gsport
Well-known member
i'm about to get 8 400 watt bulbs and fixtures (110 volt) for my shop.. they came out of a warehouse... my question is: how many can i put on one 20 amp circuit??..
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400 watt shop bulbs...
- Thread starter gsport
- Start date
Charles (in GA)
Well-known member
If these are high bay lights, you probably won't be happy with them. If you have 14 ft ceilings, then the bottom of the light will hang at about 12 ft. Way too low for a light designed to be 20 ft and up. You will end up with bright "hot" spots and shadows in between.
You don't say how big your shop is, or the shape, dimensions, etc. of it.
The 400 watt metal halides I have draw about 480 total watts and run 3.8 to 4.0 amps on 120v (tested with a clamp amp meter). All are identical Lithonia part numbers, but about half were made in Mexico and draw the lower amps, average about 3.8, while those made in the Illinois factory draw right at 4.0 amps. Do not know why the difference.
If these are sodium or mercury vapor, just sell them and go find something else.
Here is the thread on my lighting installation.
http://www.garagejournal.com/forum/showthread.php?t=21048
Charles
You don't say how big your shop is, or the shape, dimensions, etc. of it.
The 400 watt metal halides I have draw about 480 total watts and run 3.8 to 4.0 amps on 120v (tested with a clamp amp meter). All are identical Lithonia part numbers, but about half were made in Mexico and draw the lower amps, average about 3.8, while those made in the Illinois factory draw right at 4.0 amps. Do not know why the difference.
If these are sodium or mercury vapor, just sell them and go find something else.
Here is the thread on my lighting installation.
http://www.garagejournal.com/forum/showthread.php?t=21048
Charles
nadogail
Well-known member
Be careful about making sure the voltage you have to work is one of the options your ballasts can use. In my experience 120 volt Metal Hallide lighting has been rarely used.
nice write up charles on your lighting thread.. my shop is 45x60 with 14' walls and a peak of about 19'.. the lights didn't cost me anything. i did some trading and actually made a few dollars too.... they are listed as drawing 4 amps... what i'm replacing are four individual flouresent fixtures that dont' put out much light at all. each are on a plug, so i'll just unplug the flouresent lights and plug in the 400 watt MH lights
Be careful about making sure the voltage you have to work is one of the options your ballasts can use. In my experience 120 volt Metal Hallide lighting has been rarely used.
the guy i'm getting them from brought one over to see if i wanted them. he had already rewired it for 110 volts... seems to be ok, we'll see when i get the rest, probably this weekend
Advance or magnetek replacement ballasts that I've installed are 4.7 amps, I wouldn't load it more than 3 although I've seens lots of aplications where there are 4.I just looked at the spec sheet for a RAB 400w metal halide low bay, 4 amps @ 120v, so based on that -4 fixtures per circuit.
sberry
Banned
Sometimes a 30A circuit is used for that type of lighting.
Charles (in GA)
Well-known member
I wired mine on 3 different Edison Multiwire circuits. I pulled both hots and a neutral, split the tabs on the hot side of the duplex receptacles and pigtailed each receptacle (necessary by code on multiwire), used three 30amp double pole light switches (bought on clearance), labeled each half of the receptacle for which side of the circuit it was on, with a large red A and a large black B. 4 receptacles on each double pole common trip circuit breaker. I plugged in the lights alternating, A B A B. The fixtures I have were 120v ONLY and had come from one of several Sams or Walmarts in the Atlanta area that were converted to T8 fluorescents.
Charles
Charles
I wired mine on 3 different Edison Multiwire circuits. I pulled both hots and a neutral, split the tabs on the hot side of the duplex receptacles and pigtailed each receptacle (necessary by code on multiwire), used three 30amp double pole light switches (bought on clearance), labeled each half of the receptacle for which side of the circuit it was on, with a large red A and a large black B. 4 receptacles on each double pole common trip circuit breaker. I plugged in the lights alternating, A B A B. The fixtures I have were 120v ONLY and had come from one of several Sams or Walmarts in the Atlanta area that were converted to T8 fluorescents.
Charles
you mention 30a switches, did you use them because you got them cheap or did you run 30a circuits?
Charles (in GA)
Well-known member
As noted, got them on a clearance. Home Depot often looks at inventory and if they have too much of something, it gets marked down temporarily to get the inventory down. These were Pass and Seymour and I paid about $4 each for them, thats cheap for 30 amp DP light switches.
I used 20 amp DP common trip breakers and 12 gauge wire.
Charles
I used 20 amp DP common trip breakers and 12 gauge wire.
Charles
As noted, got them on a clearance. Home Depot often looks at inventory and if they have too much of something, it gets marked down temporarily to get the inventory down. These were Pass and Seymour and I paid about $4 each for them, thats cheap for 30 amp DP light switches.
I used 20 amp DP common trip breakers and 12 gauge wire.
Charles
nice, thats a great deal for those switches. They will last alot longer than a 20amp switch with 1600 watts of ballast load on it.
Charles (in GA)
Well-known member
A couple of mine buzz also, kinda annoying, but after a while, it just becomes background noise, until you turn it off and realize how loud it is.
Charles
Charles