Checking this plan for outside lighting


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Old 09-15-15, 01:59 PM
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Checking this plan for outside lighting

I'm helping my brother wire some lights for a sport court. There were a couple things I was hoping that someone could help double check for me. There are 3 lights that are rated for 1500 Watts @ 240 Volts each. When I did the math I calculated these to be 18.75 Amps. ((1500 * 3) / 240). When I add in a 25% extra factor I come to 23.4 amps so I'm rounding up to 30 Amp circuit.

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SEE PROPOSED PICTURE HERE (Sorry for the rough drawing)

We need to add a sub-panel since there is no more room in the main panel. From the sub-panel we will run a 30 amp (240V) circuit for the lights and a 20 amp GFCI circuit for some outdoor plugs. Does the wiring look right?? Am I correct in thinking that the 240V doesn't need a neutral and that 10/2 wire will work?

Any feedback would be greatly appreciated. Love the forum and support!!!
 

Last edited by ray2047; 09-15-15 at 02:48 PM. Reason: Add image.
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Old 09-15-15, 02:05 PM
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What type of light fixtures are these? Some cannot be used on circuits greater than 20A.

Are these lights "continuous loads", defined by code as intended for use longer than 3 hours at a time?

What are the total distances involved from the panel to each light post? There could be voltage drop considerations.

You are correct that a 240V circuit does not use a neutral.
 
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Old 09-15-15, 02:19 PM
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I would install a small panel at the sport court. Run a feeder to the court and split it off there.
 
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Old 09-15-15, 02:29 PM
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Thanks for the reply. I'll check on the type of light fixtures.

I suppose that they will be intended to be used for over 3 hours, sometimes (depending on the time of the year). So I guess by definition, yes?.?.?

Panel to light switch ~100 feet. Switch to light ~85 feet.
 
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Old 09-15-15, 06:57 PM
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You could easily split up the lights into 2(or 3) circuits by installing a relay(s). That is how it is done on outdoor ballpark light poles.
 
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Old 09-15-15, 07:07 PM
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ibpooks
What type of light fixtures are these?
@ipbooks: These are Quartzliter QL lights. Here is the website: Hubbell Outdoor Lighting : Products : Floodlighting : Quartzliter QL

I couldn't see where these would only be allowed on a 20 Amp circuit. (Of course, I didn't see anything to the contrary either.)

With all that, would the way I have it in the diagram work?

Thanks!!
 
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Old 09-15-15, 08:28 PM
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It would be pretty hard to determine if a fixture was limited to a certain size circuit. Normally it is assumed that a lighting fixture will not be fused at more than 20A. This is due to the internal wiring in the fixture.

That aside.... your diagram looks correct. You wont be able to use a standard or even a two pole light switch to control those lights as the switches are limited to 20A maximum. You could use a switch like in the link below. Also comes in weatherproof for outdoor use.

GE 30-Amp 240-Volt Non-Fuse Indoor Safety Switch-TGN3321CP - The Home Depot

As a second aside..... those fixtures are inexpensive and the replacement tubes are also inexpensive but they aren't really an efficient use of power. A metal halide fixture will cost more but give you a lot more light for less energy used.
 
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Old 09-15-15, 08:29 PM
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Just a note for the techs:

I looked at product specs, the fixture may be wired for 120 or 240, depending on the lamp chosen.
 
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Old 09-16-15, 06:27 PM
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You wont be able to use a standard or even a two pole light switch to control those lights as the switches are limited to 20A maximum.
Here is one.

Leviton 30-Amp Industrial Double Pole Switch - White-R62-03032-2WS - The Home Depot

those fixtures are inexpensive and the replacement tubes are also inexpensive but they aren't really an efficient use of power. A metal halide fixture will cost more but give you a lot more light for less energy used.
Agree! The quartz lamps won't last long and will need frequent relamping.
 
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Old 09-16-15, 06:51 PM
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May want to look at LED options too. The payback may not be too long when you figure in the smaller circuits needed along with the reduced wattage.
 
 

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