Blowing out PAR 36s left and right....
Good morning -
In the fall of 2010, we installed a 30+ fixture system for a very good client. The system is comprised of 3 transformers, roughly 14 well lights (PAR 36), and the remainder are MR16 bullets and path lighting. The PAR 36 fixtures have never been right; I've been through about 30 bulbs now (for being old headlights, these things aint cheap as most of you know....). Each time I get the system up and running again and replace the fixtures, they all test at 10.6 -11.6 volts. Then, they start blowing within 2-3 days. The prob is mostly on two transformers, one especially.
The loading on it goes like this:
Transformer 1 (300W), run 1 - 13V tap (on circuit 1), 3 lamps, 11V, 11.3V, 11V
Transformer 1 (300W), run 2 - 13V tap (on circuit 2), 3 lamps, 11V, 11.1V, 11.2V
Again, it's always the well lights - everything else is fine. I have installed good, GE bulbs. All wiring is 12 ga, and connections are silicone nuts. One thing - because the fixtures have been moved / bulbs changed so often, the wiring where it meets the lamp is worn and probably not clean - not sure this could be causing burnouts so quickly though.
So, I'm at the end of my rope on this one - any thoughts on what might be happening? My feeling at this point is that it's fluctuations in primary voltage, but how the heck do you prove that... I have toyed around with getting some direct burial voltage regulators just to see if that fixes it. If it does, then primary voltage is likely the problem.
Thanks for your help