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Reference
Only
Manitowoc
Published 05-16-17, Control # 233-03
1-21
999 SERVICE/MAINTENANCE MANUAL
INTRODUCTION
1
BOOM HOIST SYSTEM OPERATION
See Figures
Boom hoist handle (1) is inoperable when boom hoist brake
(2) is applied. There is no output signal to boom hoist pump
EDC (3) and boom hoist pump (4) does not stroke.
The left travel charge pump supplies pilot pressure to the
boom hoist motor servo (5). Hydraulic charge pressure from
rear drum charge pump must be above 200 psi (14 bar) to
operate boom hoist drum pawl. Hydraulic pressure to
operate boom hoist brake is from low-pressure side of boom
hoist system. Pressure sender (6) in high-pressure side of
boom hoist closed-loop system provides system pressure
information to the PC.
When boom hoist drum rotates, boom hoist drum speed
encoder (7) sends an input signal to the PC. The PC sends
an output signal that enables rotation indicator (8) in boom
hoist handle. Rotation indicator on top of control handle
pulsates with a varying frequency that indicates rotational
speed of boom hoist drum. As drum rotates faster, the
indicator pulsates faster.
Continuous changing of closed-loop fluid occurs through
leakage in pump, motor, and external sequence/flow valve
(9). Sequence/flow valve opens at 200 psi (14 bar) and
removes 6 GPM (23 L/min) of hot fluid from system by
dumping the fluid into the motor case where fluid returns to
tank through tank cooler.
An orifice (10), across motor ports A and B allows for
smoother fluid flow.
Boom Hoist Brake and Pawl Switch
When boom hoist brake switch (2) is in on - park position,
boom hoist brake release solenoid HS-13 is disabled so
brake is spring-applied to drum. Boom hoist drum pawl in
solenoid HS-14 is enabled to keep pawl applied to boom
hoist drum. Boom hoist pump does not stroke in response to
boom hoist handle movement.
FIGURE 1-13
WA-01
8D
8
WB-10
WB-09
SELECT
CONFIRM
CRANE MODE
8T
0
0
8
WB-26
WB-33
DOWN SCROLL
UP SCROLL
WA-24
K1
F4
F8
PRESSURE TRANSDUCER
BOOM HOIST
SYSTEM FAULT
BUZZER
25A
25
OPERATING LIMIT
BEEPER
5A
5A
+
_
ENGINE
10A
5D
5A
F15
STOP
STOP
3
RUN
START
7
MS1
K1
5DA
8
8P1
50 AMP
CB7
SEAT SWITCH
WB-34
999CSM1-112
F12
3A
REGULATED 10V DC OUTPUT
RAISE
OFF
LOWER
BOOM HOIST HANDLE
WA-05
WD-18
WD-19
DIGITAL DISPLAY
HS
13
BOOM HOIST
3
8
3
1
3
6
WC-14
BOOM HOIST
B
A
EDC
WD-37
HS
15
BOOM HOIST PAWL OUT
WD-10
WC-09
3
3
3
11
3
2
3
12
3
7
BLOCK UP LIMITS
MAXIMUM BOOM
ANGLE LIMIT
RIN
WB-12
WE-29
BH
PCP
BOOM HOIST
MOTOR CONTROL
PUMP CONTROL
WD-29
ROTATION INDICATOR
BOOM HOIST
14
HS
BOOM HOIST PAWL IN
WD-36
DRUM BRAKE
BOOM HOIST
SPEED
ENCODER
F
A
B
D
DRUM SHAFT
PROGRAMMABLE
CONTROLLER
WD-05
WD-06
Summary of Contents for 999
Page 1: ...R e f e r e n c e O n l y Service Maintenance Manual Manitowoc 999 ...
Page 2: ...R e f e r e n c e O n l y ...
Page 4: ...R e f e r e n c e O n l y THE ORIGINAL LANGUAGE OF THIS PUBLICATION IS ENGLISH ...
Page 297: ...R e f e r e n c e O n l y ...
Page 298: ...R e f e r e n c e O n l y ...