Question on 400w MH mounting and wiring...

[snydes]

Hi guys. I recently picked up 10 used multi-tap 400w metal halides for my shop. Unfortunately they did not come with the mounting hooks. I have found some sources for the cable/hook ranging from $10-$13 depending on type of plug, does that sound high? Right now I am thinking of only running two to a switch. As far as wiring them either for 110 or 220, what would be better and why?

Thanks,
Steve

 

[rockwithjason]

If you use 220 you can put more lights on one circuit. You should be able to run 3 or 4 on one 120v 20a circuit depending on the ballast current rating. You might be able to run all 4 on one double pole switch if you use 220v. As far as mounting, there are a whole pile of ways you could do that so without specifics it will be hard to help on that one.

 

[snydes]

I have a iron framed steel building, so I figured on putting eye bolts in the purlins and hanging them from the hooks. Unfortunately the hooks were not included with these lights (they are used) and so I am shopping around for the hooks. I found a place that sells just the hook for $4.50, and a few other places that sells the hook with cable for between $10-$15, I didn't know if that was high or not.

Thanks,
Steve

 

[Aceman]

That's probably about right. We always install low bays with a cord and twistlock plug for ease of servicing. Then all you have to do is unplug it and take it down to the ground to work on it. If you look at the ballast rating for the given voltages then you can determine how many per circuit. You'll want to keep it at 16 amps or less on a 20 amp circuit. I figure you'll end up using 3 circuits if 120v and 2 circuits if 240v.

 

[Charles (in GA)]

Indeed, 240v will allow twice as many lights on a circuit as 120v does. 400w MH in 120v will draw 4 amp, and 2 amp at 240v. Of course, with 240v you have to use a double pole handle tied circuit breaker, and you must use a double pole switch that interrupts both sides of the circuit as they are both hots.

Charles

 

[snydes]

Thanks, that clears things up as far as the wiring goes.

Steve