240V lighting??????

[fflintstone]

I might be getting a deal on some 4-lamp troffer lights. I will have to switch out the ballasts for electronic T8 ones. In looking at them online they can work for 120V or 240V.
What is the advantage in 240V?
How are the wired?
How are they switched?

 

[mrb]

how much are you finding 4 lamp T8 ballasts for?

 

[jkeyser14]

The advantage of 240v is lower amperage draw which means smaller gauge wire.

 

[fflintstone]

how much are you finding 4 lamp T8 ballasts for?

$15.49 in the quant. I need. This was just my first search.
I most often go through Amazon

http://www.lightingsupply.com/GE432MAX-N-ULTRA.aspx

Haven’t found much info on the wiring though. I’m waiting for that Charles guy to chime in he seems to have his poo together on electrical questions. I don’t have a clue as to how to switch a 240V circuit do you have to switch both legs? Never done it. as many dryer, stove and welding plugs I have put in I am ashamed to say I don’t know.

 

[fflintstone]

The advantage of 240v is lower amperage draw which means smaller gauge wire.

I noticed that in looking specs, does that increase efficiency?
.85A @ 120V vs. .37A @ 240V

 

[z28toz06]

yes. higher voltage reduces amperage

 

[MattT]

They're probably universal ballasts which will run on foreign Live and Neutral 240v not US Live and Live 220v.

 

[MrMark]

US is 240 volts also. Maybe a little more in most areas.

 

[Charles (in GA)]

They're probably universal ballasts which will run on foreign Live and Neutral 240v not US Live and Live 220v.

Generally there is no 220v in the US, it is all 240v. The ballast could care less if its two opposing phase hots or a hot and an opposing phase neutral, it would not know the difference.

If you wire it for 240v you use a double pole light switch, it has four terminals on it and acts like two light switches in one. (these are NOT the same as a 3 way or 4 way switch) They are found as commercial and industrial, you won't find any spec or contractor grade. HD and Lowes has them, Leviton or Pass and Seymore brands. Of course you have to also use a double pole circuit breaker.

If you do this, I would take a marker or label-er and identify each fixture and box as 240v so if anyone else ever works on them, they understand. I know some 240 or 277v devices (photo cells for yard lights) will not function on a lower voltage once powered on a higher voltage. They actually burn out a resistor or something and would not work on the lower voltage after that, not sure if these ballast would work like that or not.

They do not wire any different, if you use romex, you need to take a red marker and color the ends of the white wire red at every termination so its apparent that the wire is not a neutral, only difference is that instead of running the neutral wire of a 120v circuit directly to the neutral bar in the circuit breaker panelboard, you instead run the wire to the "other" side of the double pole light switch and then from the switch to the "other" side of the double pole circuit breaker.

If this is in a residential building in the US (ie. attached garage) I seem to recall a NEC section that does not allow lighting circuits above 120v, but I haven't looked it up to confirm this.

Edit: I can find references in the code restricting the open circuit voltage of ballasted lighting used in residential to 300 or 1000 depending on the design, but cannot find any other restrictions, so my memory may be faulty.

Second Edit: NEC 210.6 may possibly limit the voltage but I'm not sure I understand it and would need mrb, Norcal, Aceman or another electrical guru on this board to tell me if I'm correct or not.

Charles

 

[Stuart in MN]

Assuming this is a residential application, article 210-6 of the NEC states that the voltage for light fixtures cannot exceed 120vac. In any case there wouldn't be any advantage to running them at 240vac unless you were trying to run a whole bunch of lights on a single circuit.

 

[fflintstone]

If you wire it for 240v you use a double pole light switch, it has four terminals on it and acts like two light switches in one. (these are NOT the same as a 3 way or 4 way switch) They are found as commercial and industrial, you won't find any spec or contractor grade. HD and Lowes has them, Leviton or Pass and Seymore brands. Of course you have to also use a double pole circuit breaker.

Charles

After thinking about it, I figured it was something like this.
I would still like to know if it is more efficient to operate @ 240V.
Otherwise it would not be worth it for the hassle.

 

[Falcon67]

If I had -say- a 24x40 shop with a bunch of 2 bulb "40W" fixtures, I'd run 'em on 240 just to save juice and reduce wire size. The way I light things, that would be ...square root of pi...carry the B52...about 18 fixtures.

 

[Norcal]

If I had -say- a 24x40 shop with a bunch of 2 bulb "40W" fixtures, I'd run 'em on 240 just to save juice and reduce wire size. The way I light things, that would be ...square root of pi...carry the B52...about 18 fixtures.

