Komatsu HM400-5, Operation & Maintenance Manual

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The automatic retarder and accelerator linked switch is used to
turn ON or OFF the ARAC (Automatic Retarder Accelerator
Control).
Position (A)
The automatic retarder, accelerator linked control system oper-
ates and the retarder pilot lamp lights up.
Position (B)
The automatic retarder, accelerator linked control system does
not operate.
AISS LOW SWITCH
NOTICE
During aftertreatment devices regeneration, the idle speed is set to rather high regardless of ON or OFF
of AISS LOW switch.
AISS LOW switch is used to switch the AISS functions.
AISS (Automatic Idling Setting System) adjusts the low idle
speed automatically depending on the engine coolant tempera-
ture and operating situations.
(A) AISS LOW switch ON
Use this switch position when fine start control is needed such
as when putting the machine into the garage.
The low idle speed is fixed to a rather low level.
REMARK
When the automatic warm-up is turned on, this switch position
stops it, and set a low idle speed to a rather low level.
(B) AISS LOW switch OFF
Use this switch position for the normal operation.
AISS function is actuated to produce the states described below.
• When the engine coolant temperature is low, this switch position automatically sets the idle speed to a high-
er level. (Automatic warm-up function)
• When the parking brake or retarder brake is applied, the idle speed is automatically set to a rather low level
in order to reduce fuel consumption when the machine is stopped.
REMARK
While the automatic warm-up is turned on, the idle speed is not set to low even if the parking brake or retarder
brake is applied.
For the automatic warm-up, see “AUTOMATIC WARM-UP FUNCTION (3-182)”.
OPERATION EXPLANATION OF COMPONENTS
3-99