TM 10-6640-215-13 4-16. REMOVE/INSTALL LIGHT BALLAST-continued. e. Tighten diffuser captive screws. f. Restore power to lights by placing circuit breakers AICB9, A1CB11 and AICB13 in Main Power Panel in the ON position. 4-17. REMOVE/INSTALL EMERGENCY LIGHT BALLAST. This task covers:   a. Removal b. Installation INITIAL SETUP: Tools Required General Mechanics Tool Kit, (Appendix B, Section III, Item 2) Equipment Condition Power to lights turned OFF by placing A1CB9, AICB11, and AICB13 in the OFF position at Main Power Panel. General Safety Instructions WARNING ELECTRICAL SHOCK Before performing any maintenance actions on electrical equipment, ensure all electrical power has been turned off.  Death or serious injury may occur from failure to do this. REMOVAL Remove Ballast.  See figure 4-6. a. Unlatch and open ballast box door. b. Disconnecting ballast plug from connector. c. Remove indicator light by removing tee handle and clamp on right wall bracket.  Retain clamp for reuse. d. Remove tee handle and clamp at top of ballast and remove ballast by lifting up from bottom support bracket. Retain clamp for reuse. INSTALLATION Install Ballast.  See figure 4-6. a. Position new ballast onto bottom support bracket. b. Secure top of ballast with tee handle and clamp. c. Secure indicator light on right wall bracket with tee handle and clamp. 4-35