There are no energy savings by running lights @ 240V, they may have 1/2 the amperes, but it is at twice the voltage so it equals the same.

If residential it's prohibited by the NEC anyway as posted earlier.

 

[scott37300]

Just curious why 240 volt lighting wouldn't be allowed in residential houses/garages?

 

[MattT]

Just curious why 240 volt lighting wouldn't be allowed in residential houses/garages?

Reduced shock hazard probably. 110v ain't no biggie for most folks but 220v will get your attention

The ballast could care less if its two opposing phase hots or a hot and an opposing phase neutral, it would not know the difference.

Charles,

Does this apply to all universal voltage stuff or just ballasts? I always run 90-2xx stuff on 110v in the States just to be safe. Have had a few occasions where it would've been easier to use 220v but I didn't want to risk it.

 

[MrMark]

Just a point of clarification, I'm not totally sure what opposing phases are, but it probably means the two line wires carry two sinusoids that are inverted in polarity and therefore look to be 180 degrees out of phase on a time base. It's called a three wire service and for some strange reason is referred to as single phase although the inverted polarity essentially creates two phases. The neutral is connected to the center tap of the transformer and is tied to the Earth's potential, around 0 v. I do not understand the neutral to carry an opposing phase, rather the neutral, being grounded and serving as a return path for the current, carries the same phase as the phase leg it completes the circuit with.

Since the service neutral carries back to the generation equipment the current flowing on both phase legs for circuits completed through those phase legs it only carries the unbalanced load of those two phase legs as the opposing polarity sinusoids destructively cancel each other out.

Again, the US does not run on 110 v. If you put your voltmeter on your service and you see 110v there is probably a problem.

 

[fflintstone]

There are no energy savings by running lights @ 240V, they may have 1/2 the amperes, but it is at twice the voltage so it equals the same.

It is actually LESS than half the amps for 240V, .85A @ 120 vs. .37A @ 240v (.37 x 2 = .74? ) that’s why I thought they may be more efficient.

 

[Norcal]

Just curious why 240 volt lighting wouldn't be allowed in residential houses/garages?

'Cause NEC 210.6(A) sez you can't.

210.6 Branch-Circuit Voltage Limitations. The nominal
voltage of branch circuits shall not exceed the values permitted
by 210.6(A) through (E).

(A) Occupancy Limitation. 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
(2) Cord-and-plug-connected loads 1440 volt-amperes,
nominal, or less or less than 1⁄4 hp

(B) 120 Volts Between Conductors. Circuits not exceeding
120 volts, nominal, between conductors shall be permitted
to supply the following:

(1) The terminals of lampholders applied within their voltage
ratings
(2) Auxiliary equipment of electric-discharge lamps
(3) Cord-and-plug-connected or permanently connected
utilization equipment

Copy & paste from the 2008 NEC, same as the 2005 edition.

 

[Charles (in GA)]

Just a point of clarification, I'm not totally sure what opposing phases are, but it probably means the two line wires carry two sinusoids that are inverted in polarity and therefore look to be 180 degrees out of phase on a time base. It's called a three wire service and for some strange reason is referred to as single phase although the inverted polarity essentially creates two phases.

That is generally what I am implying, I use the term "opposing phases" rather loosely to get across the point that the alternating current wave forms are 180 out, no matter whether its the other hot, or the neutral.

Most universal ballasts will accept up to 277v as this is quite common in large buildings supplied by three phase, it allows long runs of reasonably sized wires, and lots of lighting on the circuits.

I used Metal Halide light fixtures in my shop that happened to be 120v only, so I ran a switched multi-wire circuit to each fixture location and split a duplex receptacle so it was powered by each side of the hots, then plugged the lights in, alternating them on the A and B sides to even the loads out. Only short runs of neutral between fixtures carries any load. Had my ballast had multi taps, I might have wired them for straight 240v, but it just so happened that the ballast I had were 120v only.

Charles

 

[Charles (in GA)]

Reduced shock hazard probably. 110v ain't no biggie for most folks but 220v will get your attention



Charles,

Does this apply to all universal voltage stuff or just ballasts? I always run 90-2xx stuff on 110v in the States just to be safe. Have had a few occasions where it would've been easier to use 220v but I didn't want to risk it.

I am not aware of any other multi-voltage device that does this, but there could be. The only thing I have run into with that caution was a photo cell for street/yard lights (120v/240v/277v), that was multi-voltage. The instructions cautioned about it not working on lower voltages after being used on higher voltages, as a resistor or something in it would be blown after the first use.

