Help wiring split circuit fluorescent fixture

[DanielVetpath]

I am using four bulb (4') T5 HO light fixtures from Lithonia (IBZ454) in my shop. 16 fixtures arranged in 8 pairs. I was planning on switching them in pairs to avoid turning them all on at once If I don't need a lot of light. Prepping for some garage time over the holidays, I opened the back of one light to check wiring to find four wires: one each of green, black, red, and white. A sticker notes "Standard factory wiring is for all on - For switching operation connect red wire to a switched input." I called lithonia and the rep said I can run two or all four bulbs - a bonus considering my goals of varying the amount of light at a given time. My question is how to do it (Lithonia rep said ask an electrician)? Run white from input to fixture; pigtail black to two switches and run hot from one switch to black and one hot from the other switch to red on the fixture? Use separate switches or a paired/double switch? Thanks for any help. Daniel

 

[rvcoaster]

why not run a simple MWBC to all lights and use two circuits?

 

[Steevo]

MWBC=Multi-Wire Branch Circuit
Dual-Pole Breaker and wired with two hots, a neutral and a ground, so 14/3 for your lights (if using romex), running to switch location, each hot through a separate switch (could be dual switches in single slot) , continuing to fixture, where one switched hot goes to black wire on ballast and the other hot to the red wire on ballast. Neutral to white and ground green, and viola, each switch controls 2 bulbs on the fixture.

 

[DanielVetpath]

So....I should run separate hots to both the black and the red on the ballast for separate switching. Presumably, if both wire-nutted together, all four would light at the same time.

 

[Steevo]

So....I should run separate hots to both the black and the red on the ballast for separate switching. Presumably, if both wire-nutted together, all four would light at the same time.

Presumably . . .

 

[Highbeam]

Couldn't you do this by running a normal 12/2 to the switches and feed both switches from the one black hotwire. From there go to 12/3 and attach one switch output to the black and the other output to the red? Why use up two breaker slots?

 

[SixStringMadness]

you don't need to use two breaker slots if you use light switches. Run a 12/2 to the switch, then a 12/3 to the lights. It's like wiring a fan with a light where the two can be controlled independently with two wall switches as opposed to the pull chain.

One switch will operate the black wire, the other the red wire. One hot coming from the breaker to the switch box, two going out the the lights

 

[Charles (in GA)]

why not run a simple MWBC to all lights and use two circuits?

If those are the ballast I think they are............


You cannot supply them with a MWBC

The ballast has a caution on it that they must be supplied off the same buss.

Do NOT pigtail the black to the two switches, run the black to one of the switches, and from there a pig tail to the second switch and ALSO to the black on the ballast. The second switch (which is supplied from the first) supplies the red.

These pics are from a T5HO ballast in a 8 ft, 4 bulb (pairs in tandem) LITHONIA strip fixture from Home Depot.

HERE IS THE THREAD where these were discussed.

Charles

 

[SixStringMadness]

If those are the ballast I think they are............


You cannot supply them with a MWBC

The ballast has a caution on it that they must be supplied off the same buss.

Do NOT pigtail the black to the two switches, run the black to one of the switches, and from there a pig tail to the second switch and ALSO to the black on the ballast. The second switch (which is supplied from the first) supplies the red.





These pics are from a T5HO ballast in a 8 ft, 4 bulb (pairs in tandem) LITHONIA strip fixture from Home Depot.

HERE IS THE THREAD where these were discussed.

Charles

This makes a lot of sense. I'm not personally familiar with this ballast, but I understand what he is explaining and agree.

 

[DanielVetpath]

Just a follow-up on my particular Lithonia IBZ454 lights/ballasts I originally posted about. They don't have a warning label regarding use of same vs. different buss strips. I wired one up just to see how the lights worked and found that power needed to be to black always. Black only - two bulbs, Black and Red - all four bulbs; red only - no light. So....I went with double pole double pole switches recommended by Charles (in GA) to avoid visitors throwing one half of a double switch (i.e. the red side) and not having any lights (e.g. If I used a double switch like kind for bathroom fan and light, you would have to know which one to turn on first). With the DPDT switches, you might get all 4 instead of only two lights, but anyone will have some light come on. Thanks for all the help and input. Daniel

 

[SixStringMadness]

With the test you describe, switch one will feed the black wire one the ballast and also the second switch. The second switch will feed the red wire. If second switch is on, with first switch off, no lights, no problem, because if switch one is off, no power to switch two anyways, so no power is even going to red wire until switch one is on with switch two.

Make sense?