1. the circuit breaker is in the closed position;

2. the handle is not fully inserted into the advance hole of the chassis carriage

3. the propulsion mechanism is not fully in the experimental position, resulting in the chassis carriage tongue not being unlocked from the cabinet

1. the circuit breaker is in the unstored state

2. the circuit breaker is in the closed state

3. the closing blocking coil is selected and the auxiliary power supply is not connected

4. the secondary circuit is inaccurate, or the secondary components such as auxiliary switch and closing decoupler are damaged

5. the trolley type circuit breaker is not fully in the working position or test position

6. deformation of the circuit breaker frame after installation in conjunction with the cabinet

1. the circuit breaker is already in the breaking state

2. the secondary circuit is inaccurate, or the secondary components such as auxiliary switches and circuit breaker decouplers are damaged

3. after installation with the cabinet, the frame of the circuit breaker is deformed resulting in closing over dead point