TROOP WARNING SYSTEM WITHOUT 17
The troop warning system provides visual and audible
signals for the troops. The system has two troop warning
boxes, one in the forward section of the cabin at sta. 120
and the other in the ramp area at sta. 575. The system
also includes two indicator lights, two switches, and a
relay in the overhead panel. The system operates from
the 28 volt No. 2 dc bus.
When TROOP ALARM BELL circuit breaker is
closed, 28 vdc from No. 2 dc bus is applied to
TROOP ALARM switch. When this switch is
ON, 28 vdc sounds both alarm bells. The bells
continue to sound until the switch is set to OFF.
When TROOP ALARM JUMP LT circuit breaker
is closed, 28 vdc from No. 2 dc bus is applied
to TROOP JUMP LTS switch and to TROOP
JUMP LTS indicator-switches. The 28 vdc to
the indicator-switches is used to test the lamps.
When the lens on the indicator-switches are
pressed, 28 vdc lights the integral lamp.
There are two dimming relays in this system.
Jump lights dimming relay controls the brightness
of the jump lights in both troop warning
boxes. Signal lights dimming relay controls the
brightness of the TROOP JUMP LTS in the
overhead panel. When either relay is released,
its associated lights come on at full brightness.
When either relay is operated, its associated
lights come on at reduced brightness. These
relays are coordinated with other systems to
ensure that the jump lights are not bright when
nearby lights are dim. When the red cabin and
ramp dome lights are on, 28 vdc from the cabin
and ramp lighting system operates jump lights
dimming relay. When the caution lights are set
to DIM, 28 vdc from the master caution panel
circuit operates signal lights dimming relay.
When TROOP JUMP LTS switch is set to RED,
three red jump lights come on. When TROOP
JUMP LTS switch is set to GREEN, three green
jump lights come on.