In the process of using DC motors, we sometimes encounter the phenomenon that the equipment cannot be started. In this case, it will not only affect our work progress, but also have a bad impact on the equipment if it is not solved for a long time. To solve this problem, we must first figure out what causes the DC motor to fail to start:
1. Lack of power
Possible situations: For example, the power switch is not closed, the fuse of the front stage is blown, the fuse of the main circuit or control circuit of the motor is blown, the power control devices such as contactors are out of order, and the line wires are broken or loose. The solution is to start from the front fuse, and gradually check the wires and devices of the main circuit and control circuit of the motor, find out the cause and repair it;
2. Motor failure
Possible situations: bad contact between the brush and the commutator due to serious wear, jamming, insufficient spring pressure, etc.; disconnection of the armature winding; disconnection of the excitation winding and no residual magnetism, etc. The treatment method is to disconnect the power supply, and use the resistance gear of the multimeter to check the contact resistance between the brush and the commutator, and the resistance at both ends of each winding. If the resistance value is very large, it means that the fault exists, and then make further inspection to find the breakpoint and repair it;
3. Mechanical failure
The mechanical equipment or transmission mechanism of the
motor is stuck, and the starting load is too heavy. At this time, the power supply should be cut off quickly and the mechanical fault should be found.
The reasons for the failure of the DC motor to start are generally the above three. If we encounter the same problem during use, we can find the reason and solve it according to the above ideas.
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