Motor shaft grounding can enhance reliability in your inverter-fed motor

摘要

Variable frequency drives, as useful as they are for saving energy in many applications, may cause premature motor failure without proper grounding. Consider this: As a typical maintenance engineer attends to the regularly scheduled points of interest on the top of the typical commercial building or industrial plant, the days go by re-greasing motors and checking for other signs of fatigue. Without preventive maintenance tools or advanced predictive control software to provide an alarm, the engineer may stop and think, "Are those motors getting louder, or is it just my imagination?" The experienced engineer's internal sensors (hearing) and hunch (predictive alarm) may be correct. Over time the bearings have been experiencing premature wear without anyone being aware, but why?