Just a little fact that is often ignored...
The MV manufacturers almost ALWAYS reccomend the bulb be placed straight down, not at an angle. So don't use clamp lamps, unless you're planning on clamping them into a straight down position.
I think this may be the cause of much of the early failures of these bulbs.
Most MV bulbs are cheap, but the heavy ballasts are usually very expensive, and weigh several pounds. MV bulbs last an extraordinarily long time. The problem is in the miniaturized ballasts in the reptile lights. They are SOOOO tiny and delicate. The slightest bump and they fail.
My father has a MV security light outside of his shop, it goes on as soon as it gets dark--for a good 3-4 years straight. it's about a 200W bulb, too. The ballast is the key, it's huge.
My MV bulbs broke yesterday. I was putting my old wall hanging cage up, and I put the bulb on top. As I was getting ready to put branches and plants in, the whole cage (4 feet tall, 2 feet deep, and 3 feet wide) fell from its mount--apparantly, I has missed the stud--oops. The MV bulb fell from the top, about 6.5 feet up in the air, and hit the ground. The bulb was fine, but I think the ballast was shot. When I tried to see if it still worked, the circuit breaker flipped---twice.
I needed to put the cage back up, as my veild wasn't secure in the other one. This way, I have the ENTIRE 12'X3' wall area for the deremensis group.
I'll send some pics soon, I got a nice digital camera for christmas.
What kind/wattage bulb do you have? That may matter when it comes to positioning.
