Abstract: A solenoid operated locking mechanism uses a permanent magnet to secure a lockable rod to the solenoid locking mechanism. A solenoid operated plunger determines the location and movement of locking members that extend into a locking chamber, thus controlling the movement of the lockable rod past the locking members. Inserting the lockable rod into the locking mechanism forces the plunger against a spring toward a permanent magnet that holds the plunger in the locked position until an electrical pulse energizes the solenoid which reduces or cancels the permanent magnet's magnetic field and allows the lockable rod to be withdrawn from the locking chamber. The locking mechanism only requires energy to be applied to the solenoid to release the locking rod from the solenoid. The locking mechanism only requires energy to be applied to the solenoid to release the locking rod from the solenoid.

Abstract: An interface assembly is for a trip unit of an electrical switching apparatus including a housing, separable contacts, and an operating mechanism for opening and closing the separable contacts. The trip unit cooperates with the operating mechanism and includes an enclosure, a controller, and a cover member having a plurality of indicia. The interface assembly includes at least one adjustment knob assembly having a post member and a ring member, which includes a cutout. The post member has first and second opposing ends. The ring member is disposed on the second end. The adjustment knob assembly pivots among a plurality of positions to adjust the controller. Each position corresponds to a predetermined setting of the trip unit. The ring member substantially overlays all but one of the indicia, which is exposed by the cutout to indicate the adjustment knob assembly position and corresponding trip unit setting.