1. During the regular maintenance and inspection of outdoor vacuum circuit breaker, the general tasks are: measuring the overtravel and stroke of the circuit breaker; Check the vacuum interrupter for air leakage; Check whether the grounding wire of the secondary circuit is loose; Check whether the contact of auxiliary switch is good; Measure the resistance value of each phase main circuit; Remove the dust adsorbed on the conductive part and insulator; Check the fastening bolts for looseness.
2. Precautions: the switch tube of VCB breaker in operation should be monitored at any time. If it is found that the contact in the switch tube is not connected or only one contact is charged, and the red or milky glow appears on the inner wall of the switch tube, the emptiness in the tube is reduced and can not be used any more. The vacuum switch tube should be replaced immediately.
Protect large silicon rectifier and other high voltage electrical equipment.
When the vacuum circuit breaker is in the closing position, its ground insulation is borne by the supporting insulator. Once the permanent ground fault occurs in the circuit connected to the vacuum circuit breaker and the ground fault point is not cleared after the circuit breaker tripping, the ground insulation of the current bus is also borne by the vacuum gap of the circuit breaker fracture; When various faults break, the vacuum insulation gap between a pair of contacts on the fracture surface should withstand the effects of various recovery voltages without breakdown.