When grease contaminates a motor winding, what is a likely consequence?

When grease contaminates a motor winding, what is a likely consequence?

• A. The winding insulation may deteriorate
• B. The bearings will wear quickly
• C. The motor will produce more power
• D. The windings become magnetic

Answer: (A)

Grease on motor windings harms the insulation that keeps electrical current from leaking between turns. The winding enamel or insulation is designed to withstand heat, moisture, and electrical stress. When grease contaminates the windings, it can soften or weaken that insulation and can carry moisture and other contaminants into the insulation layer. This lowers the dielectric strength and creates pathways for leakage, arcing, or partial discharge, which accelerates insulation deterioration and can lead to winding failure. The grease also hampers heat dissipation, allowing the winding to overheat and age more quickly.

Other outcomes listed don’t fit this scenario: bearing wear is tied to lubrication issues elsewhere, not the winding insulation, motor output won’t increase due to grease contamination, and windings aren’t made magnetic by grease.