曝光台 注意防骗
网曝天猫店富美金盛家居专营店坑蒙拐骗欺诈消费者
Page 3
D633A101-GUN Feb 10/2003
BOEING PROPRIETARY - Copyright#- Unpublished Work - See title page for details.
737-600/700/800/900 AIRCRAFT MAINTENANCE MANUAL
26-17-00-001
General Description
These are the components for the wheel well fire detection:
* Main wheel well fire (overheat) sensing element
* Compartment overheat detection controller
* P7 glareshield panel
* Engine and APU fire control panel
* Aural warning unit.
Fire (overheat) sensing element in the main wheel well supplies
the wheel well fire detection signal. The signal goes to the
compartment overheat detection controller. This unit supplies
the fire alarms.
These are the flight compartment indications of a wheel well
fire:
* Two red FIRE WARN lights on P7 panel come on
* Bell sounds in the aural warning unit
* Red WHEEL WELL light on engine and APU fire control panel
comes on.
If the wheel well fire alarms come on due to a real fire or a fault,
the MAINT ADV light on the compartment overheat detection
controller comes on. Use the module to do a check for real
alarm or a fault condition.
You use the test switch on engine and APU fire control module
panel to the OVHT/FIRE position to do a test of the wheel well
sensing element. If the test passes, the indications in the flight
compartment are the same as for a real fire condition. If the test
fails, use the compartment overheat detection controller to
isolate the fault.
NOTE: During the wheel well fire test, the engine overheat, the
engine fire, and the APU fire systems also do a test.
FIRE PROTECTION - WHEEL WELL OVERHEAT DETECTION - GENERAL DESCRIPTION
EFFECTIVITY
GUN ALL 26-17-00
Page 4
D633A101-GUN Oct 10/2002
BOEING PROPRIETARY - Copyright#- Unpublished Work - See title page for details.
737-600/700/800/900 AIRCRAFT MAINTENANCE MANUAL
26-17-00-006
FIRE PROTECTION - WHEEL WELL OVERHEAT DETECTION - GENERAL DESCRIPTION
FIRE PROTECTION - WHEEL WELL OVERHEAT DETECTION - GENERAL DESCRIPTION
EFFECTIVITY
GUN ALL 26-17-00
Page 5
D633A101-GUN Feb 10/2003
BOEING PROPRIETARY - Copyright#- Unpublished Work - See title page for details.
737-600/700/800/900 AIRCRAFT MAINTENANCE MANUAL
26-17-00-006
Purpose
The overheat sensing elements monitor for high temperature
conditions in the main wheel well.
Physical Description
The sensing element has a single strand of nickel wire
embedded in insulation. The insulation is impregnated with a
salt compound and is in a tube. The sensing elements have
these components:
* Nickel wire
* Insulation
* Tube
* Electrical connector.
Location
The sensing element is in the ceiling of the left and right main
wheel wells.
The sensing element attaches to the ceiling of the wheel well by
quick-release fasteners.
Functional Description
The sensing element is a thermistor type with resistance
inversely proportional to temperature. As the element
temperature increases, the resistance decreases. If any
portion of the sensing element is above alarm temperature of
400F (205C), the element resistance decreases sharply. The
single wire in the center of the core is the power lead and the
outside tube is electrically grounded. The insulating resistance
of the core material decreases suddenly at the alarm
temperature. Current flows through the core material to
ground when alarm temperature is sensed.
Training Information Point
The minimum bend radius for the sensing elements is one inch
(2.5 cm). If possible, do not bend the element in a radius less
than three inches (8 cm).
Sensing elements are in clamps with color-coded bushings.
The element end brackets have collars that prevent the element
from twisting when the electrical connectors are put on.
CAUTION: DO NOT MAKE THE PERMITTED DENTS OR KINKS
STRAIGHT. DAMAGE TO THE TUBING CAN
OCCUR.
NOTE: Make sure there is at least 0.50 inch (1.5 cm) between
the element and the structure except at the mounting
clips.
FIRE PROTECTION - WHEEL WELL OVERHEAT DETECTION - OVERHEAT DETECTOR ELEMENT
EFFECTIVITY
GUN ALL 26-17-00
Page 6
D633A101-GUN Oct 10/2002
BOEING PROPRIETARY - Copyright#- Unpublished Work - See title page for details.
737-600/700/800/900 AIRCRAFT MAINTENANCE MANUAL
26-17-00-003
FIRE PROTECTION - WHEEL WELL OVERHEAT DETECTION - OVERHEAT DETECTOR ELEMENT
FIRE PROTECTION - WHEEL WELL OVERHEAT DETECTION - OVERHEAT DETECTOR ELEMENT
EFFECTIVITY
GUN ALL 26-17-00
Page 7
D633A101-GUN Feb 10/2003
BOEING PROPRIETARY - Copyright#- Unpublished Work - See title page for details.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：
737NGAMM5(62)
