Converting 120 to 240?

[BioHazard]

I'm replacing my old 120v magnetic ballast fluorescents with new 120-277v Sylvania electronic ballasts. Right now the 20 amp circuit is nearly maxed out, the new lights are much more efficient, but I want to add more of them too.

Obviously the lights have a 12/2 run with ground. Can I simply move the neutral wire to a double pole breaker with the other wire, and color each end red with some heat shrink tubing? ****, 240v?

 

[oleguy]

n0.the 120/277 means that in commercial/industrial use you can use 277 derived from a high leg of a 480 3 phase.the high leg of a 480 3 phase gets 277 from one phase leg to a neutral on 4 wire delta.will try to get you a drawing.

 

[oleguy]

this will help

 

[BioHazard]

These are electronic ballasts, they only have two input wires, they work on whatever you give them, anything from 120 to 277v, automatically.

 

[oleguy]

if it say's 120 to 277 then ok if you make sure it isn't over loaded.if it is marked 120/277 ans is still no.

 

[Charles (in GA)]

Indeed the new electronic ballast work on any voltage without any changes to the ballast. It should work OK on 240 volt. You can do what you are suggesting except you need to insure that NOTHING else is on the circuit, and depending on how the switch is installed, you may have some rewiring to do. Since 240 is two hots, you need to interrupt with the switch, both sides of the circuit. As it stands now, the switch only interrupts the hot side, and the neutral (grounded conductor) is not switched as there is no need for it. The switch would turn the circuit on and off OK, but there is an inherent danger in having that un-switched hot on all the time. You would need to run both hots to a double pole light switch and then run both wires on to the light fixtures.

Charles

 

[ddawg16]

I'm replacing my old 120v magnetic ballast fluorescents with new 120-277v Sylvania electronic ballasts. Right now the 20 amp circuit is nearly maxed out, the new lights are much more efficient...

I really don't think you are going to see any real difference in efficency on the new lights running them on 220. Yes, the new electronic ones will be more efficient than your old magnetic....but the total wattage at 120 or 277 is going to be pretty much the same....the only thing different will be the actual current draw....

So, if your wanting to run them on 220 thinking it's more efficient....it's not.....unless I missed that electronics course...

 

[Identaltech]

^^^^^ I think he's trying to get more lights to the same circuit.
switching it to 240 from 120 will cut his amps in half. IE he could double the amount of light on the same circuit.
Yes his power usage IE watts will remain about the same.
voltage x current = watts

 

[oleguy]

Indeed the new electronic ballast work on any voltage without any changes to the ballast. It should work OK on 240 volt. You can do what you are suggesting except you need to insure that NOTHING else is on the circuit, and depending on how the switch is installed, you may have some rewiring to do. Since 240 is two hots, you need to interrupt with the switch, both sides of the circuit. As it stands now, the switch only interrupts the hot side, and the neutral (grounded conductor) is not switched as there is no need for it. The switch would turn the circuit on and off OK, but there is an inherent danger in having that un-switched hot on all the time. You would need to run both hots to a double pole light switch and then run both wires on to the light fixtures.

Charles

thanks charles.did not think of other devices on same ckt. mike.

 

[mrb]

it wont be any more efficient (watts is watts) but you will be able to get twice as many fixtures on the circuit. You need to make sure NOTHING else is on there, and that no other circuit is stealing a neutral from this one.

 

[Norcal]

If this is residential, forget about anything higher then 120 volts,NEC article 210.6(A) prohibits what you want to do......

Here is a copy & paste from the 2008 NEC.

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

This is unchanged from the 2005 edition.

 

[W-Cummins]

n0.the 120/277 means that in commercial/industrial use you can use 277 derived from a high leg of a 480 3 phase.the high leg of a 480 3 phase gets 277 from one phase leg to a neutral on 4 wire delta.will try to get you a drawing.

Well.....

That is not the way you get a 277V to ground on your service. The center grounded 480V delta service you show will have a "high leg" but it's 415.68V to ground not 277v the other legs are 240V to ground and in the US. is not of any use. The only reason to install such a service would be to clear ground faults (this type of service is very rare). The corner grounded 480V delta is more common, but not wide spread either. The common way to get 277v to ground is a 4 wire 480v wye system.....

William....

 

[Aceman]

I'm replacing my old 120v magnetic ballast fluorescents with new 120-277v Sylvania electronic ballasts. Right now the 20 amp circuit is nearly maxed out, the new lights are much more efficient, but I want to add more of them too.

Are you're switching to T8's?

If this is residential, forget about anything higher then 120 volts,NEC article 210.6(A) prohibits what you want to do......

Here is a copy & paste from the 2008 NEC.

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

This is unchanged from the 2005 edition.

What does this article have to do with lights in a garage/shop?

 

[Justanoldguy]

Way to confusing for me.
Here in New Zealand everything is 240 volt.
Unless it's 3 phase of course.
We don't have 120 volt power supply.

 

[Norcal]

Are you're switching to T8's?



