Reference
Only
Manitowoc
Published 05-16-17, Control # 233-03
1-39
999 SERVICE/MAINTENANCE MANUAL
INTRODUCTION
1
The PC requires that auxiliary drum pump strokes in hoist
direction to satisfy pressure memory. The PC compares
auxiliary drum holding pressure to value stored in pressure
memory.
When system pressure is high enough, the PC sends a
positive output signal to enable brake release solenoid HS-
26. Brake release solenoid HS-26 shifts, to block tank port
and open port from low-pressure side of closed-loop to
auxiliary drum brake cylinder spring, releasing auxiliary drum
brake (7).
The PC sends a positive output voltage to enable auxiliary
drum pump EDC that tilts pump swashplate to stroke pump
in the hoist direction. Hydraulic fluid flows from auxiliary
drum pump port A to port A of auxiliary drum motor. Fluid
from motor port B returns to drum pump port B.
The PC controls raising speed by varying the voltage to
pump EDC and motor PCP in relation to auxiliary drum
handle movement. As handle is moved back, the PC sends a
signal to increase the pump swashplate angle. The PC also
sends a signal to reduce the displacement of the motor.
The PC is continuously balancing the system pressure and
the motor displacement angle so the motor displacement
goes to minimum when handle is all the way back, if the
to r qu e o n t h e m o t or i s no t t o o h i gh . K no w i ng th e
displacement of the motor, the PC may then control the
speed that the motor turns by regulating the flow through the
pump.
When auxiliary drum handle is moved to neutral position, the
PC sends an output signal to auxiliary drum pump EDC to
decrease the swashplate angle, reducing oil flow output.
This shifts the motor back to maximum displacement for
slower output speed to slow the drum rotation.
The PC stores the load holding pressure in pressure
memory. After control handle neutral switch opens, the PC
sends an output signal to disable brake release solenoid HS-
26 to spring-apply brake before auxiliary drum pump de-
strokes.
Auxiliary Drum Lower
See Figures
When auxiliary drum handle (1) is moved forward to lower,
handle neutral switch closes, sending an input voltage of 5
volts or less to PC. The PC sends a positive output voltage to
auxiliary load drum system pump EDC (2) and a positive
voltage to motor PCP (6). The PC checks that drum block-up
limit switches (12) are closed with no hydraulic system faults
present.
The PC sends a positive output signal to stroke the auxiliary
drum pump momentarily in the up direction to satisfy
pressure memory. The PC compares auxiliary drum holding
pressure to value stored in pressure memory.
When system pressure is high enough, the PC sends a
positive output signal to enable brake release solenoid HS-
26. Brake release solenoid HS-26 shifts, to block tank port
and open port from low-pressure side of closed-loop to
auxiliary drum brake cylinder spring, releasing brake (7).
The PC sends a positive output signal to enable auxiliary
drum pump EDC that tilts pump swashplate to stroke pump
in the lowering direction. Hydraulic fluid flows from pump port
B to port B of motor. Fluid from motor port A, returns to load
drum pump port A.
The PC controls lowering speed by varying the voltage to
pump EDC and motor PCP in relation to auxiliary drum
handle movement.
As handle is pushed forward, the PC sends a signal to
increase the pump swashplate angle. The PC also sends a
signal to reduce the displacement of the motor.
The PC is continuously balancing the system pressure and
the motor displacement angle so the motor displacement
goes to minimum when handle is all the way back, if the
t or qu e o n t h e m ot o r is n ot to o h i gh . K no w i ng t he
displacement of the motor, the PC may then control the
speed that the motor turns by regulating the flow through the
pump.
Содержание 999
Страница 1: ...R e f e r e n c e O n l y Service Maintenance Manual Manitowoc 999 ...
Страница 2: ...R e f e r e n c e O n l y ...
Страница 4: ...R e f e r e n c e O n l y THE ORIGINAL LANGUAGE OF THIS PUBLICATION IS ENGLISH ...
Страница 173: ...R e f e r e n c e O n l y Manitowoc Published 05 16 17 Control 233 03 4 19 999 SERVICE MAINTENANCE MANUAL BOOM 4 ...
Страница 174: ...R e f e r e n c e O n l y BOOM 999 SERVICE MAINTENANCE MANUAL 4 20 Published 05 16 17 Control 233 03 ...
Страница 297: ...R e f e r e n c e O n l y ...
Страница 298: ...R e f e r e n c e O n l y ...