The motor is represented by the letter M (old mark D) in the circuit, and its main function is to generate driving torque. As the power source of electrical appliances or various machines, the generator is represented by the letter G in the circuit, and its main function is to convert mechanical energy into electrical energy.
According to the type of working power supply, motors can be divided into DC motors and AC motors. The working principle of DC generator is to use the commutation function of brush to change the AC electromotive force induced in armature coil into DC electromotive force when it is led out from the end of brush through commutator.
Inspection method before starting the motor:
1, the insulation resistance between windings and between windings and ground should be checked before use for new or long-term disabled motors. 500V insulation resistance meter is usually used for motors below 500V; 500- 1000V insulation resistance meter for motor; For motors above 1000V V, use a 2500V insulation resistance meter, and the working voltage of insulation resistance per kilovolt shall not be lower than1mΩ, and it shall be measured when the motor is cooled.
2. Check the appearance of the motor for cracks, whether all fastening screws and parts are complete, and whether the motor is fixed in good condition.
3. Check whether the motor transmission mechanism works reliably.
4. Display the data displayed on the nameplate, such as voltage, power, frequency, connection, speed, etc. , consistent with the comparison of power supply and load.
5. Check whether the ventilation and bearing lubrication of the motor are normal.
6, pull the motor shaft, check whether the rotor can rotate freely, rotating with or without noise.
7, check the motor brush assembly and brush lifting mechanism is flexible, brush lifting handle position is correct.
8, check whether the motor grounding device is reliable.