Question about 210.6 in the NEC

[shaggyant]

When I look at 210.6 (A) in the NEC it says:

In dwelling units and guest rooms or guest suites of hotels, motels, and similar occupancies, the voltage shall not exceed 120 volts, nominal, between conductors that supply the terminals of the following:

1. Luminaires

https://up.codes/s/branch-circuit-voltage-limitations

The NEC definition of a dwelling unit is:

“a dwelling unit is a single unit, providing complete and independent living facilities for one or more persons, including permanent provisions for living, sleeping, cooking and sanitation.”

https://citel.us/en/what-is-the-nec...ctric Code,, sleeping, cooking and sanitation.

Based on this a free standing shop or garage isn’t one since there’s no bedroom. Thusly I can use 240v lighting. Am I wrong here?

 

[blue-5]

A garage is not a dwelling unit

 

[cybrdyke]

I think you're good to go, but your local inspector should probably get asked.
CD

 

[mike93lx]

Why the desire to use 240v lighting?

 

[shaggyant]

Why the desire to use 240v lighting?

Smaller wire. I can run all the lights off one switch and one run of 12ga NM-B

 

[mike93lx]

Smaller wire. I can run all the lights off one switch and one run of 12ga NM-B

Must be a lot of lights. A 120v 20a circuit can support a lot already.

Could do a MWBC with 12/3 as well.

Zoned lighting is really nice. Nothing having to turn everything on every time can be useful

 

[wyliesdiesels]

Smaller wire. I can run all the lights off one switch and one run of 12ga NM-B

damn how much lighting you running? are they incandescents?

 

[billconner]

damn how much lighting you running? are they incandescents?

Maybe he took the GJ advice to build bigger seriously.

 

[PCustoms]

Is a lighting load limited to a % of breaker rating?

 

[mike93lx]

Is a lighting load limited to a % of breaker rating?

If they will be on for more than three hours, then I believe it qualifies as a continuous load and requires 80% derating for the circuit

 

[shaggyant]

If they will be on for more than three hours, then I believe it qualifies as a continuous load and requires 80% derating for the circuit

Yes, running 240v gives me plenty of headroom after the 80% de-rating.

I want to run 18 of these at 100 watts each. But that would put me over on a single 20 amp circuit unless I run them at 240v

https://www.1000bulbs.com/fil/products/22191

I am planning on running a dimmer so having zoned lighting is just a waste of wire in my opinion unless I have to in order to avoid using 10ga wire.

 

[BrandonV]

Guessing that regulation is to keep people from zapping themselves on an Edison socket.

Clearly doesn't apply to a shop or garage.

 

[PCustoms]

Yes, running 240v gives me plenty of headroom after the 80% de-rating.

I want to run 18 of these at 100 watts each. But that would put me over on a single 20 amp circuit unless I run them at 240v

https://www.1000bulbs.com/fil/products/221961

How tall are your ceilings?

 

[shaggyant]

How tall are your ceilings?

It’s a 30x60 pole barn with 18 foot walls and open trusses. The lights will be about 17 feet above the floor.

 

[Stuart in MN]

I think many local inspectors will say that the 120vac limitation applies to everything on a residential property including outbuildings, and 240vac lighting will be only allowed for commercial properties. It's best to check with your local AHJ (authority having jurisdiction) to be sure. As far as that goes, with modern LED light fixtures the total load shouldn't be that large. Double check how many fixtures you'll need.

 

[mike93lx]

I want to run 18 of these at 100 watts each. But that would put me over on a single 20 amp circuit unless I run them at 240v

How do you figure that?

20 x 120 = 2400 x 0.80 = 1920

18 of those fixtures will be fine on a 20a 120v circuit

 

[PCustoms]

How do you figure that?

20 x 120 = 2400 x 0.80 = 1920

18 of those fixtures will be fine on a 20a 120v circuit

On top of that, does it make sense to have all 18 on at the same time, all the time?

Setting up a couple banks might make sense.

