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APU FIRE EXTINGUISHING -APU FIRE EXTINGUISHING BOTTLE
WARNING: BE CAREFUL WHEN YOU MOVE THE FIRE EXTINGUISHING BOTTLE. THE FIRE EXTINGUISHING BOTTLE IS HIGHLY PRESSURIZED AND HAS AN EXPLOSIVE CARTRIDGE AS A COMPONENT. ACCIDENTAL DISCHARGE OF THE FIRE EXTINGUISHING BOTTLE CAN CAUSE INJURY TO PERSONS OR DAMAGE TO EQUIPMENT.
WARNING: STAY OFF THE CONTROLS BAY ACCESS DOOR, 313AL. YOUR WEIGHT CAN RELEASE THE SPRING-LOADED LATCHES. IF YOU FALL THROUGH THE DOOR, INJURIES WILL OCCUR.
EFFECTIVITY BEJ ALL 26-22-00
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APU FIRE EXTINGUISHING -APU FIRE EXTINGUISHING BOTTLE
EFFECTIVITY BEJ ALL 26-22-00
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D633W101-BEJ Jan 05/2002
APU FIRE EXTINGUISHING -APU FIRE BOTTLE SQUIB
Purpose
The squib releases the halon from the APU fire extinguishing bottle.
Location
The squib is in the discharge assembly at the bottom of the fire bottle.
Physical Description
The squib is an electrically operated explosive device. It is adjacent to a bottle diaphragm that can break. The diaphragm normally seals the pressurized bottle.
Functional Description
The squib fires when you operate the discharge controls. The explosion opens the diaphragm. Nitrogen pressure inside the bottle pushes the halon through the discharge port.
Training Information Point
You must replace the squib every 10 years. The service date is on one of the squib wrench flats. You can replace the squib without removing the fire extinguishing bottle.
WARNING: INSTALL THE PROTECTIVE COVER ON THE SQUIB WHEN THE AIRPLANE WIRING IS DISCONNECTED FROM THE SQUIB. FOLLOW THE INSTRUCTIONS IN THE COMPONENT MAINTENANCE MANUAL IF YOU NEED TO MEASURE THE SQUIB
RESISTANCE. INCORRECT PROCEDURES OR
EQUIPMENT COULD FIRE THE SQUIB AND
CAUSE INJURY.
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APU FIRE EXTINGUISHING -APU FIRE BOTTLE SQUIB
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D633W101-BEJ Jan 05/2002
APU FIRE EXTINGUISHING -CARGO FIRE/ENGINE CONTROL PANEL
Purpose
The cargo fire/engine control panel permits flight deck control of the APU and cargo fire extinguishing systems. The panel also permits control of the electronic engine control mode, engine ignition, and autostart.
Location
The cargo fire/engine control panel is in the flight deck on the P5 overhead panel.
Physical Description
The cargo fire/engine control panel has a fire switch for the APU and a discharge light for the APU fire bottle.
Quick release fasteners attach the module to the overhead panel structure. Electrical connectors connect the airplane wires to the panel.
EFFECTIVITY BEJ ALL 26-22-00
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APU FIRE EXTINGUISHING -CARGO FIRE/ENGINE CONTROL PANEL
EFFECTIVITY BEJ ALL 26-22-00
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D633W101-BEJ Jan 05/2002
APU FIRE EXTINGUISHING -APU FIRE SWITCH
Purpose
The APU fire switch gives an indication of an APU fire and controls the APU fire extinguishing system.
Physical Description
The APU fire switch includes these parts:
*
APU fire warning light
*
Solenoid
*
APU fire override switch
*
Push-pull switch contacts (internal)
*
Rotary switch contacts (internal).
The fire warning light uses three light emitting diodes (LEDs).
Location
The APU fire switch is on the cargo fire/engine control panel. That panel is on the P5 overhead panel.
Functional Description
The solenoid locks the fire switch so you cannot pull it accidently. If the APU has a fire, the fire warning light comes on and the solenoid energizes to release the switch.
When you pull the fire switch, the push-pull switch contacts isolate the APU from the airplane systems.
When the switch is out, you can rotate it left or right to a mechanical stop at the discharge position. The rotary switch contacts close and operate the fire extinguishing system.
When you release the switch, a spring moves the switch a small distance from the discharge position to open the rotary switch contacts.
The fire override switch lets you pull the fire switch when the solenoid is not energized.
You must put the switch back to the center position before you can push the switch in.
Training Information Point
The engine and APU fire switches are not interchangeable. The fire warning light labels and the electrical connectors are different.
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