Komatsu PC500LC-10R Shop Manual page 119

10 STRUCTURE AND FUNCTION
FUNCTION OF OVERHEAT PREVENTION SYSTEM
This system prevents overheating by reducing the pump load and by lowering the engine speed when the cool-
ant temperature or the hydraulic oil temperature become too high during operation in order to protect engine
and hydraulic components.
Operating condition
Hydraulic oil temperature:
Min. 95 °C
Operating condition
Coolant temperature:
Min. 100 °C
or
Hydraulic oil temperature:
Min. 100 °C
Operating condition
Coolant temperature:
Min. 102 °C
or
Hydraulic oil temperature:
Min. 102 °C
Operating condition
Coolant temperature:
Min. 102 °C
or
Hydraulic oil temperature:
Min. 102 °C
Operating condition
Coolant temperature:
Min. 105 °C
or
Hydraulic oil temperature:
Min. 105 °C
PC500LC-10R
Operation and remedy
Working mode: Travel
→
Engine speed: Kept as it is
Travel speed: Slower
Operation and remedy
Working mode: P, E, ATT-P, or ATT
mode
→
Engine speed: Kept as it is
Lowers the pump absorption torque
to reduce engine load according to
the torque control signal.
Operation and remedy
Working mode: P, E, ATT-P, or ATT
mode
→
Engine speed: Kept as it is
Lowers the pump absorption torque
to reduce engine load according to
the torque control signal.
Operation and remedy
Working mode: B mode
Engine speed: Kept as it is
→
Alarm monitor: Lights up
Lowers the pump absorption torque
to reduce engine load according to
the torque control signal.
Operation and remedy
Working mode: All modes
→
Engine speed: Low idle
Alarm monitor: Lights up
Alarm buzzer: Sounds
OVERHEAT PREVENTION SYSTEM
Condition to cancel
Hydraulic oil temperature: Max. 95 °C
→
When above condition is satisfied, it
is restored to the state before opera-
tion (automatic restoration).
Condition to cancel
Coolant temperature: Less than
95 °C
Coolant temperature: Less than
→
95 °C
When above condition is satisfied, it
is restored to the state before opera-
tion (automatic restoration).
Condition to cancel
Coolant temperature: Less than
102 °C
Coolant temperature: Less than
→
102 °C
When above condition is satisfied, it
is restored to the state before opera-
tion (automatic restoration).
Condition to cancel
Coolant temperature: Less than
102 °C
Coolant temperature: Less than
→
102 °C
When above condition is satisfied, it
is restored to the state before opera-
tion (automatic restoration).
Condition to cancel
Coolant temperature: Less than
105 °C
Coolant temperature: Less than
105 °C
→
Fuel control dial: Return to low idle
(MIN) position.
When above conditions are satisfied,
it is restored to the state before oper-
ation (manual restoration).
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