Hey guy im having some problems..I installed 44 ha lts in a local chevy dealership. They are about 16 by 16 in square, about 9 in deep. They all have a capasitor and a ballast. Well the problem is almost everyone have had caps changed about 30 percent have had new ballasts. They all have multi tap ballasts , were are using 120 volts the farthest away from the panel is about 60 feet. We have even took ko"s out thinking it might let some heat out , we have also checked for voltage drop... Can someone help we do alot for this dealer they have 5 car lots they baught the fixtures but its costing them a fortune in service work to replace bulbs, ballasts,capasitors....

Are you using the right lamps?I have installed veritical burn units and horizontal burn lamps by accident and had problems.I try just to use universal burn lamps now.Well that's the only idea I got for ya anyhow.

honestly, could just be bad fixtures. One of our customers has about 12 facilities, all built by different contractors. Well, one facility in particular has a really bad High Bay fixture. There are about 90 in the building and in the 5 yrs since they built it, we've changed out about 55 ballasts. These things fry. Burnt to a crisp. The, for some reason, are wired 120V (should have been 208V imho- no 480/277V available)

But we have good voltage at all of them. Good connections. I will say this, this facility is also the only one that uses plug in GE panels. All the rest are bolt-on's of various brands. I'm leaning towards there being some irregularity that we can't catch due to the cb's. it's just a theory.

I know this isn't much help, but it might just be a bad batch (manufacturer) of fixtures.

Did you contact the manufacturer? If these fixtures are a constant problem, there's always the possibility that they have been installed in a manner they were not designed for. A simple oversight, such as proximity to the ceiling, too much load on a single circuit, (the possibiliteis are endless), etc., could be causing the fixtures to eat components. They could also contain a design flaw that the manufacturer has already come up with a quick fix for, and they can give you the run-down on that.

The other problems I run into alot are voltage fluctuations or other problems with the supply power (i.e. high harmonics), and heat.

Voltage fluctuations tax a ballasts more than you might imagine. Too high or too low voltage both have an effect on the coils and the caps.

Heat is always a problem too, but mostly for the ballasts. Once the enameled coil windings get too hot and start breaking down the enamel insulation, the ballast is done-for. Is there any ventalation around the ballast? Is the ballast too close to the bulb and not shielded? These are all things to look for...

Good Luck!