Wiring a switch for 110 volts

[Steven Wilson]

Tom, you're assuming that someone is using the same circuit - bad assumption. Just wire the switch once using the two poles that are there and be done with it. If you then want to rewire the motor, do it. If you want to wire in a new plug, do it.

[Rick Christopherson]

It doesn't matter what you do. Since it appears that this is a switch for inside the tool, and it is already a 3-pole switch, then there is no reason why you shouldn't switch the neutral wire, but there is also no compelling reason why you should either.

Contrary to some previous postings, even if the tool was 240-volts, you do not need to break both hots at the tool's on/off switch. A circuit breaker needs to break both lines, but not the control switch.

[Tom Veatch]

Tom, you're assuming that someone is using the same circuit - bad assumption. Just wire the switch once using the two poles that are there and be done with it. If you then want to rewire the motor, do it. If you want to wire in a new plug, do it.

Your're right. For some reason I was focused on the switch being in the wiring circuit. Guess that's because I've just completed hardwiring in a dust collector on a dedicated circuit that's controlled by a wall switch. What I said is only appropriate if the switch is located in the circuit wiring. If it's on the tool side of the wall plug, i'll buy switching both conductors.

[Mike Henderson]

If I had a two pole switch, I'd wire it to switch both sides of a 120V circuit. The reason is that you can't absolutely guarantee that the circuit won't get switched around, with hot coming in on the white wire. You may be very sure of your shop but if you move the tool to a different location, or sell it to someone else, it may get cross wired.

I certainly understand the logic of leaving the neutral side (the white wire) connected and only switching the hot side (the black wire) but I'd switch both.

Mike