Komatsu Galeo PC138US-8 Shop Manual page 263

10 Structure, function and maintenance standard
Starting engine
When starting switch (5) is turned "ON", engine
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controller (6) sends command current to fuel
supply pump (14).
For this reason, a fail-safe mechanism is pro-
vided with the electrical system to stop the
engine when an electrical failure occurs.
When starting switch (5) is turned to "START"
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with lock lever (7) set in the "LOCK" position, a
starting current is supplied to starting motor
(13) causing the engine to start.
However, as the neutral safety mechanism is
provided, the engine will not start if lock lever
(7) is set in the "FREE" position at this time;
starting motor cut-out relay (9) cuts off the
starting current to starting motor (13).
Upon receipt of the engine cut-off command
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from the external source, KOMTRAX terminal
(19) sends the signal to machine monitor (18).
Machine monitor (18) causes starting motor
cut-out relay (10) to cut off the starting current
to starting motor (13), therefore the engine
does not start.
Engine speed control
Upon receipt of a fuel control dial (11) control
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signal, engine controller (6) sends a command
current to fuel supply pump (14) to adjust the
fuel injection amount to control the engine
speed.
Stopping engine
When starting switch (5) is turned "OFF", the
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current from the ACC terminal of starting
switch (5) to engine controller (6) is cut off, and
consequently the command current to fuel sup-
ply pump (14) is cut off.
Fuel supply pump (14) stops fuel feed, causing
the engine speed to go down and the engine
stops.
PC138US, USLC-8
SEN02553-01
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