TM 55-1520-240-23-7
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LIGHTING SYSTEMS
(Continued)
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CABIN AND RAMP LIGHTING SYSTEM WITHOUT 17
Description
The cabin and ramp lighting system provides white
and red lighting for the cabin and ramp areas. The
system includes five dome lights, two toggle switches, a
pushbutton switch, and two relays. The system operates
from the 28 vdc switched battery bus.
Operation
1.
When CABIN & RAMP LIGHTING circuit breaker
is closed, 28 vdc from the switched battery bus is
applied to terminals B2 of red relay K1 and white
relay K2. Both relays cannot be operated at the
same time. When red relay K1 is operated, the
28 vdc is applied through relay K1. This voltage
lights the red lamp in each of the five dome lights.
When white relay K2 is operated, the 28 vdc is
applied through relay K2. This voltage lights the
white lamp in each of the five dome lights.
2.
When both relays are released, the red and
white lamps are out. When momentary WHT ON
switch is pressed, 28 vdc from the circuit breaker
is applied to white relay K2. The relay energizing
circuit is completed to ground through CABIN &
RAMP LIGHTS switch. Contacts A1-A2 provide
a holding circuit for relay K2. The holding circuit
provides 28 vdc for relay K2 through CAB &
RAMP LTS switch. When the WHT ON switch
is released, white-relay K2 remains energized
until either CAB & RAMP LTS switch or CABIN &
RAMP LIGHTS switch is set to ALL OFF.
3.
When either CAB & RAMP LTS switch is
momentarily set to RED ON, 28 vdc is applied
through a switch to terminal X1 of red relay
K1. The relay control circuit is completed to
ground through CABIN & RAMP LIGHTS switch.
Contacts A1-A2 provide a holding circuit for relay
K1. The holding circuit provides 28 vdc for relay
K1. When either switch is released, red relay K1
remains energized until either CAB & RAMP LTS
switch is set to ALL OFF.
4.
When the red lamps of the dome lights are on,
28 vdc is applied to the troop warning system to
dim the red and green jump lights.
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