120V emergency lights with 208V lighting? Overcurrent device?

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donw

Senior Member
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Arizona
I have an application where I'd like to specify 208V low bay MH lights, but I notice that "bug eyes" only come in 120V or 277V. Do you see anything wrong with placing the 120V bug eyes on one unswitched, ungrounded conductor of the normal 208V lighting, as long as I show a neutral to the bug eyes, as well? It seems that 240.20 would allow this with any tied or multi-pole breaker with internal common trip.

Another option I've thought about would be to run a single 120V circuit (from the same panel) to all the emergency fixtures and have a lock-on device per 700.12(F) exception. There are 4 normal lighting circuits in the same room.
 
I think I'd probably just run a 120V circuit and put somthing like a QO1LO on the handle of the breaker. Saves a lot of confusion.
 
donw said:
I'd like to specify 208V low bay MH lights, but I notice that "bug eyes" only come in 120V or 277V. Do you see anything wrong with placing the 120V bug eyes on one unswitched, ungrounded conductor of the normal 208V lighting, as long as I show a neutral to the bug eyes, as well?
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By Bug Eyes do you mean photocells?

Are you saying here that you want to have two ungrounded conductors (208v) and use a photocell to break only one of them?

If so, we just had this conversation and the reason you can't do that, in a nutshell, is:

jerm said:
if you hooked it up that way you'd be in violation of 2005 410.54 (B) or 2008 410.93. You have to switch both ungrounded wires.
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jerm said:
By Bug Eyes do you mean photocells?
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"bug eyes" is the slang term for these:

daymaker.gif


I stole this image too
 
I can't even specify bug eyes anymore. Every project I work on I have to submit emergency lighting calculations to the AHJ at time of final inspection. These little fixtures have trouble getting the 1fc average and 40:1 max:min ratio.

I usually end up adding a few fluorescent fixtures in between the HID fixtures. Add a battery pack or two to each fixture and switch them with the HID fixtures. When you turn on the lights in the morning there's a little light from the fluorescent while you're waiting for the HID lamps to warm up. You'd also be able to use 208V for all of the lighting in this situation.
 
Mr. Bill, what do you do about restrike? I use the bug eyes because I can find them with restrike timers. Can you find emergency fluorescent ballasts with restrike timers?
 
I'm not sure what you mean by restrike timer. Is this similar to the quartz restrike in an HID fixture that's on a generator?

The fluorescent are on when ever the HID are on. There's no timer. Just the battery pack that gets installed next to the ballast.
 
Ooops! I see what you mean. The fluorescents would kick back on (assuming the switch is on) immediately after a brown out. I am using bug eyes that have a timer built in, so they stay on up to 10 minutes after power is re-applied.
 
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