1. What are the common faults?

Answer: switch common faults are: (1) contact overheating. (2) the porcelain insulation flashover damage and discharge. (3) refuse to pull opening and closing. (4) error and closing.

2. during the operation of disconnector contacts overheating what is the cause?

Answer: switch overheating during operation, mainly overload, the contact resistance increases, operating without the perfectly good cause.

3. isolate the switch contact resistance increases due to what?

A: contact resistance increases due to: blade and knife mouth contact repulsion is larger, knife edge is not strict, causing the surface oxidation, the contact resistance increases. Second process of isolating switch, can cause arcing and burn contact, the contact resistance increases.

4. how to tell if contacts of disconnector overheating?

Answer: according to the disconnector contacts color paint or try judging changes of temperature and color, can be determined according to the degree of color dark blade. Generally determined by infrared temperature measurement results.