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I posted this question but for some reason I can't get back into my account:

Is it up to code to do a parallel circut with 220V? Is there a limit to number of splices?

Most things I see with 220V have both hot legs going through the switch or relay, current "returns" through the switch. Is it against code to wire one leg directly to the equipment and the other leg is switched as opposed to having both legs switched. It seems useless and a waste of wire to switch both legs.

Basically https://i.sstatic.net/UsUm0.png vs https://i.sstatic.net/OhRII.png (minus the GFCI as I'm not allowed to have that)

As a bonus question. I assume I need a "motor rated switch" as standard switches can weld due to the high startup current. Is this one legal\safe?

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  • You have a neutral and safety ground run to the target device along with the two hot legs that make up the 220VAC. Switching off both of the hot legs at the switch assures that there is no direct hot connection in the target device when anyone would expect it to be OFF. It is not any significant use of extra wire to switch both hot legs.
    – Michael Karas ♦
    Commented Jan 17, 2017 at 10:42
  • Many older baseboard 240V heaters were controlled by switching only 1 leg in the past but it creates the potential to get shocked by 120V when the thermostat is turned off. can it work yes is it safe I don't think so. Since you are looking for a motor rated switch this could be more hazardous because circuit breakers usually need to be 300% to allow for starting currents on motors and a winding failure could cause excessive fault currents if both legs are not opened.
    – Ed Beal
    Commented Jan 17, 2017 at 14:06
  • With your application switching only one side of the line, won't even work. You are adding a bypass switch, not simply making/breaking a circuit to turn something on or off.
    – Tyson
    Commented Jan 17, 2017 at 14:59
  • Hi! You have a couple of user accounts. If you’d like to merge them (which will allow you to edit, comment on any of your posts and accept an answer on your question), please see the instructions. Welcome to the site!
    – Niall C. ♦
    Commented Jan 18, 2017 at 3:35

1 Answer 1

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Switching both hots is necessary here as you have a two pole relay

Since you have the switch wired as a bypass switch, you need it to have the same number of poles as the thing you're bypassing. Otherwise, closing the bypass switch wouldn't do anything as the circuit still wouldn't be closed when the relay was open.

If the relay was single pole, your bypass switch could be single pole...

If the relay was a single pole relay that switched one leg/side of the motor circuit, you could use an appropriately rated manual motor controller as a single pole bypass for the relay. Motor controllers do not need to be all-pole devices as long as they aren't serving as disconnecting means, as per 430.84.

But you may need to get one of those two-pole switches no matter what

If you can't see the breaker box from the pump, then you'll need a two-pole switch, separate from your bypass switch, at the pump anyway to serve as a motor/controller disconnecting means satisfying 430.102 and 430.103. (You'd need this even if the bypass switch was not present!)

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