 

[shaggyant]

I think many local inspectors will say that the 120vac limitation applies to everything on a residential property including outbuildings, and 240vac lighting will be only allowed for commercial properties. It's best to check with your local AHJ (authority having jurisdiction) to be sure. As far as that goes, with modern LED light fixtures the total load shouldn't be that large. Double check how many fixtures you'll need.

Are you basing this on the property zoning? If so I’m zoned agricultural not residental. My house is on the property though. The code seems pretty specific in both where 240v luminaries are prohibited and its definition of a dwelling unit.

If it gets rejected I’ll just run it as a MWBC with a double pole switch and twice as many wires between the switch and the ceiling.

 

[shaggyant]

How do you figure that?

20 x 120 = 2400 x 0.80 = 1920

18 of those fixtures will be fine on a 20a 120v circuit

Sorry, 100 watts is the output not the input. They draw .99 amps each at 120V which of course can’t be found anywhere in the documentation except the lamp itself.

 

[shaggyant]

On top of that, does it make sense to have all 18 on at the same time, all the time?

Setting up a couple banks might make sense.

The shop I had before this I ran 15 high bay T5 fixtures with six bulbs each in 36x48. I had to set them up on three circuits with three switches due to the load at 120v but I can’t think of a single time I ever had only one third of the shop illuminated.

If I want the shop darker for some reason I’d prefer to use the 0-10v dimmer to lower light levels precisely without shadows.

 

[American Locomotive]

That's going to be one bright shop. Probably well over 100 fc with all 18 at full brightness. That being said, I suppose running the lights on 240v makes sense. You just need a double pole switch & breaker, and you can wire everything with 14 gauge.

 

[theoldwizard1]

damn how much lighting you running? are they incandescents?

AGREE !

You can have near daylight with LEDs on a single 120V 20A circuit !

 

[mike93lx]

Sorry, 100 watts is the output not the input. They draw .99 amps each at 120V which of course can’t be found anywhere in the documentation except the lamp itself.

Lights aren't rated for wattage output. I bet that setup would be fine at 120v

 

[PCustoms]

Lights aren't rated for wattage output. I bet that setup would be fine at 120v

A 100W equivalent LEd pulling 0.99A seems pretty inefficient. I'm not sure what's usually lost via the drivers....

I noted the spacing sheet listed THD > .9 , unless I'm way off that spec seems bass ackwards and raises some questions about the quality

 

[sparky 1971]

If it's zoned ag and it's an ag building, it's not a dwelling. I know everywhere is different, but we don't even need inspections for anything ad other than a dwelling that is on a farm. Have at it with the 240 volt circuits. However, 1800 watts will be fine on a 120 volt 20 amp circuit. 1800/120=15 amps. 20X.8=16

 

[sparky 1971]

A 100W equivalent LEd pulling 0.99A seems pretty inefficient. I'm not sure what's usually lost via the drivers....

I noted the spacing sheet listed THD > .9 , unless I'm way off that spec seems bass ackwards and raises some questions about the quality

It's a 100 watt fixture, the equivalent of a 250 watt metal halide.

 

[billconner]

If you're approach 80% of the breaker rating, just beware the inrush current can cause the breaker to trip. Based on price, I doubt that these fixtures have limiters on them. Just beware. When I was designing lighting I never exceeded 50% of the breaker with LED lights - and these were generally top end - $500-1000 each.

 

[PCustoms]

If you're approach 80% of the breaker rating, just beware the inrush current can cause the breaker to trip. Based on price, I doubt that these fixtures have limiters on them. Just beware. When I was designing lighting I never exceeded 50% of the breaker with LED lights - and these were generally top end - $500-1000 each.

But the 80% rule is only for continuous loads....

 

[PCustoms]

However, 1800 watts will be fine on a 120 volt 20 amp circuit. 1800/120=15 amps. 20X.8=16

.99x120x18≠1800

 

[mike93lx]

.99x120x18≠1800

The 0.99 is shenanigans, I bet

 

[Bad Habit]

Why not split them by 2 circuits and then control them through a contactor if you want to control all at the same time?

 

[KenC]

reading the light listing, it is a 14000 lumen fixture, and rated at 140 lumens per watt so OP is correct it is a 100w input fixture so all the math showing it on a 120v circuit above is correct.

