TM 10-6640-239-13 4-92 3. Remove Gas Alarm Detector Element.  See Figure 4-30. a. Remove power from all equipment. b. Position all Main Power Panel circuit breakers to OFF. c. Shut down generator. d. Loosen set screw (1) on shield assembly (2).  Unscrew and remove shield assembly. e. Unplug element (3). INSTALL 1. Install Gas Alarm.  See Figure 4-30. a. Carefully place gas alarm (3) into position on wall and secure with four screws (5), lockwasher (6), washers (7) and spacers (8). b. Loosen latch (1) and swing open door (2) of gas alarm unit (3). c. Loosen captive release screw and swing panel out. d. Carefully remove circuit board. e. Connect flexible conduits (4) from buzzer and power input fitting and tighten conduit nuts. f. Connect wires as tagged and secure with terminal screws.  Remove tags. g. Carefully install circuit board. h. Close panel and tighten captive screw. i. Close door (2) and secure with latch (1). 2. Install Gas Alarm Buzzer.  See Figure 4-30. a. Connect wires as tagged to buzzer (13).  Remove tags. b. Place buzzer (13) in junction box (11) and secure with mounting collar (12). c. Place cover plate (10) on junction box (11) and secure with four screws (9). d. For calibration procedure, refer to TM 10-6665-297-13&P. 3. Install Gas Alarm Detector Element.  See Figure 4-31. a. Plug detector element (3) into detector body. b. Carefully screw shield assembly (2) over detector element (3) ending with setscrew (1) up. c. Tighten setscrew (1) on shield assembly (2). d. For calibration procedure, refer to TM 10-6665-297-13&P. TEST Test Gas Alarm System. a. Power up generator set and apply power to laboratory.  After purge cycle is completed turn on electrical power. b. Depress the alarm test pushbutton located on the control module front panel. c. Depress reset button to silence alarm. CALIBRATE Refer to technical manual listed in Appendix A for calibration procedures.