.
    I was hoping you'd stop by this thread.

    My friend did mention that he's had issues with the breaker popping, or at least the waterheater not working. He's had the elements replaced with no improvement of function, or minimal improvement at best. Sounds like the issue with no hot water might actually be the circuit rather than the W/H itself. I think I may have the electrician over before we change the W/H, just to be sure that isn't the problem. The W/H is old enough to be replaced, so it's no big deal either way.

    Thanks for your input.
    I suffer from CDO ... Its like OCD, but in alphabetical order, LIKE IT SHOULD BE!!!

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