What are the common electrical faults and solutions for DC motor motor semi-automatic spring brush machine?
The following are the common electrical faults and solutions for DC motor motor semi-automatic spring brush machine:
1、Brush related faults
Poor contact between brush and commutator:
Failure phenomenon: excessive sparks under the brushes, unstable motor operation, may be accompanied by noise and vibration.
Reason: Brush wear, insufficient or excessive pressure of brush spring, unclean or uneven surface of commutator, brush jammed in brush grip, etc.
Solution: Replace badly worn brushes, correct brush spring pressure to the proper range with a spring scale, clean and grind the commutator surface to ensure that the brushes can slide freely within the brush grip.
Incorrect brush position:
Fault phenomenon: Abnormal motor speed, excessive sparking, and possibly even motor overheating.
Reason: The brush position is not adjusted to the neutral position after installation or overhaul, and the brush holder is loose resulting in the brush position being shifted.
Solution: Adjust the brush holder to the original position or correct the neutral position according to the induction method, tighten the brush holder to ensure the brush position is stable.
2、Winding failure
The armature winding is short-circuited:
Failure phenomenon: abnormal speed when the motor is running, there may be smoke, overheating phenomenon, armature current is too large.
Reason: armature winding insulation damage, short circuit between commutator pieces leads to abnormal current, motor overload operation for a long time.
Solution: Use millivoltmeter to detect whether the armature winding is short-circuited, find out the short-circuit point and repair or replace the armature winding, clean up the debris between the commutator plates to avoid overload operation of the motor.
Excitation winding failure:
Failure phenomenon: the motor can not start, abnormal speed, magnetic field weakening.
Reason: excitation winding disconnection, short circuit, wiring error, long-term operation leads to winding aging.
Solution: Measure the resistance of the excitation winding with a multimeter, check whether it is broken or short-circuited, repair or replace the damaged winding, check whether the wiring is correct and correct the wrong wiring.
3、Power and line failure
Abnormal power supply voltage:
Failure phenomenon: motor speed instability, unable to start, abnormal noise or overheating during operation.
Reason: the power supply voltage is too low, too high, fluctuating, poor contact with the power supply line, broken or short-circuit.
Solution: Use a voltmeter to measure the power supply voltage, adjust the power supply voltage to the rated value, check the connection of the power cord, repair or replace the damaged power cord.
Starter failure:
Failure phenomenon: the motor can not start or start difficult, start the current is abnormal.
Reason: the starter internal components are damaged, wiring errors, starter and motor mismatch.
Solution: Check the internal components of the starter, repair or replace the damaged components, check whether the wiring is correct, and make sure that the starter is matched with the motor.
4、Other faults
Motor leakage:
Failure phenomenon: operator electrocution, motor shell charged, leakage protector tripping, etc..
Reason: motor winding insulation damage, out of the head touching the shell, out of the board or winding insulation damage somewhere, poor grounding device, etc. 1.
Solution: Use 500V megohm meter to measure the insulation resistance of the winding to the ground, such as less than 0.5MΩ should be dried, repair the head of the wire touching the shell, out of the board or somewhere in the winding insulation damage, check the grounding device and ensure that it is good.
Motor overheating:
Fault phenomenon: motor shell temperature is too high, may be accompanied by smoke, odor, etc..
Cause: motor overload, armature winding short circuit or ground, short circuit between commutator pieces, brush spring pressure is too large, motor cooling conditions deteriorate.
Solution: Reduce the load of the motor, check whether the armature winding and the commutator plate are short-circuited and repair, adjust the brush spring pressure, clean the dust filter, air duct, check the fan for defects.
※ If the above ways and means still can not solve the equipment failure, please contact Xinhui Electromechanical Equipment Co., Ltd. technical specialists through the page chat tool to seek help.
