480 Volt Lighting

landeselectric

21 lights, 480 volt controlled through a lighting contactor a 120 volt coil. The contactor and coil were working correctly sending 480 volts to lighting. Checked all neutral connections and all power connections. No problems were found. But the lights will still not come on. Ballast and bulbs are fine. What could be the problem?

Speedy Petey

Wow. Are you sure there is 480 to the load side terminations of the contactor? Maybe the contactor is not pulling in all the way? Maybe something is stuck inside or the coil is weak and not pulling it in all the way.

What neutral are you checking? To the coil? The lights should not have a neutral at 480v.

Are you reading 480v right at the fixtures themselves?

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frenchsparky

i have to ask this question here is the system is true 480 volts ??

you have to mesure from line to line to verify it other wise if line to netrual it will read 277 volts.

one warning here be extra carefull with 480 volts you don't get much leeway with this system at all.

if this is on HID [ high instendy discharge] lamps did you check the ballast sometime some of them have capaitor in series with bulb circuit if go bad either will be dim or refused to light up [ i will explain more in seprate details later]

i know some contractors can get "hung up" so kill the power to the contractor and recheck the concat button to make sure it is not pitted or hevey burn mark on them.

is the contractor to handle all this lighting load or have few circuits along the way ??

let us know

Merci , Marc

firemike

You said you checked all the "neutrals"... That would lead me to believe that the lights are 277 volt. Have you actually checked for voltage up at the light, right where it connects to the ballast? Is it a multi-tap ballast? If so, is it set to the right voltage? Did you check contact continuity at the contactor (with the power off) to make sure tha contacts are actually closing?

RobertWilber

It doesn't matter what voltage the lights are
As long as you have the PROPER voltage, it doesn't matter whether the lights are 480 volt or 48 volt.
You are sounding panicky, so I guess you don't do a lot of 480 work...
You will have the same problems you have at 120 volts
wrong voltage tap selected
open circuit
bad contactor
all the same old gremlins
I take it none of the lights have lit since the job was installed ...
Make SURE what voltage you are getting at the lights
Make SURE they are tapped at the right voltage
Check all components for proper installation [if one got done wrong, they are probably all wrong the same way ...]
keep at it
you'll find it
good luck

RobertWilber

forgot to ask...
do the ballasts and lamp type match?
HPS and MH don't play well with others

Bkessler

My luck it would be a loose wirenut. ABC apprentices. Enough said.........go wings!

wildwood

hey dude, your question is a good one but it is after 1am and i need to get up at 630am. if i get a chance tomorrow, i will reply with a couple of ideas and tips. remember though - troubleshooting is a process of elimination, working from the most obvious to the least obvious. good luck and i'll try to respond tomorrow. ak

wavector

Are the ballasts tapped for 480 volts? Bypass the lighting contactor if they are and see.