What is the cause of the burning of electric motor tools?
(1) the installation and maintenance of motor, mistakenly triangle motor winding connection with Y connection, or mistakenly Y connection with the triangle. (2) winding phase, inter turn short circuit or earthing lead to winding current increase and unbalanced three-phase current, which makes motor overheating. (3) pole group coil connecting each phase coil number of incorrect or uneven distribution, resulting in the no-load current of three-phase unbalance, and the current is too large; when the motor is running the three-phase current imbalance, noise and vibration, motor overheating. (4) the stator and rotor become friction heated. (5) the cage rotor of induction motor is broken or the winding rotor winding is broken. The motor output is insufficient and overheated. (6) motor bearing overheating.
The direct cause of motor burnout is high temperature.The common fault of motor is divided into mechanical fault and electrical failure in two categories, including: electrical fault of stator and rotor winding short circuit, open circuit, and start the equipment failure; mechanical failure including: excessive vibration, overheating of bearing, the stator and rotor friction and abnormal noise.
(1) the motor is running over load for a long time, the stator current is much higher than the rated current, and the motor is overheated. (2) when the motor starts frequently, the starting time is too long or the interval between start time is too short, the temperature rise of the motor will be too high. (3) the mechanical failure of the traction motor causes the output of the motor to increase, or not to be locked or the rotating speed drops sharply, so that the motor current rises sharply and is overheated. (4) the working system of the motor does not match the load system; for example, the motor with short period operation is used to drive the load for continuous long term operation.3, environmental and ventilation cooling reasons (1) the motor working environment and ventilation is too high, the motor can not get good ventilation, heat dissipation and overheating. (2) dust, motor oil too much, is not conducive to the heat dissipation of the motor. (3) the wind shield or the wind shield is not installed in the wind hood, which leads to poor wind path and bad heat dissipation of the motor. (4) fan damaged, deformed, loose, or not installed or installed, so that the motor ventilation, poor heat. (5) the enclosure of the enclosed motor shell has too many defects and the radiating area is reduced; or the blocking of the protective motor fan will cause the ventilation of the motor to be badly cooled and the temperature rise too high.
