Bad maintenance practices tend to sneak into the way things get done. Here are three more to guard against:
Bad Practice #20 — Covering Only "Critical" Breakers in Your Circuit Breaker Testing Program.
While critical breakers may warrant "more attention," other breakers don't merit "no attention." Whether an 800A breaker supplies critical production machinery or a lighting feeder, it can cause massive damage through arc-faulting or interrupt operations through nuisance trips.
Bad Practice #21 — Not Updating Maintenance Test Values to Correspond to Values Established by the Most Recent Coordination Study.
Often, such a study is a response to an unnecessarily wide area of shutdown. The purpose of the study is to set all breakers to values that prevent this problem. You don't want techs to defeat this by using outdated test specs.
Bad Practice #22 — Limiting Breaker Maintenance to Functional Testing
Where training is inadequate, this is often what happens. The tech doesn't know the other things to look for with that particular breaker model or breakers in general. Develop checklists that present the myriad ways to spot potential issues.
