Troubleshoot AC Motors – Part 4

Posted 3/29/2004

Problem D – Motor bearings run hot or noisy

D1: Check loading. Is excessive side pressure, end loading or vibration overloading bearings? Reduce overloading.* Install larger motor.
D2: Is sleeve bearing motor mounted on a slant causing end thrust? Mount horizontally* or install ball bearing motor.
D3: Is bent or misaligned shaft overloading bearings? Replace bent shaft or align shaft.*
D4: Is loose or damaged end bell overloading shaft? Tighten or replace end bell.*
D5: Are bearings dry? Lubricate.*
D6: Is bearing lubricant dirty, contaminated or of wrong grade? Clean bearings and lubricate with proper grade*
D7: Remove end bells. Are bearings misaligned, worn or damaged? Replace.

*Bearings may have been damaged. If motor still runs noisy or hot, replace bearings.