Abstract: A removable power supply interlock and extraction mechanism (2) includes a switch guard (16), mounted to the front panel (14) of a module (4), movable between a safe position when the power switch (12) is off to keep it off, and a working position, at which the switch can be freely turned on and off. When the module is being inserted into an electrical unit (16), an actuator (34), mounted to the front panel, is rotated in its insertion rotary direction (50) so the switch guard moves from its safe to its working position; simultaneously a latching element (62) on the actuator engages a latching surface (60) on the unit so to drive the module into the unit until the connectors on the module and unit are fully connected. To remove the module, the power switch is first turned off.