What faults may occur during the operation of Rolling Mill Motor?

1. Electrical fault
Short circuit fault:
Phase-to-phase short circuit: Due to the insulation damage of the motor winding, a short circuit occurs between the windings of different phases. This may be caused by insulation aging, overvoltage shock, mechanical damage, etc. due to long-term operation. Phase-to-phase short circuit will generate a large short-circuit current, causing the motor to heat up rapidly or even burn out.
Turn-to-turn short circuit: A short circuit occurs between different turns in the same phase of the motor winding. Turn-to-turn short circuits are usually caused by poor winding manufacturing, insulation material defects, overcurrent shock, etc. Turn-to-turn short circuits will increase the current of the motor and unbalance the magnetic field, causing motor vibration, increased noise, and temperature rise. In severe cases, the winding will burn out.
Grounding fault:
Winding grounding: An electrical connection occurs between the motor winding and the casing or other grounded components, resulting in a grounding fault. A grounding fault may be caused by insulation damage, moisture, corrosion, etc. of the winding. A grounding fault will cause the motor casing to be charged, posing a threat to personal safety, and will also cause the motor protection device to operate, causing the motor to stop running.
Cable grounding: The cable connecting the motor has a grounding fault, which may be caused by cable insulation damage, external force damage, etc. Cable grounding will cause the motor to fail to operate normally or even damage the motor.
Overload fault:
Motor load is too large: During the rolling process, if the load exceeds the rated load of the motor, the motor will be overloaded. Overload will increase the current of the motor and increase the temperature. Long-term overload will damage the insulation of the motor and shorten the service life of the motor.
Frequent motor starting: Frequent motor starting will also cause overload faults. Every time the motor is started, a large starting current is required. If the number of starts is too many, the temperature of the motor will increase, the insulation aging will accelerate, and it is easy to cause faults.
Phase loss fault:
Power supply phase loss: One phase of the power supply is disconnected or has poor contact, causing the motor to run in phase loss. Phase loss operation will cause the magnetic field of the motor to be unbalanced, generate greater vibration and noise, increase current, increase temperature, and easily burn the motor.
Motor winding break: A broken wire inside the motor winding will also cause a phase loss fault. Winding breakage may be caused by manufacturing defects, overcurrent shock, mechanical damage, etc.
2. Mechanical failure
Bearing failure:
Wear: Long-term operation will cause wear between the rolling element and the raceway of the bearing, resulting in increased bearing clearance, increased motor vibration and noise. When the wear is severe, the bearing will be stuck and the motor will not be able to operate normally.
Overheating: Poor bearing lubrication, overload operation, improper installation and other reasons may cause bearing overheating. Overheating will shorten the life of the bearing and even damage the bearing.
Damage: Bearings may be damaged due to external impact, improper assembly, quality problems and other reasons. Bearing damage will change the gap between the rotor and stator of the motor, generate friction, cause motor vibration, increase noise, temperature rise, and in severe cases burn the motor.
Shaft failure:
Bending: If the motor is impacted by external force or uneven force during installation, transportation or operation, the shaft may be bent. Shaft bending will cause uneven air gap between the rotor and stator of the motor, generate vibration and noise, and affect the performance and life of the motor.
Breakage: If the shaft is subjected to excessive torque or fatigue stress during long-term operation, it may break. Shaft breakage will cause the motor to stop running immediately, seriously affecting production.
Fan failure:
Blade damage: If the fan blade is hit by foreign objects or worn for a long time during operation, the blade may be damaged. Blade damage will affect the heat dissipation effect of the motor, increase the temperature of the motor, and affect the performance and life of the motor.
Loose fan: The connection between the fan and the motor shaft is loose, which will cause the fan to run unstably, generate vibration and noise. In severe cases, the fan may fall off, causing damage to the motor and surrounding equipment.
3. Other faults
Overheating fault:
Poor motor heat dissipation: Failure of the motor's heat dissipation system, such as fan damage, ventilation duct blockage, etc., will cause poor motor heat dissipation and temperature increase. Overheating will accelerate the aging of the motor's insulation and reduce the performance and life of the motor.
Excessive ambient temperature: If the operating environment temperature of the motor is too high, the motor temperature will also rise. In a high temperature environment, the heat dissipation effect of the motor will be affected, and overheating faults are prone to occur.
Vibration fault:
Motor imbalance: Motor rotor imbalance, improper installation, bearing wear and other reasons may cause motor vibration. Vibration can loosen and damage the motor's parts, affecting the performance and life of the motor.
Unbalanced rolling load: During the rolling process, if the load is unbalanced, the motor will be subjected to uneven force and vibrate. The vibration will be transmitted to the foundation of the motor and the surrounding equipment, affecting the stability of the entire production system.
Noise failure:
Internal motor failure: Motor bearing failure, winding failure, fan failure, etc. may cause abnormal noise in the motor. Noise affects the working environment and may also be a precursor to motor failure, which requires timely inspection and treatment.
Transmission system failure: Failure in the transmission system between the motor and the rolling equipment, such as gear wear, loose coupling, etc., may also cause increased noise. Noise affects the normal operation of the equipment and may also affect the health of the operator.
If you want to know about the possible failures of the Rolling Mill Motor during operation, you can contact MCM Electric Machinery, and we will do our best to help you!