I just brought it up as a point, to make people look carefully at the instructions, etc to see if whatever they have does this also. Might save someone some grief in the future.

Charles

 

[hillbilly1]

I have 277 volt lights in my shop, I have industrial 6 lamp T8- 4' fixtures. Could have changed the ballast, but I have a 5 KVA step up transformer for testing purposes, so it is was economical to just run them off of it.

 

[larry_g]

'Cause NEC 210.6(A) sez you can't.

210.6 Branch-Circuit Voltage Limitations. The nominal
voltage of branch circuits shall not exceed the values permitted
by 210.6(A) through (E).

(A) Occupancy Limitation. 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
(2) Cord-and-plug-connected loads 1440 volt-amperes,
nominal, or less or less than 1⁄4 hp

(B) 120 Volts Between Conductors. Circuits not exceeding
120 volts, nominal, between conductors shall be permitted
to supply the following:

(1) The terminals of lampholders applied within their voltage
ratings
(2) Auxiliary equipment of electric-discharge lamps
(3) Cord-and-plug-connected or permanently connected
utilization equipment

Copy & paste from the 2008 NEC, same as the 2005 edition.

So does this mean that I cannot use 240v to run the HID lights in my disconnected shop? Or is the standalone building with a seperate feed still falling under this rule?

lg
no neat sig line

 

[Charles (in GA)]

So does this mean that I cannot use 240v to run the HID lights in my disconnected shop? Or is the standalone building with a seperate feed still falling under this rule?

lg
no neat sig line

Occupancy Limitation. In dwelling units..........

Only in Dwellings, and as otherwise specified. A fully detached garage is not a dwelling unit (unless you have an apartment in it), so you can run your HID lighting on whatever voltage you wish. (to a point)

NEC 210.6(C) 277 Volts to Ground. Circuits exceeding 120 volts, nominal, between conductors and not exceeding 277 volts, nominal, to ground shall be permitted to supply the following.
(1) Listed electric-discharge luminaires.

Charles

 

[Aceman]

So does this mean that I cannot use 240v to run the HID lights in my disconnected shop? Or is the standalone building with a seperate feed still falling under this rule?

lg
no neat sig line

A shop/garage doesn't meet the definition of a dwelling unit. So if your shop or garage isn't connected to the dwelling unit, then the 120 volt limitation doesn't apply.

 

[fflintstone]

It is actually LESS than half the amps for 240V, .85A @ 120 vs. .37A @ 240v (.37 x 2 = .74? ) that’s why I thought they may be more efficient.

OK now that the code Nazi’s have determined that it is legal to run 240V lighting in a detached shop, can anyone speak definitively as to weather this would be more efficient? Since it draws LESS than half the amps to run them at 240V I would think so, however I am no expert.

 

[hillbilly1]

OK now that the code Nazi’s have determined that it is legal to run 240V lighting in a detached shop, can anyone speak definitively as to weather this would be more efficient? Since it draws LESS than half the amps to run them at 240V I would think so, however I am no expert.

The current is half because the voltage is doubled, you are still using the same amount of electricity either way (wattage). The only real gain would be if you have long wire runs, in which voltage drop is actually wasted energy (heat is created due to the wire resistance and load) You may get a slight gain in ballast efficency (less heating) due to less conversion loss to step up voltage to fire the lamp, but it probably would be very little.

 

[larry_g]

Thanks guys, I just acquired 3 fixtures and wanted to be clear.

lg
no neat sig line

 

[Charles (in GA)]

As already noted, it is twice the volts, and half the amps, equals the same Kwh. I cannot explain why the 240v published amp draw is less than half of the 120v published amp draw. In any case, the difference is minor and you would have to use it for many hours to see any measurable savings in the bill, assuming the published numbers are correct.

You want to see a meter spin real fast? (actually my mechanical one froze up and now I have a remote read digital unit) when I turn on all 6000 watts of metal halide lights and then add nearly 8000 watts of compressor load, plus a couple of flo lights, it runs real fast!!!!!

I don't turn on all the lights very often.

Charles

 

[MrMark]

There may be internal ballasting efficiencies achieved at higher voltages. /There is something in that circuit that works better at 240. Not much there, though.

 

[Grumpy365]

I buy quiet a bit of lighting and i don't think i have ever seen 240 volt lighting ( this would be lighting without a neutral.

