240 volt single phase light wiring

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Old 03-10-10, 05:13 AM
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Question 240 volt single phase light wiring

I am installing a 240 volt single phase fluorescent light. Its a six bulb high bay T8 light with two ballasts. There is no premade plug.

I have connected several of these lights to 110v service but have run into an area in the warehouse where several of the outlets are 240 volt single phase. The light fixtures are dual voltage but I need to wire a plug to the light. I'm using BX armored cable.

Here's the question: I have the right NEMA plug (L6-15P, 15Amp, 250 volt) but I am not sure how wire the plug to the lights. There's a black and white wire connecting to each of the ballasts. The 110 volt connection is simple, black to black, neutral to neutral, and the ground connects to the housing of the light fixture.

How do I connect the light to the plug mentioned above? Do I need to connect the neutral in any way? I have never connected a 240 volt ballast before.

Thanks!
Greg
 
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Old 03-10-10, 10:08 PM
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Are you sure you are working with 240 volts and not 277 volts? There is a definite difference. 277 volt connections involve 1 hot wire and 1 neutral wire and it sounds as if this is what you have. Find the ballasts in the new fixtures and check their input voltage. Most are uni-volt meaning they can be used on either 120 or 277 volt circuits. I have never seen a 240 volt fluorescent ballast.
 
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Old 03-10-10, 11:44 PM
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I have see couple 240 volts flourscent ballast in USA side but in Europe area that is very common item.

However I am pretty sure you are replaceing the old style HID luminaire if so check with the luminaire manufacter to see what they can come up with ballast info if they can order you a 240 volt verison { some case it will need lead time unless you got univseral voltage set up which it will run anything from 120 to 277 volts }

If you tell me what bulb type it is like T-5 or T-8 and I may able dail down to the type of ballast and manufacter.

Merci,Marc
 
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Old 03-11-10, 11:50 AM
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Its a 6 bulb T8 light fixture with a GE 332Max-H/ultra ballast. There are two ballasts.

I too was was surprised it was 240 volt supply. Most of the warehouse is 110v but the breakers for these lights are two pole. I checked the voltage with my meter and got 238v.

We're replacing 400 watt metal halide maybe they needed the higher voltage for these lights?

The light I purchased is rated for 240 volt.

thanks,
Greg
 
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Old 03-11-10, 08:13 PM
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You are right. The GE literature says that ballast will work just fine.

UltraMax™ Ballasts can virtually ‘‘read’’ the incoming
voltage and adapt automatically to any voltage from
108V to 305V.
I'd connect the two hot wires to the black and white ballast leads and ground the fixture with the ground wire.
 
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Old 03-12-10, 05:27 AM
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Basically I would connect it the same way as a 110v connection? Connect the two black leads to the source black wire, do the same with the white wires, and ground it.
 
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Old 03-12-10, 10:05 PM
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The ballast reads the voltage across it's black and white leads. It makes no difference if you have a hot and a neutral or two hots as long as it reads a voltage between 108 and 305.
 
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Old 03-13-10, 02:02 AM
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C'est simple .,,

One black line to black ballast lead then take the other black line to white ballast then green conductor to bare or green wire at the ballast otherwise you have to make sure you have it on the grounding screw this is very important part to get this luminaire function properly.

Merci,Marc
 
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Old 03-18-10, 04:52 AM
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Thank you for all of the help.

Next question. How do you connect the same light for 277 volt?

I assume this is connection is the same a 110v connection. One hot lead, a neutral, and a ground since 277 volt is just one phase of 480 volts?

Thanks!
 
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Old 03-18-10, 06:14 PM
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Oui { yes } it is basic the same as 120 volts system but the conductor colour will be diffrent than what you see on 120 volt system.

Typical they will be Brown , Orange { some case Purple } and Yellow that is the phase colours on 480 volt circuit.

The netural will be Grey colour that is the most common colour but once a while you will see white as well.

Just take the black lead from ballast to hook to the light circuit the white to netural and green to ground.

But one serious warning here with 277 volts they don't have much margin of error on it for one reason they have more than twice the voltage what you see on 120 volts second thing pretty good percentage of 277 volt light circuits are typically wired in MWBC format so if you see two or more phase conductors colours you will have to take a extra step to deal with netural the safest way is turn off the circuit if any other colours there you will have to test it to make sure they are off.

Merci,Marc
 
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Old 03-18-10, 08:08 PM
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Next question. How do you connect the same light for 277 volt?
If the existing circuits are all 240 volt, you won't easily convert your lighting to 277 volt. 277 comes from an entirely different panel and is connected to single pole breakers. The breakers are generally rated at either 480 or 600 volts and are very expensive.
 
 

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