An enclosed electrical switching apparatus assembly comprising an enclosure assembly and an electrical switching apparatus, said enclosure assembly comprising a housing assembly and a movable cassette, said enclosure assembly housing assembly comprising a number of sidewalls and a movable door, said enclosure assembly housing assembly sidewalls and movable door defining an enclosed space, said door movably coupled to said enclosure assembly housing assembly sidewalls and movable over a path between a closed, first position and an open, second position, said cassette movably disposed in said enclosure assembly enclosed space and structured to move between an inserted, first position and a withdrawn, second position, said electrical switching apparatus disposed on said cassette, said electrical switching apparatus comprising an operating mechanism handle, said operating mechanism handle movable over a path between a closed, first position, wherein said electrical switching apparatus is energized, and an open, second position, wherein said electrical switching apparatus is de-energized, the enclosed electrical switching apparatus assembly further comprising a mechanical switch-door interlock assembly, the mechanical switch-door interlock assembly comprising: a mounting assembly including a number of sliding coupling components; an actuator assembly including a body, a door sensor, an operating mechanism handle actuator, and a number of sliding coupling components; said door sensor coupled to said actuator assembly body; said operating mechanism handle actuator coupled to said actuator assembly body; said actuator assembly body slidably coupled to said mounting assembly; said mounting assembly structured to be coupled to said cassette at a location wherein said operating mechanism handle actuator is disposed in said operating mechanism handle path and said door sensor is disposed in said door path; wherein said actuator assembly body moves between an operating, first position, wherein said operating mechanism handle actuator does not operatively engage said operating mechanism handle, and a non-operating, second position, wherein said operating mechanism handle actuator operatively engages said operating mechanism handle and moves said operating mechanism handle to said second position; wherein, when said door is in said first position, said door operatively engages said door sensor and moves said actuator assembly body to said actuator assembly body first position; and wherein, when said door is in said second position, said door does not operatively engage said door sensor allowing said actuator assembly body to move into said second position, wherein said actuator assembly body translates between said first position and said second position. a mounting assembly including a number of sliding coupling components; an actuator assembly including a body, a door sensor, an operating mechanism handle actuator, and a number of sliding coupling components; said door sensor coupled to said actuator assembly body; said operating mechanism handle actuator coupled to said actuator assembly body; said actuator assembly body slidably coupled to said mounting assembly; said mounting assembly structured to be coupled to said cassette at a location wherein said operating mechanism handle actuator is disposed in said operating mechanism handle path and said door sensor is disposed in said door path; wherein said actuator assembly body moves between an operating, first position, wherein said operating mechanism handle actuator does not operatively engage said operating mechanism handle, and a non-operating, second position, wherein said operating mechanism handle actuator operatively engages said operating mechanism handle and moves said operating mechanism handle to said second position; wherein, when said door is in said first position, said door operatively engages said door sensor and moves said actuator assembly body to said actuator assembly body first position; and wherein, when said door is in said second position, said door does not operatively engage said door sensor allowing said actuator assembly body to move into said second position, wherein said actuator assembly body translates between said first position and said second position.