Preventive maintenance of motors checklist

Watch for discoloration, scoring marks, or metal particles in the lubricant. Listen for grinding, squealing, or rumbling noises during operation. Feel for excessive heat or vibration. These indicators suggest bearing deterioration requiring immediate attention. The checklist helps you systematically document these observations, creating a timeline of bearing condition for predictive maintenance.

Look for discolored insulation, burnt smell, or brittle/cracked wire coverings. The resistance measurements you record should remain consistent between phases and over time. Increasing resistance may indicate deteriorating connections, while decreasing resistance often suggests insulation breakdown. Use the checklist’s measurement section to track these subtle changes before catastrophic failure occurs.

Always disconnect and lock out power before inspecting motors. Verify zero voltage with a meter before touching any components. Allow motors to cool before handling. Use appropriate PPE including electrical safety gloves for resistance testing. Never perform maintenance alone on larger motors. The checklist includes verification steps to ensure these critical safety procedures are followed.