TM 10-6640-239-13 4-39 4-19.    EXPLOSION PROOF DISTRIBUTION BOX A3 COMPONENTS. This task consists of: a. Remove b. Install INITIAL SET-UP Tools Required General Mechanics Tool Kit, (Appendix B, Section III, Item 1) Materials/Parts Required Lockwashers, (52) Self locking Nuts (2) 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 1. Disassemble Explosion Proof Distribution Box A3.  See Figure 4-9. a. Open main circuit breaker A1CB1 and turn generator off. NOTE Mark distribution box cover left side before removing. b. Remove 18 screws (1), lockwashers (2), washers (3), and access panel (4) to gain access to distribution box A3 (5) which is located below Main Power Panel.  Discard lockwashers. c. Remove 28 mounting screws (6), lockwashers (7), and washers (8) and cover (9).  Discard lockwashers. 2. Remove Timer Relay A3K1 or A3K6. a. Pull relay (10) from socket (11). 3. Remove Relay A3K2 or A3K5. a. Remove four screws (12), lockwashers (13), and washers (14) and pull relay mounting plate (15) forward to gain access to relay mounting hardware.  Discard lockwashers. b. Remove two screws (16), lockwashers (17), washers (18) and relay A3K2 or A3K5 (19).  Discard lockwashers. c. Tag and disconnect wiring from relay A3K2 or A3K5 (19) by removing terminal screw (20). 4. Remove Terminal Board TB1. a. Tag and disconnect wiring from terminal board TB1 (21). b. Remove two screws (22), washers (23), self locking nuts (24), terminal board TB1 (21), and terminal board marker strip (25).  Discard self locking nuts.