Relationship between opening and closing the switch and the energy storage motor

What is a stored energy mechanism (SEM)?

A Stored Energy Mechanism (SEM) is a mechanism that opens and closes a device (Switch) by compressing and releasing spring energy. The operating handle compresses a set of closing springs and a separate set of opening springs. These springs store the mechanical energy of this movement and are held in the compressed state by close and open latches.

How does an operating handle work?

The operating handle compresses a set of closing springs and a separate set of opening springs. These springs store the mechanical energy of this movement and are held in the compressed state by close and open latches. (In other words, the springs are pre-charged).

How does a SEM motor work?

The close or trip latches can be moved by local mechanical push buttons or by the plunger of close or trip electrical coils. The speed of operation is independent of the speed of the operator. The operating time of the SEM mechanisms is approximately 100 milliseconds. The motor operator will recharge the springs in approximately 3 seconds.