Over the past year or so, complaints about the light levels in the manufacturing areas have been increasing. The lamps are metal-halide. The last relamping was a couple of years ago, so the cause can’t be that the lamps are approaching their end of life.
The production superintendent met with a lighting consultant who recommended a complete redesign of the lighting system. But the fact that the consultant wanted the redesign job and the fact that the lighting was deemed sufficient for many years has you wary about this recommendation.
Now the pressure is on to fix this problem. How should you proceed?
Many things can cause lighting levels to deteriorate. First, see if they actually have deteriorated. Conduct a new lighting survey, comparing readings to the baseline light readings from the original installation. Perhaps the light is just as good, but the work locations have moved in relation to the lamps.
Check for mechanical issues. Take light readings before adjustments and again 2 hr after:
· Lamp lenses are dirty.
· Shades are misadjusted.
· Fixtures aren’t aimed properly.
Check for electrical issues. Take light readings before and after any repairs. Use a power analyzer to look for:
· Low line voltage.
· Low power factor.
· Unbalanced phase loading.
· Sinewave distortions.
What if you find low line voltage? Perform load calculations to see if the relevant transformers can support the connected load. If you don’t find an overloaded transformer, perform insulation resistance and leakage tests on the relevant conductors.
