Engine Controls - Manitowoc 999 Service And Maintenance Manual

INTRODUCTION
999CSM1-102
D
350 psi
(24 bar)
3
1
A
Input B
G
F D
The travel motor servo is opposite of other system motors.
Travel variable displacement motors begin operation at
minimum displacement (low torque, high speed) and shifts to
maximum displacement (high torque, low speed) when
s t a r t i n g t o r q u e i s r e q u i r e d a n d b a c k t o m i n i m u m
displacement when in motion if load is below a preset
pressure. Depending on motor system, servo uses internally
or externally supplied pressure to perform the shifting
operation. Servo control fluid is supplied from high-pressure
line of motor port "A" or "B" and shifts shuttle valve (22) and
servo control valve (23) before entering servo cylinder (24).
Continuous changing of closed-loop fluid occurs through
leakage in pumps, motors, and loop flushing valves. Motor
case fluid drainage lubricates the motor and provides a re-
circulation of hydraulic fluid to control heat in closed-loop
system.
Motors also have an internal loop flushing (purge) system
that consists of control valve (29) and relief valve (30). Loop
flushing allows 6 GPM (23 L/min) of fluid at 350 psi (24 bar)
to be removed from main hydraulic circuit for added cooling
and purification.
1-8
Pump
A
C
4
21
17
18
16
18 16
2
21
4
17
19
20
E
B
Published 05-16-17, Control # 233-03
999 SERVICE/MAINTENANCE MANUAL
L2 M6
29
30
22
26
A
M7

Engine Controls

See engine manufacturer's manual for instructions.
The engine is started and stopped with engine key switch.
Use engine stop push button to stop engine in an emergency
only as all brakes spring-apply and any functions stop
abruptly.
Engine rpm is controlled with either the hand or foot throttle
and monitored with an AC magnetic sensor.
The PC and engine throttle interface controls and processes
engine information and displays the information on digital
display screen.
Crane speed depends on engine speed and control handle
movement in either direction from neutral.
Engine clutch lever must be manually engaged for normal
operation.
Three engine indicator lights: engine warning, engine
diagnostic, and engine maintenance are mounted on front
console.
Engine maintenance clear switch is provided to clear an
engine fault after fault is corrected.
Motor
M4 M3
Output
24
Max.
Disp.
27
T3
T2
26
23
T1
25
M8
FIGURE 1-3
M1
M9
M5
M2