Operation Of Arac System - Komatsu HM400-5 Operation & Maintenance Manual

MACHINE OPERATIONS AND CONTROLS
Explanation of components
(1) Automatic retarder, accelerator linked control
switch
(2) Retarder control lever
(3) Accelerator pedal
Automatic retarder, accelerator linked control switch
Automatic retarder, accelerator linked control switch is used to turn ON or OFF the ARAC system.
Retarder control lever
The retarder can be operated with the retarder control lever even while ARAC system is in operation.
REMARK
When the ARAC system is in operation, the retarder control lever has some play at the start of stroke.
It does not mean that the retarder brake does not work, but that it is the range of ARAC system operation.
Accelerator pedal
ARAC system functions only while the accelerator pedal is released.
Brake pedal
The wheel brakes can be operated with the brake pedal even while ARAC system is in operation.
Retarder pilot lamp
The retarder pilot lamp lights up when ARAC system operates and when the retarder is operated with the re-
tarder control lever.
(If the engine speed is low, even when ARAC system is actuated, the retarder pilot lamp may not light up.)

OPERATION OF ARAC SYSTEM

The ARAC system is actuated when the automatic retarder, accelerator linked control switch is turned to ON
position.
When the automatic retarder, accelerator linked control switch is turned to ON position, the retarder is automati-
cally actuated according to the travel speed and engine speed at that point.
If the accelerator pedal is depressed when the ARAC system is being actuated, actuation of the ARAC stops
and the machine speed increases.
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(4) Brake pedal
(5) Retarder pilot lamp
OPERATION