Maintenance Method for Grounding Fault of DC Motor Armature Winding

When repairing the grounding fault of the armature winding of a DC motor, we can use various techniques. Firstly, it is necessary to ensure the use of convenient and practical maintenance tools, such as armature maintenance lights. Connect the lamp to the circuit and clarify the fault situation through the operation method. If the light is on after closing the switch, it is likely that there is a grounding fault. At this point, you can adjust the position of the commutator and observe the brightness changes of the light to find the grounding point more clearly. Additionally, if recent discharge sparks are detected, it may also indicate the presence of a ground fault.

The handling of grounding points needs to be determined based on specific circumstances. If grounding occurs at the lead out line, it may be necessary to strengthen the insulation measures of the iron core, such as increasing the number of insulation layers. If the grounding point is located on the outer layer of the slot, you can try applying insulating paint to solve the problem. Through these techniques and methods, we can more effectively troubleshoot grounding faults in the armature winding of DC motors, ensuring their normal operation.

The verification lamp method is widely favored for its simplicity in the maintenance of armature winding grounding faults. The required tools include a 12V power supply, a calibration light, and a switch. When operating, first close the switch and observe if the light bulb is on. If the light bulb is on, it indicates that there is a ground fault in the armature winding. At this point, by adjusting the position of the commutator, if the brightness of the bulb gradually increases, it means that the commutator is gradually approaching the grounding point; On the contrary, it indicates that the distance is gradually increasing. When the commutator is closest to the grounding point, spark discharge between the winding and the iron core often occurs. If the light bulb does not light up, it indicates that there is no grounding fault in the winding.

The repair methods vary depending on the location of the grounding point. If the grounding point is located at the end of the commutator and winding lead, two layers of insulation paper can be added between the grounding point and the iron core to strengthen the insulation. If the grounding point is outside the iron core slot, only insulation paint needs to be applied. However, if there are many grounding points or they are located inside the winding, it may be necessary to rewire the armature winding or even replace the entire armature.