Too bad they don't include a picture of the actual label with the current draw shown.

 

[sparky 1971]

.99x120x18≠1800

Where is the .99 amps per fixture coming from? They are 100 watt fixtures, 100 watts is .83 amps at 120.

20 fixtures X 100 watts = 1800 watts. 1800 watts ÷ 120 volts = 15 amps.


80% of 20 amps = 16

If they are really .99 amps, they are still under 20 amps. Sure, the lights could be on longer than three hours, but catastrophic failure isn't going to happen. It's no different than plugging a 1500 watt space heater into a 15 amp circuit and leaving it on all night. Breakers can run at the rated load, and a little more, indefinitely. And, if there is a concern, there's nothing wrong with connecting them to 240 volt, which is what the entire thread is about.

 

[PCustoms]

Where is the .99 amps per fixture coming from?

Sorry, 100 watts is the output not the input. They draw .99 amps each at 120V which of course can’t be found anywhere in the documentation except the lamp itself.

I've read the spec sheet twice, the lack of info and discrepancies would steer me away.

 

[sparky 1971]

I've read the spec sheet twice, the lack of info and discrepancies would steer me away.

I agree. I think they are P.O.S.'s based on the price alone, but since that isn't the topic I stayed away from that. The barn could probably be lit up better with nine or 10 good UFO fixtures for about the same amount of money, maybe just a little more cash. Thanks for opening the door for me.

 

[Shiftless]

I am planning on running a dimmer so having zoned lighting is just a waste of wire in my opinion unless I have to in order to avoid using 10ga wire.

It seems to me that you are planning for an incredibly bright shop and then relying on a dimmer to bring it down to a lower level. Don’t you need to run a separate wire to use the 0-10 volt dimmer function for those LED’s?
It seems to me that you could simplify and economize by hanging fewer of those fixtures and also wiring them so that they don’t all have to be on at the same time.

 

[micromind]

A serious advantage to using 240 for lights is that when applying a large 120 load (like a saw of some sort, etc.), the lights will dim much less that if they were 120 and on the same phase.

Given the choice, I always run lights at 240 in outbuildings.

 

[cybrdyke]

The reason the specs on this fixture are suspect is because it's a generic chinesium fixture. There is no such company as PLT. PLT is just a house brand for 1000bulbs.com, so you'll never know who made it or what the actual specs are. That's why you see conflicting specs on the webpage and the spec sheet. Also....Power factor is less than 20%??
CD

 

[wyliesdiesels]

It seems to me that you are planning for an incredibly bright shop and then relying on a dimmer to bring it down to a lower level. Don’t you need to run a separate wire to use the 0-10 volt dimmer function for those LED’s?
It seems to me that you could simplify and economize by hanging fewer of those fixtures and also wiring them so that they don’t all have to be on at the same time.

Yes you need separate wires for 10v dimming.

If its piped that isnt too big a deal. If its NM-b, its not so much a big deal either as southwire and other brands make an NM-b cable product that has dimmer wire built into the same jacket with the circuit conductors

 

[shaggyant]

I've read the spec sheet twice, the lack of info and discrepancies would steer me away.

Where is the .99 amps per fixture coming from? They are 100 watt fixtures, 100 watts is .83 amps at 120.

20 fixtures X 100 watts = 1800 watts. 1800 watts ÷ 120 volts = 15 amps.


80% of 20 amps = 16

If they are really .99 amps, they are still under 20 amps. Sure, the lights could be on longer than three hours, but catastrophic failure isn't going to happen. It's no different than plugging a 1500 watt space heater into a 15 amp circuit and leaving it on all night. Breakers can run at the rated load, and a little more, indefinitely. And, if there is a concern, there's nothing wrong with connecting them to 240 volt, which is what the entire thread is about.

I already have the lamps and I can’t return them. I got the .99 amps directly from a sticker on the box and the lamp itself.

PLT didn’t seem like a horrible brand nor 1000 Bulbs a disreputable vendor. At $50 for 14,000 lumens it seemed like a great value.

I’m not gonna lie, I like a lot of light. I want the lighting level of a big box store like Walmart.