What does this article have to do with lights in a garage/shop?

If residential EVERYTHING!

 

[Justanoldguy]

Way to confusing for me.
Here in New Zealand everything is 240 volt.
Unless it's 3 phase of course.
We don't have 120 volt power supply.

 

[MrMark]

Looks like it applies. Dwelling, one family, is defined as a building that consists of one dwelling unit. Dwelling unit is thus the whole building where the family lives, cooks, eats, etc. Attached garage is part of the building. If detatched different story.

 

[oleguy]

Well.....

That is not the way you get a 277V to ground on your service. The center grounded 480V delta service you show will have a "high leg" but it's 415.68V to ground not 277v the other legs are 240V to ground and in the US. is not of any use. The only reason to install such a service would be to clear ground faults (this type of service is very rare). The corner grounded 480V delta is more common, but not wide spread either. The common way to get 277v to ground is a 4 wire 480v wye system.....

William....

yep.was thinking 120,240.208.delta

 

[Aceman]

If residential EVERYTHING!

Is that how you read it?

I read it as nothing above 120v in a home, I don't see anything about garages or shops. Do you consider a garage a dwelling unit?

 

[Norcal]

Is that how you read it?

I read it as nothing above 120v in a home, I don't see anything about garages or shops. Do you consider a garage a dwelling unit?

A garage is part of a dwelling. If it attached to your home on a residential property or a detached shop is not zoned as a commercial enterprise then your only allowed 120 volts for lighting.

 

[DURAMAT]

LOL

I highly doubt anyone here has 3 phase 277/480 primary then with a step down transformer for 120/208 in their Home or in the garage out back behind their home.

Them 120/277 ballasts are made for either 120 or 277 applications only. if you want 240V then your gonna have to decide between a HPS or Metal Halide with a multi tap ballast. Nothing wrong with it unless you say the word "Dude" alot and are growing "Herbs for the local Herb store" . LOL

If you want more lights,,run another circuit plain and simple

 

[W-Cummins]

LOL

I highly doubt anyone here has 3 phase 277/480 primary then with a step down transformer for 120/208 in their Home or in the garage out back behind their home.

Doubting Duramat yee of little faith, that would be incorrect!

William....

 

[DURAMAT]

Just because Home Depot has the word "Home" don't count! LOL

 

[Falcon67]

Is that how you read it?

I read it as nothing above 120v in a home, I don't see anything about garages or shops. Do you consider a garage a dwelling unit?

Depends on how much "domestic" trouble you may be in.

 

[Norcal]

LOL

I highly doubt anyone here has 3 phase 277/480 primary then with a step down transformer for 120/208 in their Home or in the garage out back behind their home.

Them 120/277 ballasts are made for either 120 or 277 applications only. if you want 240V then your gonna have to decide between a HPS or Metal Halide with a multi tap ballast. Nothing wrong with it unless you say the word "Dude" alot and are growing "Herbs for the local Herb store" . LOL

If you want more lights,,run another circuit plain and simple

Those electronic ballasts are 120-277 V so they can be run on 120 through 277V., only problem I see is 120 & 277V are line to neutral & 208 & 240V are line to line supplies....

But I agree totally w/ the last comment....

 

[Charles (in GA)]

... or a detached shop is not zoned as a commercial enterprise then your only allowed 120 volts for lighting.

(A) Occupancy Limitation. In dwelling units.................

I think one can easily argue that what you are asserting is incorrect. The code refers to units, a detached garage is not a dwelling unit, the code uses similar wording in other places. I think the code intends you to apply it according to use, not zoning, and to individual structures not everything located on a parcel of property.

I also agree, the best course of action is to run more circuits.

Charles

 

[Friartuck]

Need to read that code section carefully. It applies to 15 Amp circuits only (hence the reference to 1440 volt-amperes). Other subsections (for greater than 15 amps) do permit 220-240 volt. Think about it, there are 220 volt sockets for window type air conditioners and four prong oven plugs. Those are both in a dwelling. Wiring these at 220volt is not a code violation. The intent of subsection Part a) is to prevent 220 Volt to be available for general lighting or general appliances (meant to run on 110V).

Are there double pole double throw for commercial (wall switch) lighting??
As Charles mentioned, need to switch both hots, not just one leg of a 220 line. You could use the breaker as the switch.

 

[BioHazard]

LOL, I thought this would be a one answer thread. This is in a detached building. Right now my lights draw about 16.5 amps, which I believe violates the "80% maximum" rule. The new lights are significantly more efficient, to replace the same amount of light I could probably cut that down to around 10 amps, BUT, I also want MORE light.

Run a new circuit? Sure, that's easy to say for free from behind your computer, and yeah, it would be great in an ideal world. That's basically what I want to do here - abandon the old "120v" lighting circut, and barrow the old wires to "run a new" 240v circuit. Now I'm only burning 5 amps up to maybe 10 max. I believe the least amps in a given wire is usually the best option. Actually I could probably downgrade the 20A breaker to a DP 15A.

