Measures of Air Circuit Breaker after Breaking Short Circuit Current
Every time the short circuit current is disconnected, the Air Circuit Breaker should be inspected. The contents of the inspection and the methods of fault treatment are as follows.
1. Contact system
(1) Smoke marks on main and arc contacts are wiped with alcohol;
(2) If small metal particles form on the contact surface, they should be cleaned and smoothed.
(3) If the thickness of silver alloy contact layer on the main contact (dynamic and static contact) is less than 1 mm due to electrical wear, it must be replaced, and the dynamic and static contact should be replaced at the same time.
(4) Check the contact pressure spring, if it fails due to overheating, it should be replaced in time;
(5) Check whether there is a break in the soft connection. A few of the faults need to remove the broken zones. If most of the zones are broken, the soft connection should be replaced.
2. Arc extinguishing system
(1) Clean up the metal particles and soot on the wall of the arc extinguishing chamber and the grids, and replace them if the grids are seriously welded or burned.
(2) If the arc extinguishing chamber is damaged, it is not allowed to be used again and must be replaced.
(3) The newly exchanged arc extinguishing chamber should be dried before use to ensure good insulation.
3. Operating mechanism and free release mechanism
(1) Lubricating oil can be properly added first;
(2) Operate switch-on several times with electric operating mechanism and manual handle respectively. The operating mechanism should be flexible and the Air Circuit Breaker should be closed reliably. When the switch-off button is pressed, the Air Circuit Breaker should be disconnected instantaneously.