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#177857 - 05/13/08 09:47 PM Metal halide light tripping  
schenimann  Offline
Member
Joined: Feb 2008
Posts: 193
Western North Carolina
I went on a service call yesterday. In a store downtown, a lady had a 250 watt metal halide light that would trip off then come back on. The breaker never trips, only the light. It would do this once, maybe twice a day, sometimes not at all. It is a fairly new fixture, isn't in a location where it would build up excessive heat and it is a 250w ballast.

The outlet that it is plugged into was originally a 220 outlet converted to a 110. Whoever had worked on it previously had used one of the hots and the ground as a neutral. Our fix was to use the other hot as a neutral and yes, we did go to every jbox we could trace and mark it neutral. Would using the ground as a neutral cause the light to trip? If not, what else?


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#177859 - 05/13/08 10:03 PM Re: Metal halide light tripping [Re: schenimann]  
sparkyinak  Offline
Member
Joined: Jul 2007
Posts: 1,317
Alaska
Bad bulbs. HPS does the same thing


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#177860 - 05/13/08 10:33 PM Re: Metal halide light tripping [Re: sparkyinak]  
twh  Offline
Member
Joined: Mar 2004
Posts: 905
Regina, Sask.
I agree a bad HPS bulb will cycle. I'm not sure about MH bulbs. I thought I saw it last week, but when I suggested a new bulb, the carpenters were all over me. They had already tracked it down to voltage drop when another piece of equipment started. Now, I don't think I've seen an MH bulb do that.


#177861 - 05/13/08 11:26 PM Re: Metal halide light tripping [Re: twh]  
renosteinke  Offline
Cat Servant
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Joined: Jan 2005
Posts: 5,316
Blue Collar Country
You probably had a high resistance ground ... this had the effect of lowering the voltage .... not enough volts, bulb would try to re-strike.


#177862 - 05/13/08 11:28 PM Re: Metal halide light tripping [Re: renosteinke]  
schenimann  Offline
Member
Joined: Feb 2008
Posts: 193
Western North Carolina
Should fixing the neutral fix this?



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