TM 10-6640-238-13 5-53 5-24.    PYROMETER FUSE BOX. 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, (4) 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 Pyrometer Fuse Box.  See Figure 5-20. a. On Main Power Panel set circuit breaker A1CB19 to OFF. b. Remove two screws (1), latches (2), and open cover (3). c. Tag and disconnect wiring from relay (4). d. Remove two screws (5), washers (6), and relay (4). e. Tag and disconnect wiring from terminal board (7). f. Remove two screws (8) and terminal board (7). g. Remove four screws (9) and panel (10). h. Remove conduit (11) and wiring from pyrometer fuse box (12). i. Remove four screws (13), lockwashers (14), washers (15), and pyrometer fuse box (12).  Discard lockwashers. INSTALL Install Pyrometer Fuse Box.  See Figure 5-20. a. Install pyrometer fuse box (12) and secure with four screws (13), lockwashers (14), and washers (15). b. Install conduit (11) and wiring to pyrometer fuse box (12). c. Install panel (10) and secure with four screws (9). d. Install terminal board (7) and secure with two screws (8). e. Connect wiring as tagged to terminal board (7). f. Install relay (4) and secure with two screws (5) and washers (6). g. Connect wiring as tagged to relay (4). h. Close cover (3) and secure with two latches (2) and screws (1). i. On Main Power Panel set circuit breaker A1CB19 to ON.