METAL HALIDE FIXTURE FAILURES
Metal halide lamps (bulbs) have a unique, and many times, costly charactor trait about them which is, a very definite life usage span. This is usually given in hours used. Most manufacturers will state in their specifications for any given metal halide lamp its life expectancy. Metal halide lamps should be replaced at their life expectancy interval, regardless of how well they might appear to be operating. When metal halide lamps are used past their life expectancy they can start to draw more current than the transformer feeding them is capable of handling. This will cause the transformer to overheat and fail. This also can damage the capacitor, another vital element in the ballast of the metal halide fixture.
Property owners whose buildings and parking lots are illuminated by metal halide light fixtures are urged to pay attention to this life expectancy and set up a program where all the lamps are replaced together at the end of their life expectancy. This takes some dedication but ultimately it will result in less costly fixture repairs.
These two transformers are identical. The one on the left came out of a metal halide fixture where the lamp had been used for much longer than its life expectancy, causing the transformer to heat up and fail.
These two capacitors are identical. The one on the right came out of a metal halide fixture where the lamp had been used for much longer than its life expectancy, causing the capacitor to heat up and fail.