I'm the maintenance electrician at a hospital and we have a big problem with the outside parking lot lights. every time we run the generator test with the hospital load, we burn out from 20 to 30 HiD 400w Metal Halide bulbs. And sometimes when the power utility company has problems with their transformers, the samething happens. is there something i can do to prevent this from keep happening. we do have a 6amp fuse on the bottom of the pole, do you think it will be better if we had smaller amperage on the circuits.?
blowing at least 20 MiD 400w bulbs a month.
- Thread starter HF24983
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How exactly are the bulbs failing? Do they just try to light several times or do the arc tubes burst or turn black?
Have you checked and/or changed the ignitors in the affected fixtures?
Is it the same fixtures that fail each time or is it random?
Are these lights on 24/7? If so that is a big part of the problem as MH and other arc luminares are supposed to have some off time to protect the lamps.
Don't think changing the fuse sizes would help much if at all.
Have you checked and/or changed the ignitors in the affected fixtures?
Is it the same fixtures that fail each time or is it random?
Are these lights on 24/7? If so that is a big part of the problem as MH and other arc luminares are supposed to have some off time to protect the lamps.
Don't think changing the fuse sizes would help much if at all.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
What is the output on the genny. Is it possibe the genny is putting out too much voltage.
I don't think the fuse will help.
I don't think the fuse will help.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Or under possibly? Similar effect?
Me neither.
I have plenty of HID MH lights from 175w to 400w that work off gennys just fine.
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
I have not seen an igniter in a 400w MH. Most of the pole lighting I do is 175w to 1500w and there is no igniter. Ballast, cap and bulb only in what I work on.
The smaller stuff 100w and lower has these. What exactly are they? Start vs run caps? I need to look this up.
hillbilly1
Senior Member
- Location
- North Georgia mountains
- Occupation
- Owner/electrical contractor
mcclary's electrical
Senior Member
- Location
- VA
I'm not 100% sure, but I think lower voltage is not hard on them, it's the high voltage that hurts them. It seems with incandescents, you can use a 130 volt bulb and they last along time. I could be wrong for comparing that to a MH.
dbuckley
Senior Member
- Location
- Canterbury, New Zealand
I would also suggest checking the voltage as the first step
Just as a thought - are these lights switched daily or do they burn 24/7 except for gentests?
Just as a thought - are these lights switched daily or do they burn 24/7 except for gentests?
jumper
Senior Member
- Location
- 3 Hr 2 Min from Winged Horses
Could be a pulse start, they have ignitors.
Thanks, did not know that.
Please do not feel insulted, but I have to ask, are you giving the lamps sufficient time to cool off so they can re-light before you assume that they are bad? Alot of times I'll have 1 or 2 that won't re-light but I've never seen 20. This happens more on lights that are on 24/7 which I assume your pole lights are not.
Article 90.1
Senior Member
Time do do a month long PQA IMHO. I think the "blown" lamps are a symptom of a larger problem. I assume that you are changing these lamps weekly if it is a hospital, your gen. tests run weekly, right? Anyone check the output frequency of the genny. lately?
I love these kinds of puzzles, there is ALWAYS a cause, but finding it (them) is the fun part of our trade. Please do keep us updated so we can learn from this situation too.
One last thought, Is the genny. in the vicinity of the affected light poles? Perhaps there is excessive vibration being transferred through the poles. I can imagine that a small vibration at the base of a 30' pole would be amplified several times once the wave reaches the top of the pole.
I love these kinds of puzzles, there is ALWAYS a cause, but finding it (them) is the fun part of our trade. Please do keep us updated so we can learn from this situation too.
One last thought, Is the genny. in the vicinity of the affected light poles? Perhaps there is excessive vibration being transferred through the poles. I can imagine that a small vibration at the base of a 30' pole would be amplified several times once the wave reaches the top of the pole.
You will need to gather a lot of info--voltage, watts, manufacturer, pulse start or probe start, any other info, wire size, etc.
Call the ballast and lamp manufacturer and ask for tech support.
I had a situation where GE 1000W MH lamps were melting in the socket of the luminaire.
The lamp rep came out, went up in the 65' bucket truck and looked at the socket, ballast, and wiring.
When we got down, he said "Tough SHCookies" GE lamp XXXX ballast. Then he said, If I was you I would get new sockets NOT made by XXXX.
That solved the problem. Apparently the company that made the lamp sockets had a bad batch. He was able to identify that by the date on the fixture.
Good luck.
Call the ballast and lamp manufacturer and ask for tech support.
I had a situation where GE 1000W MH lamps were melting in the socket of the luminaire.
The lamp rep came out, went up in the 65' bucket truck and looked at the socket, ballast, and wiring.
When we got down, he said "Tough SHCookies" GE lamp XXXX ballast. Then he said, If I was you I would get new sockets NOT made by XXXX.
That solved the problem. Apparently the company that made the lamp sockets had a bad batch. He was able to identify that by the date on the fixture.
Good luck.
Hi HF
I've had a similiar situation. I have several dozen parking lot lights on the campus here and they are also on my genny. I was noticing the same bulb failure in my poles. I put my fluke recording meter on the outgoing power to record a min/max. Instead of the 208 volts like I was supposed to see I was seeing between 200 and 700 volts. Now I had a bigger problem. I got a hold of the genny rep and he got with the transfer switch rep and between the two of them came up with inductive switch bounce as the cause. Long story short the xfer switch guy gave me a new switch which is better suited to carry the kinds of loads which I have on the genny.
Don't know if this will help ya or not, but I would put some recording equipment on that outgoing generator power and make absolute sure the problem is there, rather that out in the parking lot. Modern HPS bulbs are very robust and can take some "dirty" power. They will not however take several restarts over a short time and really hate to be over-voltaged.
Keep us all posted man
Steve
I've had a similiar situation. I have several dozen parking lot lights on the campus here and they are also on my genny. I was noticing the same bulb failure in my poles. I put my fluke recording meter on the outgoing power to record a min/max. Instead of the 208 volts like I was supposed to see I was seeing between 200 and 700 volts. Now I had a bigger problem. I got a hold of the genny rep and he got with the transfer switch rep and between the two of them came up with inductive switch bounce as the cause. Long story short the xfer switch guy gave me a new switch which is better suited to carry the kinds of loads which I have on the genny.
Don't know if this will help ya or not, but I would put some recording equipment on that outgoing generator power and make absolute sure the problem is there, rather that out in the parking lot. Modern HPS bulbs are very robust and can take some "dirty" power. They will not however take several restarts over a short time and really hate to be over-voltaged.
Keep us all posted man
Steve
LeeB
Member
- Location
- California
Blowing HID Lamps on Gen Test
Blowing HID Lamps on Gen Test
From your statement that there is a fuse at the base of the pole, I'm assuming you have either 120v or 277v supply to the fixtures. I wonder if you are losing the neutral momentarily during transition, resulting in 208v or 480v supplying the fixtures thus blowing the lamps.
LeeB
Blowing HID Lamps on Gen Test
From your statement that there is a fuse at the base of the pole, I'm assuming you have either 120v or 277v supply to the fixtures. I wonder if you are losing the neutral momentarily during transition, resulting in 208v or 480v supplying the fixtures thus blowing the lamps.
LeeB
Az Streetlights
Member
A couple of thoughts: Are your lamps universal mount? Or mount sensative. You did not say whether the fuses blow, or not. MH lamps do have to have some down time to allow the metal gases to re-collect on the emitter. 6 amps seems reasonable to me for the fusing. AZ Streetlights
turdsandwich101
New member
I would check voltage first. Possibly could have dropped the neutral at the generator.
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