Electric motor maintenance skills?

Electric motor maintenance skills?

The maintenance techniques for electric motors include the following aspects:

Visual inspection method:

Observe whether there are any abnormal phenomena during the operation of the motor, such as smoking, slowing down the speed, sparking when stopping, severe vibration, discoloration of contact points and connections, burn marks and smoke stains, etc.

Listen: Monitor the sound of the motor running, the normal sound should be a uniform and light "buzzing" sound, without any noise. Abnormal sounds may include electromagnetic noise, bearing noise, ventilation noise, mechanical friction noise, etc., which may be precursors or phenomena of faults.

Touch: Touch the motor with your hand to check if the screws are loose and if the casing is overheated.

Smell: When powered on, smell the electric motor with your nose for any burnt smell, which may be a sign of burnt terminals or windings.

Inspection and testing:

Appearance inspection: Remove the dirt and oil sludge from the shell, check for cracks, deformation, loose and corroded junction boxes, abnormal fan operation, etc.

Insulation inspection: Use an insulation resistance meter or voltage tester to check the insulation of the winding to ground and between phases.

Winding inspection: Use a multimeter or oscilloscope to check for short circuits, open circuits, grounding, and other phenomena in the winding, and observe for burning or open circuits.

Bearing inspection: Use a vernier caliper or micrometer to check the wear, clearance, and lubrication of the bearing, and determine whether it needs to be replaced.

Rotor inspection: Check the rotor for defects and bore marks, the squirrel cage rotor for broken bars or rings, and the collector ring and electric brush of the wound rotor for excessive wear and burn marks.

Troubleshooting:

Problems with stator and rotor, such as uneven air gap, unbalanced three-phase current, and loose iron core, can be solved by trimming insulation, replacing bearings, and inspecting the stator and rotor iron cores.

Bearing problems: Bearing wear, lack of oil, excessive or insufficient clearance can be solved by replacing bearings, cleaning bearings, adding oil, and other methods.

Winding problems: winding short circuit, open circuit, grounding, etc., can be solved by repackaging insulation, replacing windings, and other methods.

Power supply issues: power failure, blown fuse, overcurrent relay set too small, control equipment wiring errors, etc. can be resolved by checking the power circuit, replacing fuses, adjusting relay settings, correcting wiring, and other methods.

Maintenance and upkeep:

Regular cleaning: Regularly clean the motor casing to maintain good grounding or zero connection.

Lubrication and maintenance: Regularly inspect and replace bearing grease to ensure good lubrication.

Check fasteners: Regularly inspect and tighten the motor foot screws, end cap screws, etc.

Ventilation and heat dissipation: Ensure good ventilation of the motor to avoid overheating.

By using the above techniques and methods, it is possible to effectively diagnose and repair motor faults, ensuring their normal operation. It is recommended to follow safety operating procedures during the maintenance process, wear necessary protective equipment, and seek professional assistance when necessary.