OPERATOR'S MANUAL MAINTENANCE

Section C - Electrics
Basic System Operation
Pump Control for Each Mode
C-22 C-22
9803/9880-3
Pump Control for Each Mode
Operation
Fig 23.
The machine can operate in four different modes,
depending upon the type of work required
K Engine
Throttle Control ( T C-18). The pump output horsepower
is varied by means of a PWM signal to the pump control
solenoid valve which varies for each mode.
Tier III machines are required to reduce the "range band"
"X to Y" (pump milliamps)
K Fig 25. ( T C-24), to improve
engine stability dependant on specific factors which
include:
– Barometric Pressure
– Fuel Temperature
– Air Intake Temperature
– Air Conditioning
– Engine and Hydraulic Temperature
These conditions are monitored by ECU1. Engine power
and pump power are then varied to suit the operating
conditions.
Each of the above factors has a value calculated by ECU1
of between 0 and 1. All values are then calculated to give
a dynamic control factor (DCF) of 0 to 1 which will
determine the pump output power and will vary the pump
mA to suit.