240V 3 way switching.....

[mx842]

can you switch 240V lights so that they can be controlled in two places?

I really want to use my high bay lights in my barn. It would be nice if I could split them, two in back and two in the front and put them on 3 way switches so both sets could be turned on and off from either end of the shop.

I could wire them to run off 115V but they use too much juice that way, double what they use when wired 240V.

 

[LD1]

I am not an electrician, so take this for what its worth.

I would wire them 120v if you want the 3 way. They wont use more "juice" if you are refering to watts when you sat "juice". It is true that they will pull double the amps, so the wires have to be sized accordingly, but even if they are 1000w bulbs, that is still under 10 amps per light on 120v. So you could run 2 of them lights on a 12ga 20a circuit.

But either way, total wattage (and what you have to pay for) wont be much difference either way. Maybe pennies a month on 240v just because it is more "efficient". But no noticable difference IMO.

If you really want them on a 240v circuit and 3-way, you will need to wire it to a relay or some other means of delivering the 240v. Because I dont thin they make 3-way switches for 240v since 240v involves 2 hots and not just the one like 120v. So you will have to wire a 120v 3-way circuit tied to a relay (same as you would wire a typical 3-way in a house, only use a relay instead of a lightbulb). And from that relay, feed your 240v to the lights.

But as I said, I think 120v would be simpler. What are the wattage of the lights??

PS: remember I said I was not an electrician, so take my advise for what its worth.

 

[hr3]

How do you wire a light that requires 240 Volts to 3-way switches

Read this.!!!

 

[grsthegreat]

I am an electrician, and whenever i find a 240 volt light requiring 3 way, 4 way, etc wiring i use a contactor.

A general lighting contactor only cost in the range of $40.00 and is real easy to install. My arena uses two separate 240 volt , 20 amp circuits to light a combination of 1000 watt and 250 watt MH lights. I simply wired all of them to a 4 pole contactor that has a 120 volt coil. Then i wire the coil as you would wire a normal 3 way circuit. You can wire the contactor with a 15 amp circuit and 14 ga wire to save $$$ on wire.

 

[mx842]

I am not an electrician, so take this for what its worth.

I would wire them 120v if you want the 3 way. They wont use more "juice" if you are refering to watts when you sat "juice". It is true that they will pull double the amps, so the wires have to be sized accordingly, but even if they are 1000w bulbs, that is still under 10 amps per light on 120v. So you could run 2 of them lights on a 12ga 20a circuit.

But either way, total wattage (and what you have to pay for) wont be much difference either way. Maybe pennies a month on 240v just because it is more "efficient". But no noticable difference IMO.

If you really want them on a 240v circuit and 3-way, you will need to wire it to a relay or some other means of delivering the 240v. Because I dont thin they make 3-way switches for 240v since 240v involves 2 hots and not just the one like 120v. So you will have to wire a 120v 3-way circuit tied to a relay (same as you would wire a typical 3-way in a house, only use a relay instead of a lightbulb). And from that relay, feed your 240v to the lights.

But as I said, I think 120v would be simpler. What are the wattage of the lights??

PS: remember I said I was not an electrician, so take my advise for what its worth.

The fixtures are 400W medal halide high bay lights. After thinking about it throughout the day I had come to the same conclusion as you, I think I'll just rewire them for 120 volts and forget about it. I'll have to rerun my feed from the panel to the first light but that would probably be the best way to work it out with the least problems.

I had looked around and saw the thread that talked about working them off of relays but couldn't find anything explaining just how to actually do that so at that point I had figured I would have to just go 120V but thought I would give it a shot here to see if anyone else had any other ideas.

 

[LD1]

With them only being 400w, and capable of running on either 120 or 240, I just dont see the advantage of 240 in your case. How many lights are you talking? Depending on how long the runs are, you could probabally wire 4 of them on a 120v 20A circuit with 12ga wire. And that would light up a pretty good sized building right there.

At 400w each, thats 3.33A on 120v. Or 1.66A on a 240 run. But like I said (and I think you figured out), wattage is still going to be the same. And your power company bills you based on watts, not amps. So you wouldnt save much going to 240v

 

[mx842]

I am an electrician, and whenever i find a 240 volt light requiring 3 way, 4 way, etc wiring i use a contactor.

A general lighting contactor only cost in the range of $40.00 and is real easy to install. My arena uses two separate 240 volt , 20 amp circuits to light a combination of 1000 watt and 250 watt MH lights. I simply wired all of them to a 4 pole contactor that has a 120 volt coil. Then i wire the coil as you would wire a normal 3 way circuit. You can wire the contactor with a 15 amp circuit and 14 ga wire to save $$$ on wire.

I'm trying to wrap my brain around this but just can't seem to make a connection.:ashamed: Is there somewhere that might have a drawing of what you are speaking of? Although if these things don't cost anymore to run off of 120v than they do on 240v I may as well just wire them 120v and forget it, does that make sense?

 

[grsthegreat]

I'm trying to wrap my brain around this but just can't seem to make a connection.:ashamed: Is there somewhere that might have a drawing of what you are speaking of? Although if these things don't cost anymore to run off of 120v than they do on 240v I may as well just wire them 120v and forget it, does that make sense?

ill go take a picture of my contactor box. Wiring them 120 is fine, as long as you dont have more than 4 of the 400 watt lights on one circuit.

 

[grsthegreat]

Ok, here goes contactor basic wiring 101.

On this application i placed contactor inside waterproof box on arena light pole. It has two separate 220 volt incomming circuits and two lighting load 220 circuits (output). It also has a 120 volt control feed (coil circuit). The 120 feed closes the contactor and that completes the 4 circuits.

I have a cabinet shop io wired a few years back that had 70 - 200 watt light fixtures. All controlled by 1 toggle switch 3-wayewd between two separate entry doors. With a single flip of one toggle switch, 14,000 watts of lighting is turned on and off.

 

[mx842]

Ok, here goes contactor basic wiring 101.

On this application i placed contactor inside waterproof box on arena light pole. It has two separate 220 volt incomming circuits and two lighting load 220 circuits (output). It also has a 120 volt control feed (coil circuit). The 120 feed closes the contactor and that completes the 4 circuits.

I have a cabinet shop io wired a few years back that had 70 - 200 watt light fixtures. All controlled by 1 toggle switch 3-wayewd between two separate entry doors. With a single flip of one toggle switch, 14,000 watts of lighting is turned on and off.

Thanks, I have wired contactors before because all the ovens I built use them to operate their heating elements. I was just having problems getting the 3 way part packed into the picture. My brain goes into overload sometimes when I get side tracked from the original plan and won't let anything else in and I have to re boot it sometimes and start all over.:laughing: That's a problem on my end and has no bearing on your teaching abilities so don't take offense. Sometimes I have to have a pic or drawing of the whole pie before I can sit down and dissect one simple piece of it.:confused3:

Since I have already run all my wires and as it seems the wire I have run will be big enough for the 4 lights that I will have on the circuit It would be simpler to just rewire the lights to run off 120V and forget about it.