General Maintenance Guide for Electric Motors: Preventive Processes and Emergency Response

1.Daily monitoring of the “five senses method”

   Sight: Observe housing dust accumulation, grease and ventilation status.

   Hearing: listening to bearing noise (sharp sound = lack of grease, dull sound = wear).

   Tactile: back of the hand temperature measurement, bearing temperature rise > 40 ℃ need to overhaul.

   Smell: insulating paint burnt flavor suggests that the winding is overheated.

   Instrument: Multimeter to measure current balance, megohmmeter to check insulation resistance.

2. Regular maintenance process

   Lubrication management:

       Grease selection: -20℃~120℃ environment with lithium grease (NLGI 2 grade), high temperature scenario with calcium compound sulfonate-based grease.

       Grease injection amount: fill bearing cavity 1/3~1/2, excessive amount leads to heat.

   Electrical system maintenance:

       Tighten terminals to prevent arc burn.

       Clean the carbon brush dust (wire-wound motor), replace it if it is worn out more than 1/2.

   Mechanical parts maintenance:

       Bearing axial clearance > 0.2mm need to be replaced.

       Correct fan blade deformation to avoid uneven heat dissipation.

3. Emergency treatment of faults

   Overheating/smoke: stop the machine immediately → check whether the load is overloaded → check the lack of phase (accounting for 60% of the causes of burning).

   Sudden increase in vibration: stop operation → check the ground bolts → test rotor dynamic balance.

   Abnormal current: three-phase imbalance >10% → detect winding short circuit or power supply voltage