240V 3 way switching.....

[mx842]

Looks like I have run into another stumbling block. Can you hook up 240V lights controlled by 3 way switches?

I have 5 high bay light fixtures that I have already installed in the ceiling of my shop and one of them over my spray booth will be switched at just one location. The others I want to be able to control two rear and two forward from two different places, on the front wall and on the back wall.

I ran all my wires and was about to hook up everything and then I remembered that I want to run these lights off 240V rather than 115 because of the difference in Amp draw.

I guess I could move all the switches to one, more central location and forget about the 3 way switching but if it would work it would be nice to be able to control them from two places.

 

[jeff000]

The current draw is the same. Each wire just sees less current, but the panel sees the same.

So use the 120 and make it easier.

There are a few ways you could 3way the 240 though, but I would use a contactor. It's the least complicated way.

 

[Charles (in GA)]

I assume this is a detached structure. Code does not allow for lighting circuits above 125v for residential. How much amp draw are these fixtures? 400 watt MH draws about 480 watts total and exactly 4.0 amps each. You could have as many as four on a single 120v circuit, and be at the 80% (16 amps) point on a 20 amp circuit.

Charles

 

[jeff000]

I assume this is a detached structure. Code does not allow for lighting circuits above 125v for residential. How much amp draw are these fixtures? 400 watt MH draws about 480 watts total and exactly 4.0 amps each. You could have as many as four on a single 120v circuit, and be at the 80% (16 amps) point on a 20 amp circuit.

Charles

The code issue is a good one. I wasn't thinking about that since he said shop and spray booth I didn't associate that with a residence.

Although you may get a deviance if you pushed the issue if it is detached and permitted as a business.

 

[ishiboo]

Easiest way IMO is to use a 120v coil contractor powered by the 3-way circuit which remains 120v, to switch the 240v lights.

That's just me.

 

[Aceman]

Easiest way IMO is to use a 120v coil contractor powered by the 3-way circuit which remains 120v, to switch the 240v lights.

That's just me.

This is how I do it as well. I'll haul a neutral out with the 240v circuit just for the coil on the contactor. Tap one leg on the line side of the contactor for the control circuitry, run around to your switches and back to the contactor coil. You could eliminate the neutral if you found a contactor with a 240 coil too. I simply like contactors with 120v coils because they are everywhere, and I usually have a spare one on my truck.

This way you have ONE breaker running the lights and controls, so there is no question power is off when you go to work on your lighting circuit.

 

[mx842]

I have thought about this all day and have decided to just rewire the fixture to run off 120v and forget about it. There will be 4 lights total and they will be switched to run in pairs, if that makes any sense. the two front lights will run most of the time when I need light and the two rear lights won't get used hardly at all. I have one that will be all by itself over the area where I will be loading and unloading my powder coat oven.

Thanks for your help.