I have seen tons of 120 volt
I have seen tons of 277 volt ( 1 leg of 460 with w neutral)
I have seen tons of multi tap or universal ballast ( all that need a neutral)

But never 240 volt. Can someone list a link to a cut sheet?

 

[hillbilly1]

I buy quiet a bit of lighting and i don't think i have ever seen 240 volt lighting ( this would be lighting without a neutral.

I have seen tons of 120 volt
I have seen tons of 277 volt ( 1 leg of 460 with w neutral)
I have seen tons of multi tap or universal ballast ( all that need a neutral)

But never 240 volt. Can someone list a link to a cut sheet?

Before the advent of electronic ballasts, Magnetic Hid ballasts with multi-taps, gave the choice of 120,208,240,277 and sometimes 480 volts. The new electronic ballasts automatically adapt to the voltage they are connected to. The most common use in the states is 120 or 277 volts.

 

[mrb]

one might use 240v where the service is 240 3 wire delta, you would operate the lighting at 240v to reduce the size of your 240D-280Y120 transformer.

 

[Grumpy365]

one might use 240v where the service is 240 3 wire delta, you would operate the lighting at 240v to reduce the size of your 240D-280Y120 transformer.

I just asked my electrical supply house, and they didn't know of any 240 volt light readily available in the states ( i grant you the guy i was talking to was not the sharpest guy at the counter)

I would use the heck out of a 240 volt light if i could find one.

 

[fefarms]

I use Lithonia 4 tube 8 foot T8 striplights in my shop. They come with "MVOLT" ballasts, which can be run off 120/208/240/277 volts. I run them off 240 volts to reduce the total amount of wire required and to gain a (very slight) efficiency. I control them in two banks using two two-pole lighting contactors mounted in the attic space. This allows the lights to be controlled from three different locations in the shop using low current control wiring instead of sending all the supply current through 3-way/4-way switches and 200 feet of travelers

 

[Stuart in MN]

But never 240 volt. Can someone list a link to a cut sheet?

Here's a light fixture I was just looking up yesterday that's available in 240 volts: http://www.acuitybrandslighting.com/library/LL/documents/PSG/WST.pdf

As other people have mentioned, nowadays it's typical for light fixtures to come with multivolt ballasts, if nothing else it makes it easier for the electricial supply houses since they only have to keep one kind in stock.

 

[malibu101]

I just asked my electrical supply house, and they didn't know of any 240 volt light readily available in the states ( i grant you the guy i was talking to was not the sharpest guy at the counter)

I would use the heck out of a 240 volt light if i could find one.

We use Sylvania ballasts at work for (2) f32t8 lamps. They are labeled as 120-277VAC. We wished to use them on 240V, meaning no neutral.
Called Sylvania tech (1-800-lightbulb) they gave their blessing to use them at 240V.
It's been a few years and they are working fine.

 

[fflintstone]

I use Lithonia 4 tube 8 foot T8 striplights in my shop. They come with "MVOLT" ballasts, which can be run off 120/208/240/277 volts. I run them off 240 volts to reduce the total amount of wire required and to gain a (very slight) efficiency. I control them in two banks using two two-pole lighting contactors mounted in the attic space. This allows the lights to be controlled from three different locations in the shop using low current control wiring instead of sending all the supply current through 3-way/4-way switches and 200 feet of travelers

This seams like a great way to wire them if going the 240V route.
Do you have any info on the 2 pole lighting contactor you used?

 

[timgr]

Why would you want to wire 240V to lights? There's so much 120V commodity-grade stuff that's cheap and plentiful, and you aren't drawing enough current to make the wire size matter. A 120V/15A circuit will power a lot of fluorescent bulbs. Just because you can run these ballasts at 240V doesn't mean that you should.

If you're worried about the ballast's efficiency, I suggest you look around for another 120V-only ballast with a higher efficiency rating.

 

[Grumpy365]

We use Sylvania ballasts at work for (2) f32t8 lamps. They are labeled as 120-277VAC. We wished to use them on 240V, meaning no neutral.
Called Sylvania tech (1-800-lightbulb) they gave their blessing to use them at 240V.
It's been a few years and they are working fine.

I guess i learned something new. I would have bet that it would let the factory smoke out in short order.

What did you hook up the white wire on the balast to? ( the second leg of your 240?)

 

[Charles (in GA)]

I guess i learned something new. I would have bet that it would let the factory smoke out in short order.

What did you hook up the white wire on the balast to? ( the second leg of your 240?)

Yep.

Charles