B737点火系统维修手册英文翻译

The spark igniters are just forward of the fuel manifold, at the 4:00 position and the 8:00 position.

IGNITION - ENGINE COMPONENT LOCATION

IGNITION - FLIGHT COMPARTMENT COMPONENT LOCATIONS General

These components which control the ignition system are in the flight compartment: 1. Engine start switches 2. Ignition selector switch 3. Start levers. Component Locations

The ignition selector switch and engine start switches are on the forward overhead panel (P5).

The start levers are on the control stand.

IGNITION - FLIGHT COMPARTMENT COMPONENT LOCATIONS

IGNITION - IGNITION EXCITER

Purpose

The ignition exciters supply power to spark igniters. General

The ignition exciters change 115v ac to 20,000v dc. The output of the ignition exciter is 14.5 to 16 joules. The spark igniter uses this power to ignite the fuel/air mixture in the combustion chamber. Usually, only one ignition exciter per engine operates at a time. Physical Description

A 115v ac electrical connector attaches to the forward face of the ignition exciter. The ignition lead attaches to the aft face of the ignition exciter.

The ignition exciters attach to the fan case with four shockmounts. Each ignition exciter has a bond jumper that attaches to the engine. Training Information Point

WARNING: MAKE SURE THAT THE IGNITION EXCITERS ARE DE-ENERGIZED FOR A MINIMUM OF FIVE MINUTES BEFORE YOU START

WORK ON THE IGNITION SYSTEM. THE IGNITION SYSTEM VOLTAGE IS DANGEROUSLY HIGH. DO NOT TOUCH THE ELECTRICAL CONTACTS. THE IGNITION EXCITERS CAN HAVE AN ELECTRICAL CHARGE EVEN WHEN NOT ENERGIZED. IF YOU DO NOT OBEY THIS STEP, INJURY TO PERSONS CAN OCCUR.

IGNITION - IGNITION EXCITER

IGNITION - DISTRIBUTION - IGNITION LEADS AND SPARK IGNITERS Purpose

The spark igniters supply an electrical spark to ignite the fuel/air mixture in the combustion chamber.

The ignition leads transmit power from the ignition exciters to the spark igniters. General Description

Each spark igniter has its own ignition lead. Air goes around each ignition lead to decrease the temperature of the lead. Ignition Lead Cooling

Each ignition lead goes into an air manifold at the 6:00 position at the aft end of the fan case. Booster air (low pressure compressor exhaust air), makes each ignition lead cool. The booster air goes into the air manifold and moves around the inner part

of the ignition lead shroud. Booster air comes out of the spark igniter end of the ignition lead to cool the spark igniter. Spark Igniters

Each spark igniter installs into an adapter at the 4:00 and 8:00 positions on the engine. The spark igniter electrode is inside the combustion chamber.

IGNITION - DISTRIBUTION - IGNITION LEADS AND SPARK IGNITERS

IGNITION - FUNCTIONAL DESCRIPTION

General

These are the components that operate the ignition system: 1. Start levers 2. Engine start switches 3. Ignition selector switch 4. EEC.

The ac transfer bus 1 supplies 115v ac electrical power to the EEC for the left ignition exciter. The ac standby bus supplies 115v ac electrical power to the EEC for right ignition exciter. The left ignition exciter for engine 2 uses power from ac transfer bus 2. The right ignition exciter uses the ac standby bus.

The EEC controls power to the ignition exciters. Input from the flight compartment components give manual control. The EEC has internal logic for