Komatsu 830E Shop Manual page 132

CRANKING MOTORS
OPERATION
Heavy duty batteries supply 24VDC to each of the
two cranking motors through magnetic switches acti-
vated by the key switch on the instrument panel.
Note: When a Komatsu SSDA16V160 engine with a
prelube system is installed, there is a delay between
the time the key switch is moved to the START
position, and the starter motors actuate.
When the keyswitch is placed in the "Start" position,
the magnetic switches close, connecting the motor
solenoid "S" terminals to the batteries. When the
solenoid windings are energized, the plunger (56,
Figure 2-8) is pulled in, moving the starter drive (71)
assembly forward in the nose housing to engage the
engine flywheel ring gear. Also, when the solenoid
plunger is pulled in, the main solenoid contacts close
to provide current to the motor armature and crank-
ing takes place. When the engine starts, an overrun-
ning clutch in the drive assembly protects the
armature from excessive speed until the keyswitch is
released. When the keyswitch is released, a return
spring causes the drive pinion to disengage.
After the engine is running, a normally closed pres-
sure switch senses engine oil pressure and opens
the electrical circuit to prevent actuation of the
motor(s) after the engine has started.
Removal
1. Disconnect battery power:
a. Open the battery disconnect switch to
remove power from the system.
b. Remove the battery cables using the follow-
ing sequence:
1.) Remove the battery positive (+) cables
first.
2.) Remove the negative (-) cables last.
2. Mark wires and cables and remove from motor
(2, Figure 2-6) and solenoid (3) terminals.
3. Remove motor mounting capscrews (1).
4. Remove motor assembly from flywheel housing.
D2-14
24 VDC ELECTRIC START SYSTEM
24 VDC Electric Supply System
FIGURE 2-6. CRANKING MOTORS
1. Mounting Capscrews
2. Cranking Motor
Installation
1. Align motor (2, Figure 2-6) housing with the fly-
wheel housing adaptor mounting holes and
slide into position.
2. Insert motor mounting capscrews (1).
3. Connect marked wires and cables to motor and
solenoid terminals.
4. Install in the following sequence:
a. Install the battery negative (-) cables first.
b. Install the battery positive (+) cables.
5. Close the battery disconnect switch.
3. Solenoid
D02023