Komatsu 830E-AC Shop Manual page 197

24 VDC ELECTRIC CRANKING MOTOR
SYSTEM (WITH PRELUBE)
The Komatsu SDA16V160 engine includes an
engine pre-lubrication system designed to reduce
wear due to dry starts.
The prelube system automatically, safely and quickly
fills filters and all oil passages prior to cranking at
each engine startup. In addition, the system prevents
startup if no oil is present in the engine.
The prelube system includes:
• Remote mounted 24VDC powered pump
• Timer solenoid
• Oil pressure switch
• Oil suction line
• Oil outlet line
• Check valve
• Electrical harness.
FIGURE 2-3. PRELUBE MOTOR AND CRANKING MOTOR ELECTRICAL DIAGRAM
1. Battery Charging Alternator
2. Oil Pressure Switch (N.C.)
17.2 kPa (2.5 psi)
3. Prelube Timer Solenoid
D02034
Operation
The prelube system is activated when the operator
turns the key switch and holds it in the "start" posi-
tion. This allows the current to flow to the prelube
cranking motor solenoid timer (3). When this sole-
noid timer is activated, current flows through fusible
link (9) to the prelube motor (10), driving the prelube
pump, but does not allow the cranking motor motors
to engage the cranking motor pinion gears at this
time. The prelube pump supplies oil from the engine
oil pan to fill the engine oil filters and oil passages
prior to cranking.
When the pressure in the engine cam oil rifle reaches
17.2 kPa (2.5 psi), the circuit to the timer solenoid is
opened. After a 3 second delay, the current is sup-
plied to the cranking motor solenoids (8); the crank-
ing motor motors will then be activated and the pinion
gears will be engaged into the flywheel ring gear.
Normal cranking will now occur with sufficient lubri-
cation to protect the engine bearings and other com-
ponents.
4. Cranking Motor No. 2
5. Cranking Motor No. 1
6. Magnetic Switch
7. Diode (Coil Suppression)
24 VDC Electric Supply System
8. Cranking Motor Solenoid
9. Fusible Link (400 AMP)
10. Prelube Pump & Motor
11. Isolation Diode
D2-7