Suppose a lighting ballast fails. Replacing it is usually a complete repair, but such a failure should rarely occur. How do you know if this is a “one-off” or a symptom of a root cause that needs attention? One key is to track all failures in your CMMS and periodically analyze accumulated data for repair frequency by type of failure.

The likely root cause of chronic ballast failure is poor power quality. Don't confuse power quality with harmonics (harmonics is a subset of power quality). Your harmonics analyzer may show no problems while ballasts are blowing due to periodic or sustained voltage sags, overvoltage, or alternating sags and surges.

In our next issue, we'll discuss what to do at the service panel to eliminate a recurring repair cost.