Mercury vapor (or other) security light

[kellyjones1]

Anyone know anything about MV lights? I have an old (10-20 yr) security light outside my barn, wired to come on at night. It hasn't worked since I bought the place, ~7 years ago.

I got up on a ladder yesterday and noticed the fixture buzzing when power was applied, just barely audible. I replaced the bulb (and placed a bucket over the photocell, and waited for nightfall) and still no light. So I'm guessing the ballast is shot. However, doing a quick search online, h39 ballast seems to go for $60 up! And that's not even for the correct form factor. Somehow I don't think repairing this is going to be the most cost-effective approach to getting some work light.

Any suggestions for fixing/repairing this? Is there a better/cheaper technology (halogens, e.g.)? What's the advantage of MV lighting used, anyway? SInce I'll only use this a couple hours a week at most, energy efficiency isn't high on the list of priorities.

(By the way, I know I'll get flamed if I don't add this, so: I don't have any intention to leave this on 24/7, or even 12/7. It will be on a switch, and I'll turn it on when I need some temporary work light in this location - the entrance to my barn. I don't need always-on lighting, and I don't intend to contribute to light pollution.)

Thanks,

Kelly

[Manster]

I have 2 of the old mercs as well. Change the photocell. It should twist and unplug. Mine run less than $10. I have large side yards with plenty of good nighttime 'hiding' places so I figure the mercs are cheap insurance. A necessary evil if you will.

[RBM]

If it's buzzing, the power is passing through the photocell. It's probably a bad ballast or igniter and not worth repairing

[Big_Jake]

The photocell could be shot too, but you should look at replacing it with a Sodium Vapor light. Same amount of light with about half the electricity.

JK

[alvinamorey]

I'd change the photocell anyhow. I have a complete fixture as a spare that I keep in the garage. I replace piece by piece in the garage. I hate being up on that pole. When I get one piece that dont work on the ground, I know thats the problem. Referring to photocell and bulb. I never had to replace a ballast.

$60 for a ballast is rediculous. I bought a complete fixture with bulb, mounting pipe & bracket for around $35. That was a few years ago, but I bet they are not much over $40. Of course it depends on where you buy them. (Just by chance did you get a defective NEW bulb)? It can happen. Thats why I like my tests on the ground.

As for replacements, halogens have problems with bad sockets after a few years, and then they eat bulbs. Personally, if it was only for temporary use, I'd just install a common indecesant 150W flood or two bulbs. But for an all night yard light, that is not as cost effective as far as power use. I never tried a sodium light. I dont like the color.

PS. when the light buzzes, turn it off, then back on again. They can do odd things at times......

[John Grabowski]

Personally I think mercury vapor lights are outdated technology. I never liked the fact that the bulbs don't burn out. They just get progressively dimmer with age. Metal halide is more efficient as is high pressure sodium. For maximum lumens per watt there is always low pressure sodium, but you may have a difficult time finding cheap fixtures.

Here is one link to some reasonably priced fixtures. There are many more links out there if you do a search.

[alvinamorey]

While I will agree they do get dimmer with age, I disagree about them not burning out. I have had several of them just that quit working one day. Most were getting dim before they died, but I had at least one that was still bright and suddenly died.

[Don Klipstein]

They do eventually burn out. Eventually. And now they're making them cheaper, and they don't last like they used to.

Most effectively efficient lighting for outdoors at night among these is metal halide. Lumens aren't all the same when things are dim enough for scotopic vision to make a significant contribution to sensation of illumination. Furthermore, sodium light (both low and high pressure, excepting shorter life lower efficiency higher cost higher color rendering index HPS) tends to make reds, greens, blues and purples darker. Low pressure sodium has the ultimate bad color rendition - everything is an orange-yellow version of black-and-white.

- Don Klipstein ( [e-mail])

[Dan Lanciani]

| $60 for a ballast is rediculous.

Doesn't the 2005 EPAct ban the manufacture/import of mercury lamp ballasts as of 1/1/2008? That might explain a price spike...

Dan Lanciani ddl@danlan.*com