Changing 120v lighting to 240v

[clare]

Correct, Don.

[Iowna Uass]

A 100 watt load would consume half the current if you double the voltage. However where I come from, you can't "paint the white red", you need to separate the ground and common. Therefore the need to run either 2 14/2 wires or a 14/3.

[keith]

If all you have is 240V loads you don't need a common (neutral). If you do, "painting the white, red" doesn't help. You have some idiots (likely union electricians) running your local government.

[Don Klipstein]

240V incandescents produce less light than 120V ones of the same warrage and life expectancy, due to economies of scale having to do with the diameter of the filament.

There are other exemptions to the upcoming USA incandescent lamp ban. One is incandescents that meet a certain energy efficiency standard, and they do exist (but they are not widespread). For example, there is the Philips Halogena "Energy saver" 70 watt, which produces 1600 lumens - nearly "full 100 watt equivalence". Home Depot has them.

Reflectorized floodlight and spotlight bulbs are also exempt from the upcoming ban. There are even a few Philips Halogena "Energy Saver" ones.

[clare]

If done the way you are saying, the switch MUST be a double pole switch - otherwise one line is always HOT (both lines are HOT with the switch on)

[keith]

Well, duh! How is this any different than any other 240V circuit, three-conductor or otherwise?

[clare]

Just means the entire system NEEDS to be rewired to use 240 lighting

[clare]

LOTS of low voltage halogen fixtures around with the transformers on them. Lots of separate low voltage lighting transformers around too. Stick with magnetics instead of electronic (switch mode supplies) to avoid EMI problems..

You could very easily make up a plug-in transformer that you plug the lamp into.

see:

for information on one major manufacturer's line.

[krw]

The entire circuit, obviously. As long as the "white" wire is in each box it's not a big deal. It's *exactly* the same issue whether or not painting the white, red, is permissible.

[clare]

The white wire needs to be at ground potential, and on a norh american system, running 240 volts, NEITHER wire is at ground potential - so the wires need to be black and red. No white wire required - and BOTH lines need to be switched

[Nate Nagel]

It's standard practice to use 2-wire (with ground) cable for pure 240V circuits (e.g. water heater, air conditioner) and to simply reidentify the white as a hot at each box with a ring of black or red tape. Now if you are pulling THHN in pipe it would make sense to pull red and black, but I'm not aware of special 240V romex with red/black or other non-white, non-grey, non-green colors.

nate

[krw]

Yes, you've still added nothing to the discussion. In a purely 240V circuit there is NO NEED for the white wire. See the part about painting the white wire red. This is very common and outside of some areas, evidently, where union thugs run things, is perfectly acceptable.

- so the wires need to be black and red.

No, they really need to be anything other than green (or green/yellow) and white. See the part about painting the white wire red.

...and now you're agreeing with me that you've added nothing to the conversation.

[krw]

Right. Other than three conductor cable, neither have I.

[jw]

Let me guess, you live in Florida? CFL bulbs work fine if the winter temps dont get below freezing (32 deg.F). But try using them in the northern states where the winter temps stay at zero for weeks, and can drop as low as MINUS 40 deg. F At that extreme low, NO FLORESCENT BULBS WILL WORK.

[clare]

Except for SAFETY reasons, on a north american system which is NOT strictly 240, neither line is "dead. BOTH are LIVE. Live lines need to be switched.- and identified.

So OK - not white or green - but switched.

[clare]

I'll stand by my contention that for applications where 120 volt incandescents will not be available and flourescents are not viable, low voltage incandescent is the simplest, safest, and most adviseable way to go, when compared to changing to 240 volts for lighting circuits in north american residential situations.

It has been done for several decades in very wide-spread applications including reading lamps, floor lamps, track lighting, task lighting, and indirect lighting. Both indoor and outdoor, and emergency lighting as well. Both halogen and standard tungsten bulbs have been widely used for these applications and all the parts or assemblies you would ever need are commonly available, off the shelf, with both UL and CSA certifications as required.

Duck soup? Who knows - not nearly as messy.

[Roy]

=3D=3D Not true. I have two cfl perimeter lights that are switched on every night 365 days of the year. They take a bit longer to light when cold but they do work even when switched on when it is -40. One just has to give them time to light. both perimeter lights are in glass enclosures as in a porch light and I haven't tried bare bulbs outside as it is not recommended and very likely wet snow would cause them to break. =3D=3D

[trader4]

I'd like to see a reference in the NEC where it says both sides of a

240V circuit need to be switched. It's true for circuit breakers, but switches? I would personally want to switch both sides, but is it an absolute requirement? I was recently looking at a buying a solar pool pump controller that was UL listed. It was designed to control a 240V pool pump and it only switched one leg to turn it on and off via a single pole relay. Would seem strange if the code says you can't do it.

[clare]

I didn't say the NEC required it. I said irt is required "for SAFETY reasons" Anyone who would do it any other way is a fool - pure and simple. PARTICULARLY in a lighting circuit - where NOBODY is expecting a "live neutral" and 240 volts. We are talking lethal power here, where things are done according to a STANDARD to make it safe, although not idiot proof. Deviating from that standard adds multiple significant risks.

You do it however you want in your own home, and make sure your liability insurance is up to date if you or your family/survivors/whatever ever have to have someone other than you work on the system after you are gone.

[dpb]

[e-mail] wrote: ...

Don't see a reference to the Code section but my Wiring Simplified Handbook says each leg must be switched if neither is grounded. This is quite old so would seem to have been in Code a long time. While the book isn't particularly concerned in identifying chapter/verse, it isn't prone to saying things that aren't so...

The specific paragraph in the book says

"Double-pole switches are required by the Code when neither of the two wires is grounded. In practice this means you must use double-pole switches for 240 Volt motors or appliances."

Whether there are other exceptions or not I can't say.