TM 10-6640-239-13 4-50 4-23.    BLACKOUT MICROSWITCH. This task consists of: a. Remove b. Install c. Adjust INITIAL SET-UP Tools Required General Mechanics Tool Kit, (Appendix B, Section III, Item 1) General Safety Instructions WARNING ELECTRICAL SHOCK Before  performing  any  maintenance  actions  on  electrical  equipment,  ensure  all electrical power has been turned off.  Failure to comply with this warning may result in serious injury or death. REMOVE Remove Blackout Microswitch.  See Figure 4-13. a. Position circuit breaker(s) to OFF. (1)   Microswitch for rear or curbside door, position Main Power Panel circuit breakers A1CB9, A1CB11, and A1CB13 to OFF. (2)   Microswitch for mechanical room door, position Power Panel No. 2 circuit breaker A15CB10 to OFF. b. Verify all lighting is off to ensure power has been removed from microswitch. c. Remove eight screws (1), washers (2), NSN plate (3) and cover plate (4) for rear or curbside blackout microswitch or six screws (1), washers (2), NSN plate (3) and cover plate (4) for mechanical room blackout microswitch. d. Remove eight screws (5), lockwashers (6) and pull both microswitches (7) forward from door switch box (8). f. Tag and disconnect wires from back of microswitches (7). g. Remove three screws (9), lockwashers (10), washers (11), spacers (12), and door switch box (8) for rear or curbside blackout microswitch or two  screws (9), lockwashers (10), washers (11), spacers (12), and door switch box (8) for mechanical room blackout microswitch. INSTALL Install Blackout Microswitch.  See Figure 4-13. a. Install door switch box (8) and secure with three screws (9), lockwashers (10), washers (11), and spacers (12) for rear or curbside blackout microswitch or two screws (9), lockwashers (10), washers (11), and spacers (12) for mechanical room blackout microswitch. b. Connect wires as tagged to back of microswitches (7). Remove tags. c. Install microswitches (7) in door switch box (8) and secure with eight screws (5), and lockwashers (6). d. Install cover late (4) and secure with eight screws (1), washers (2), and NSN plate (3) for rear or curbside blackout microswitch or six screws (1), washers (2), and NSN plate (3) for mechanical room blackout microswitch. e. Position appropriate circuit breaker(s) to ON and verify proper operation.