Burning Lamps

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jerjwillelec

Senior Member
Location
Nevada, IA
The city municipality I do work for owns a couple acre sports park with walking/running trails throughout. There are about 50 lights serving these trails. 175 watt MH, approximately 10 years old, fed and controlled from 4 different sources, most at 277 volt...some might be 208, I'd have to check. They run from dusk until around midnight and again from 4:00ish until dawn everyday. Here recently, within the last two years, they are replacing lamps like none other. They just replaced them all last October and 90%+ need replaced again. Any ideas based on your experience as to why this is? I checked random poles and the voltage serving the ballast is 285+/- volt and ballast to lamp is 280 volt. It can get very windy out there and was wondering if that may have an effect on a gas lamp (didn't think so but I'm out of ideas). Any ideas?
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
Cheap bulbs can always be a culprit. I avoid brands like SLI and go for well known like Sylvania. Also is the rated burning position correct?
 

mbrooke

Batteries Included
Location
United States
Occupation
Technician
Metal Halide lamps are position sensitive, in the least burning them horizontally shortens life and increases end of life arc tube rupture by a small degree. There is base up, base down, universal, horizontal and position orientated horizontal. The bulb should be rated for the actually burning position.
 

gadfly56

Senior Member
Location
New Jersey
Occupation
Professional Engineer, Fire & Life Safety
The city municipality I do work for owns a couple acre sports park with walking/running trails throughout. There are about 50 lights serving these trails. 175 watt MH, approximately 10 years old, fed and controlled from 4 different sources, most at 277 volt...some might be 208, I'd have to check. They run from dusk until around midnight and again from 4:00ish until dawn everyday. Here recently, within the last two years, they are replacing lamps like none other. They just replaced them all last October and 90%+ need replaced again. Any ideas based on your experience as to why this is? I checked random poles and the voltage serving the ballast is 285+/- volt and ballast to lamp is 280 volt. It can get very windy out there and was wondering if that may have an effect on a gas lamp (didn't think so but I'm out of ideas). Any ideas?

The one thing it sounds like they haven't replaced are the ballasts. Maybe some common EOL failure mode is causing them to eat lamps?
 

cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
The one thing it sounds like they haven't replaced are the ballasts. Maybe some common EOL failure mode is causing them to eat lamps?
That was my first thought. My other question is you said that they were getting power from four different sources and yet a random check gave you 285 volts or so. On all of them? or was that an average? You also said that it was 277 volts or maybe 208. Probably better to check the voltage at the base and see what you're getting there. A neutral problem could be the problem also, but if you have power from three different sources it's either at the main service if there is one or on the utility side.
 

jerjwillelec

Senior Member
Location
Nevada, IA
That was my first thought. My other question is you said that they were getting power from four different sources and yet a random check gave you 285 volts or so. On all of them? or was that an average? You also said that it was 277 volts or maybe 208. Probably better to check the voltage at the base and see what you're getting there. A neutral problem could be the problem also, but if you have power from three different sources it's either at the main service if there is one or on the utility side.

They're 277 volt. I just couldn't remember if one specific set was 208 or not. As said, my checks were random but at each location were getting what we should be at the bottom and top

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jerjwillelec

Senior Member
Location
Nevada, IA
One thing I think I failed to mention: the parking lot lights as well as the baseball, softball and soccer lights don't have the same issues. Granted, they're not on near as much. Just leads me to believe the electrical system is ok and the lamps are the problem...

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cowboyjwc

Moderator
Staff member
Location
Simi Valley, CA
One thing I think I failed to mention: the parking lot lights as well as the baseball, softball and soccer lights don't have the same issues. Granted, they're not on near as much. Just leads me to believe the electrical system is ok and the lamps are the problem...

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Could be. Used to really upset me to get a bad batch of bulbs, because as electricians that's never really our first thought.

They're 277 volt. I just couldn't remember if one specific set was 208 or not. As said, my checks were random but at each location were getting what we should be at the bottom and top

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:thumbsup:
 

Rampage_Rick

Senior Member
Have you verified that they're turning on and off at those times? Had some MH bulbs fail relatively quickly because the photocell had died and they were burning 24/7. I remember seeing an article that a 24/7 burn will result in a shorter lifespan than a 23 hour burn with 1h cooldown.
 
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