Abstract: An assembly supporting a plug-on switch unit on a mounting pan pivotally supported within a unit enclosure of an electrical control center and movable between a first position in which the plug-on jaws of the switch unit are connected to respective bus bars within the motor control center and a second position in which the plug-on jaws are spaced away from the bus bars. The assembly includes a handle operator movable between a first position indicating that the switch unit is in an "OFF" condition and a second position indicating that the switch unit is in an "ON" condition. Interlock features are provided to prevent movement of the mounting pan from its first position to its second position unless the handle operator is in its first position and also to prevent removal of the unit enclosure from the motor control center unless the mounting pan is in its second position.