The shunt tripping device is a kind of tripping device which is excited by voltage source, and its voltage is independent of the main circuit voltage. The shunt tripping device is an accessory for remote control of the separation gate. The circuit breaker can be reliably divided when the supply voltage is equal to any voltage between 70%-110% of the rated control supply voltage. Shunt tripping device is a short-term work system, coil power-on time generally can not exceed 1S, otherwise the line will be burnt. Molded case circuit breaker to prevent the coil from burning, in the shunt tripping Coil Series A micro-switch, when the shunt tripping device through the armature suction, micro-switch from the normally closed state to the normally open, because the shunt off the power of the control line is cut off, even if the artificial hold the button, the shunt coil will never power this will avoid the formation of the coil burning loss. When the circuit breaker is closed again, the Microswitch is re-located in the NC position.