What are the measures to improve the tripping of High-voltage switchgear?

2025-10-16 16:19:47

After disconnecting the output terminal of the cable from the High-voltage switchgear, the absolute resistance of the cable measured with a multimeter is infinite, and the phase to phase resistance meets the standard value. The motor stops manual turning, and the rotor rotates forward and backward without blockage. Stop manually closing the automatic air switch and AC contactor, test the three-phase continuity, and ensure normal continuity without resistance.

After the LM equipment was put into reverse phase maintenance, it was tested again and showed a reverse phase sequence fault, triggering an alarm and tripping. When switching the positions of A-B phase cables through LM equipment, the reverse phase sequence fault was still displayed during the second trial run. Simultaneously stop the position exchange of A-B phase cables and corresponding voltage lines, and try running again.

Reflecting on the suction coil of the AC contactor with a multimeter, the displayed value is normal, and connecting the coil to the 220V voltage suction line is normal. Reflect on the medium-voltage switchgear and on-site red and green indicator lights with a multimeter, and measure normally. Disconnect the secondary cable of the Complete set of electrical switchgear secondary terminal, disconnect the secondary cable on the operating column terminal, and measure the resistance between the secondary terminals behind the cabinet without short circuiting, which is infinite.

Measure the resistance between each cable of the secondary wire and display it as infinite. Measure the resistance between the terminals that are not connected between the operation columns, indicating infinite. After disconnecting the secondary fuse, measure the contact resistance between each node of the secondary circuit and the cabinet starting from the secondary fuse, and display infinite.

Stop insulation testing on the cable and motor, and the measurement results are normal. The High-voltage switchgear is running again, and the parts are running normally. The LM is running normally and the display is normal. After the High-voltage switchgear, the terminal disconnects the cable once, and the High-voltage switchgear runs on power.

Manually test the LM equipment's restart function, the automatic air switch will be turned off again within 2 seconds, and then start maintenance will be normal. If the system is restarted, the LM display screen will show that it has successfully started again. Transfer the LM power supply to the lower end of switch A, and then manually turn off the automatic air switch within 2 seconds. The Switchgear partial discharge will no longer start, and there will be no problem recorded with LM.