Now the issue I see here is the switch. I didn't think I had to turn off both hots, why is that? I know they make double pole light switches, but, I also know every regular light switch I've ever seen is marked 120-277v like my lights. I'll have to look inside the switch box, the neutral wire might already be in there capped off. I know in my old shop I had 400w 240v metal halide fixtures with a switch that only cut one hot wire. Maybe it was done wrong to begin with?

I guess I could just use the breaker as the switch....

 

[BioHazard]

Here in New Zealand everything is 240 volt.

But aren't you worried all those 240v lights are going to set your bedrooms on fire?!

 

[Justanoldguy]

But aren't you worried all those 240v lights are going to set your bedrooms on fire?!

Well in the last 160 years of power in New Zealand I don't recall 240 volt lights being the cause of too many fires.

 

[Friartuck]

For a 220 volt circuit, both hots have to be disconnected. You cannot have one of the 220 lines as a common/neutral like is done with a 110 V circuit. The common/neutral is at 0 volts.

Only double pole switch I can think of for 220 V is the seperate box with the lever on the side that is in reality a knife switch inside. Disconnect boxes like that are used for larger water pumps or hot tubs.


Added:
And apparently there are Leviton 120/277 volt double pole wall switches.

 

[1Garageman]

Are you telling me that you don't have anything that runs off of 120v?
I don't just me tools and things in the garage, but TV's, hair dryers, regular lights, etc...
I am curious.

 

[oleguy]

For a 220 volt circuit, both hots have to be disconnected. You cannot have one of the 220 lines as a common/neutral like is done with a 110 V circuit. The common/neutral is at 0 volts.

Only double pole switch I can think of for 220 V is the seperate box with the lever on the side that is in reality a knife switch inside. Disconnect boxes like that are used for larger water pumps or hot tubs.

leviton makes 20 amp snap switches.use those all the time for mastercool evap coolers.

 

[Friartuck]

oleguy is right. Leviton makes 120/277 volt double pole wall switches. Learn something new every day.

 

[Falcon67]

>Are you telling me that you don't have anything that runs off of 120v?

Down under power (and most of the rest of the world - US/Canada is "special"):
Electrical Power and Phone Specifications in Australia

Voltage (230 Volts): ​

International AC outlet adapters do not convert electric current. If your appliance does not accept 220-240 volt current, serious damage can result if you do not also use astep down transformer to convert the current to 110-120 volts. Step down transformers convert 220/240 volt electricity to 110/120 volts for American appliances. ​

Frequency (50Hz): ​

North American 110-120 volt electricity is generated at 60 Hz (cycles). Most international 220-240 volt electricity is generated at 50 Hz (cycles). This difference in cycles may cause the motor in your 60 Hz North American appliance to operate slightly slower when used on 50 Hz. Please note that many 60Hz devices such as clocks may not function normally on 50Hz current.​

 

[Justanoldguy]

Are you telling me that you don't have anything that runs off of 120v?
I don't just me tools and things in the garage, but TV's, hair dryers, regular lights, etc...
I am curious.

No 120v stuff at all.
Everything including all appliances etc are 240v

 

[Charles (in GA)]

Are you telling me that you don't have anything that runs off of 120v?
I don't just me tools and things in the garage, but TV's, hair dryers, regular lights, etc...
I am curious.

I know it may come as a surprise, but virtually all of the rest of the world uses 240 volts as their primary voltage. Canada, the US, Mexico, Central America, parts of South America, Taiwan, and Saudia Arabia are the only countries that use the "split" 120v/240v system. Follow the link for a world map and descriptions of various voltages and receptacles used worldwide.

http://users.telenet.be/worldstandards/electricity.htm

Charles

 

[Charles (in GA)]

leviton makes 20 amp snap switches.use those all the time for mastercool evap coolers.

I used three Pass and Seymour double pole "snap switches" (ie. light switches) to control my three multi-wire lighting circuits.

Charles

 

[nehog]

I know it may come as a surprise, but virtually all of the rest of the world uses 240 volts as their primary voltage. Canada, the US, Mexico, Central America, parts of South America, Taiwan, and Saudia Arabia are the only countries that use the "split" 120v/240v system. Follow the link for a world map and descriptions of various voltages and receptacles used worldwide.

http://users.telenet.be/worldstandards/electricity.htm

Charles

Two more bits of trivia... (and I've lived in both the US 120 volt world, and the 240 standard as well...)

1. It has been proven that 240 is actually safer than 120 volts from a shock/electrocution standpoint. It turns out that it is harder to grab a 240 volt line, your hand gets knocked away first.

2. Japan uses a 100 volt standard, just to be incredibly different!

3. Having experienced both systems, I'd actually prefer the 240 volt only standard, it is easier to work with, no need for load balancing, etc.

 

[DURAMAT]

I'm cofused, how is it safer? You have two legs that are 120 of opposing phases. If one don't get ya say hello to it's buddy that will? LOL