More CFL Conversion questions

[Ghetto Wash]

I have a wash with 400 Watt Metal Halide lighting running off 230 Volts.

I want to convert one fixture at a time as they fail to CFL.

The new CFL lamp will fit in the fixture just fine, but it is a 120V lamp. I have two wires running to my fixture, both 120V to ground and 230/240 across them. If I were to convert all fixtures at one time I would just change one of the wires to neutral in the lighting panel or breaker box and wire directly to the lamp socket, but I can't do that if I change one fixture at a time.

Now my crazy idea:
The transformer in the 400 W Metal Halide fixture is a four tap (120V, 230V, 277V, and 460V). I want to toss the capacitor and keep the transformer. I want to rewire the transformer, use my existing incoming power to the fixture and transform it to 120V for the new CFL lamp. I don't know how (or even if possible) to rewire it because I don't know the designed output voltage of this transformer. If I had this designed output voltage I could figure if I could convert my incoming 230V to something close to 120V. As I typed this, I just realized I could get up on the ladder and just measure it - so that's what I'll do.

What do you think? Will it work?

 

[GoBuckeyes]

I have a wash with 400 Watt Metal Halide lighting running off 230 Volts.

I want to convert one fixture at a time as they fail to CFL.

The new CFL lamp will fit in the fixture just fine, but it is a 120V lamp. I have two wires running to my fixture, both 120V to ground and 230/240 across them. If I were to convert all fixtures at one time I would just change one of the wires to neutral in the lighting panel or breaker box and wire directly to the lamp socket, but I can't do that if I change one fixture at a time.

Now my crazy idea:
The transformer in the 400 W Metal Halide fixture is a four tap (120V, 230V, 277V, and 460V). I want to toss the capacitor and keep the transformer. I want to rewire the transformer, use my existing incoming power to the fixture and transform it to 120V for the new CFL lamp. I don't know how (or even if possible) to rewire it because I don't know the designed output voltage of this transformer. If I had this designed output voltage I could figure if I could convert my incoming 230V to something close to 120V. As I typed this, I just realized I could get up on the ladder and just measure it - so that's what I'll do.

Or....strip the fixture of the transformer, forget the 120v cfl and try the 277 volt cfl instead. We had re-wired all our Hubbel wallpacks at one wash to 240v and I was going to use just one hot and the ground but decided to try the 277v bulb..works like a charm. Getting same life out of them as the 120v bulbs I'm using at our other washes.

 

[MEP001]

Are you getting 240V as two 120V legs to the fixture? It isn't to proper electrical code, but you can use a 120V bulb with just one leg and the ground as the common. After you've replaced all the MH bulbs on a circuit you can then run one of the legs as a common.

 

[Ghetto Wash]

GoBuckeyes,
Good idea. As I have 240V into the fixture, those were the lamps I was searching for. There was not a lot to choose from. I didn't think to look for 277V lamps. I'll order a couple of 277V lamps and give it a try.

MEP001,
I had thought of that, but there is no ground wire. Ground is currently through the conduit - I don't know if that's to code either, but that's the way it is.

 

[Kevin James]

Why not do it up right and go with LED conversion kits and you won't have worry about changing the wiring.

 

[MEP001]

MEP001,
I had thought of that, but there is no ground wire. Ground is currently through the conduit - I don't know if that's to code either, but that's the way it is.

Yeah, I wouldn't do that. It is to code like it is, but if anything at all goes wrong the conduit could get electrified if you're using it as a common.

 

[Ghetto Wash]

Why not do it up right and go with LED conversion kits and you won't have worry about changing the wiring.

Because LED conversions are EXPENSIVE. I do plan on doing that with my 320W fixtures as no CFL will fit in them. I am dragging my feet waiting (hoping) the cost of LED comes down.

 

[Earl Weiss]

FWIW One by one I converted my Tunnel 400 W. MH to these.

https://www.kleen-ritecorp.com/p-40744-lsi-legacy-surface-mount-led-light.aspx

The 400 W Fixture lenses weren't that great . The last two I go were the ones linked to. The 4 I got earlier were a prior model and about $50 more and they were great. These are better.

I figured saving 250W per fixture was about 2.5 Cents an Hour or about 30 Cents a day / $100 per year. About a 4 year break even figuring one bulb and Ballast Change saved.