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| Illustration 1 | g00927630 |
(1) Lubricator for barring motor (2) Barring motor (3) Engine (4) Starting motor (5) Air start control valve (6) Air supply (7) Strainer (8) Air starting motor relay valve (9) Lubricator for the starting motor | |
Starting Motor
The air starting motor is a vane motor. The air starting motor is mounted on the right front side of the engine flywheel housing. An air start control valve is actuated by the engine control switch. When the engine start signal is given, the solenoid energizes. This allows air to flow through the air start control valve. Air flow through the air start control valve allows the air pressure to force the drive shaft for the air starter and the pinion to engage the flywheel ring gear. After the flywheel ring gear is engaged, a port opens. This port allows air to flow through an air starting motor relay valve and to the air starter motor. The air starter motor cranks the engine. The crank terminate relay de-energizes the air start solenoid. The engine is designed for starting air pressure of 861.9 kPa (125 psi). However, the engine can be started with as low as 551.6 kPa (80 psi).
Barring Group
The engine is equipped with an air-actuated barring motor. (This is also called a "slow roll motor".) The barring motor is mounted to the left front side of the flywheel housing. The barring motor uses air pressure to rotate the engine at 4 rpm to 6 rpm of 827.4 kPa (120 psi). The barring motor is interlocked with the air start system in order to prevent actuation of the starter motor when the barring motor is engaged. Air to the starter motor passes through the barring motor and to the air starting motor relay valve. When the barring motor is engaged, flow of the air to the air starting motor relay valve is blocked. This prevents accidental engagement of the starting motor when the barring motor is engaged. The barring motor is equipped with a manual engaging lever. The manual engaging lever has a locking motor in order to prevent accidental engagement of the barring motor when the engine is running.