Car Lot MH lamps buring out

[chrisb]

I have a customer that is a new car dealer. They have perhaps 100 to 150 MH shoe box fixtures mounted on 30' poles operating on 208 Volts. My contact at the dealership (not a technical person) is a bit frustrated with the number of bulbs that burn out. He had another electrician changing the bulbs but has hired me to look into the problem a little deeper and to replace bulbs and general electrical work. I assume one of two things; first, the bulbs are lasting per manufacturers warrantee and he's just not keeping accurate records. Time does fly. Or, he has a power condition problem of some kind.

What would you recommend as first steps. Also, are power companies of much help in these instances?

If I need to check the condition of the power, can you suggest a power conditioner that works well and won't break the bank account. Buy or Rent?

Thanks - Chris

 

[barbeer]

Sometimes a POCO will leave a register tape machine that records power related events to see if they have any problems. I would start there other than the obvious tests, sounds like you are on the right track. Sometimes a new lamp will last for a while, but if the ballast is bad or going it will pre-maturely burn out a lamp. Good luck

 

[don_resqcapt19]

Are the correct lamps being used? Some MH lamps have a required orientation and others are universal?
Don

 

[chrisb]

On Monday I'll be removing the first bulbs and look for this.

 

[jinglis]

When you pull the lamps out have a look at the sockets. A burnt socket will only destroy a new lamp in quick order. Perhaps starting a tracking sheet to determine which lamps were changed when will help determine lamp life.

 

[emahler]

my first guess...with 100-150 fixtures, they are only changing the lamps that are out. original installation lasted +/-2yrs, then some when out, so they changed them. since then, it's just been a constant flow of lamps going out and being replaced.

label the poles and track the lamps. they probably keep thinking its the same fixtures since "it's the lamp over there"

 

[chris kennedy]

Probably not an issue, but I would check for voltage drop at the ballast while I'm up there just to rule that out.

 

[peter d]

Most cheap probe-start MH lamps are only rated 10-15,000 hours. And as others have pointed out, this will decline if the specified burning position is altered in any way.

 

[don_resqcapt19]

It is also interesting to note that the listed life of a lamp is the number of hours for 50% of the test lamps to fail.
Don

 

[W6SJK]

It is also interesting to note that the listed life of a lamp is the number of hours for 50% of the test lamps to fail.
Don

[edit] i.e. it's a median life expectancy.

 

[chrisb]

Thanks everyone. Went up on the lift today and changed out 11 lamps. 2 bulbs were already shattered in the fixtures. I replaced the bulbs with Sylvania lamps and I need to go back and replace some ballast. I didn't have them on hand today so we went to complete what we could. My local distributor had them for $175.00 but that seems way high. Do you agree?

What are your opinions of Sola ballasts and Pluslite lamps? I noticed them from an Internet-based distributor. I'm always a little skeptical when it's not Philips, GE, Sylvania, etc.

Thanks - Chris

 

[peter d]

2 bulbs were already shattered in the fixtures.

That is a very solid indication that these lamps have been operating way past their rated life.

I would try to sell them on changing all the lamps. Remember that with all HID lighting, particularly MH, light output declines dramatically as burning hours increase. So although the customer is paying the same amount on their electric bill, they are getting less and less light as these lamps approach their rated life. And it only gets worse from there, and lamps start to violently fail as you have discovered.

 

[cowboyjwc]

I tend to agree with the general thought that the bulbs are just simply burning out.

I did facility manintenance for 7 years. The boss got mad one day because of all the relamp work orders and told us to replace every burnt out lamp we found. 20 cases of tubes later we were done. A week after that he wanted to know why we hadn't done as we were told as there were lights out all over the plant.

I tend to replace all of the bulbs in the my chandaliers at once and of course when they start to go out......