Answer: Common faults of the isolating switch are: (1) The contact part is overheated. (2) Porcelain insulation damage and flashover discharge. (3) Refusing to pull and close. (4) Error pulling and closing. 2. What is the cause of the overheating of the isolation switch during operation? Answer: The isolating switch is overheated during operation, mainly due to excessive load, increased contact resistance, and incomplete operation. 3. What are the reasons for the increase in contact resistance of the isolating switch? Answer: The reason for the increase of contact resistance is that the repulsive force at the contact between the blade and the nozzle is very large, and the knife edge is not tightly combined, causing surface oxidation and increasing contact resistance. Secondly, the isolation switch will cause arcing during the pulling and closing process, and the contact will be burned to increase the contact resistance. 4. How to judge whether the isolation switch contacts are overheated? Answer: According to the change of the color change paint or the temperature of the test piece in contact with the isolation switch, it can also be determined according to the darkness of the color of the blade. Generally determined according to the infrared temperature measurement results. 5. How to handle the isolation switch contact and contact overheating? Answer: When the contact of the isolating switch and the contact are overheated, first report the dispatch, try to reduce or transfer the load, strengthen the monitoring, and then process according to different wiring: (1) Double busbar wiring. If a busbar side knife is overheated, the overheated isolating switch is taken out of operation by the reverse busbar, and the power failure is overhauled. (2) Single busbar wiring. It is necessary to reduce its load, strengthen monitoring, and take measures to cool down. If conditions permit, stop using it as much as possible. (3) Available bypass breakers with bypass breakers are switched. (4) If the line side isolating switch is overheated, the processing method is basically the same as the single busbar processing method, and the power failure maintenance should be arranged as soon as possible. During maintenance, load should be reduced and monitoring should be enhanced. (5) Open loop operation of one and a half circuit breaker wiring. (6) For the busbar side isolation switch overheating contacts and contacts, after the isolation switch is opened, after on-site inspection to meet the safe distance of the live working, the busbar side down conductor connector can be electrolyzed and then processed. 6. How should the isolation switch electrical operation fail to be checked? Answer: After the electric operation of the isolating switch fails, first check whether there is any error in the operation, and then check whether the operating power circuit, the power supply circuit is intact, and whether the fuse is blown or loose. Is the electrical blocking circuit normal? 7. What should I do if the isolation switch contacts are welded and deformed, the insulator is damaged, and the discharge is severe? A: In case of these situations, power outage should be immediately stopped, and monitoring should be strengthened before power failure. Answer: (1) Due to the mechanical failure of the shaft pin falling off, the wedge plug exiting, the cast iron fracture, or the electrical circuit failure, the cutter bar and the operating mechanism may be disjointed, causing the isolation switch to refuse to close. At this time, the insulating rod is used for operation. , or in the case of personal safety, use the wrench to rotate the shaft of each phase isolation switch. (2) Refuse to trip. When the isolating switch cannot be opened, if the operating mechanism is frozen by ice, you can gently shake it and observe the parts supporting the porcelain bottle and the mechanism to find out the obstacle location according to where the deformation and displacement occur. If the obstacle location occurs in the contact part of the isolating switch, it should not be forced to open. Otherwise, the supporting porcelain bottle may be damaged and cause serious accident. At this time, only the operation mode of the equipment can be changed. 9. How to deal with the isolation switch? Answer: The isolation switch is not in place, most of which is caused by the mechanism corrosion, jamming, maintenance and debugging, etc. When this happens, the isolation switch can be opened and closed. For the 220KV isolation switch, it can be pushed in with an insulating rod and should be applied for power failure if necessary. The high voltage isolating switch should be inspected 1-2 times every 2 years. Building Wire,Sheath Pvc Wire,Pvc Sheath Wire,Grounding Wire Baosheng Science&Technology Innovation Co.,Ltd , https://www.bscables.com
8. What should I do if the disconnector refuses to divide or close?
Electrical Encyclopedia: Summary of common problems with isolating switches!
1. What are the common faults?