Retard Speed Control (Rsc) Adjustment Dial; Retard Speed Control (Rsc) Switch - Komatsu 930E-4SE Operation & Maintenance Manual

Operator Cab And Controls - Section 32
Page 32-8

Retard Speed Control (RSC) Adjustment Dial

RSC adjustment dial (8, Figure 32-3) allows the
operator to vary the downhill truck speed that the
retard speed control system will maintain when
descending a grade. This function can be overridden
by the throttle pedal, retard lever, or brake/retard
pedal.
When the dial is rotated counterclockwise
toward this symbol, the truck will descend
a grade at lower speeds.
When the dial is rotated clockwise toward
this symbol, the truck speed will increase.
NOTE: Always refer to the grade/speed chart in the
operator's cab and follow the recommendations for
truck operation. DO
recommended MAXIMUM speeds when descending
grades with a loaded truck.
Throttle pedal position will override the RSC setting.
If the operator depresses the throttle pedal to
increase truck speed, dynamic retarding will not
come on unless the truck overspeed setting is
reached or the brake/retarder pedal is used. When
the throttle pedal is released and the RSC switch is
ON, dynamic retarding will come on at, or above, the
RSC dialed speed and will adjust the truck speed to,
and maintain, the dialed speed.
To adjust the RSC control, pull up switch (9) and start
with dial (8) rotated toward fastest speed while
driving truck at the desired maximum speed. Release
the throttle pedal to let the truck coast and turn the
RSC adjusting dial slowly counterclockwise until
dynamic retarding is activated. Dynamic retarding will
now be activated automatically anytime the "set"
speed is reached, the RSC switch is on, and the
throttle pedal is released.
NOT exceed these
With the RSC switch on and dial adjusted, the
system will function as follows:
As the truck speed increases to the "set" speed and
the throttle pedal is released, dynamic retarding will
apply. As the truck speed tries to increase, the
amount of retarding effort will automatically adjust to
keep the selected speed. When the truck speed
decreases, the retarding effort is reduced to maintain
the selected speed. If the truck speed continues to
decrease to approximately 5 kph (3 mph) below the
"set" speed, dynamic
automatically. If the truck speed must be reduced
further, the operator can turn the dial to a new setting
or depress the brake/retarder pedal.
If the operator depresses the foot operated retard
pedal and the retard effort called for is greater than
that from the automatic system, the foot pedal retard
will override RSC.

Retard Speed Control (RSC) Switch

Retard speed control switch (9, Figure 32-3) turns
the system on and off. Push the knob in for OFF and
pull the knob out to turn the system ON.
8/11 OM3245
retarding will turn off