Manitowoc 14000 Service Maintenance Manual

Reference Only
INTRODUCTION 14000 SERVICE MANUAL
1-36
Published 09-05-14, Control # 226-02
Lowering Load
See Figures 1-19 and 1-20.
When drum 1 control handle is moved forward for lowering,
an input voltage of 2.6 volts or more is sent to node 1
controller. Node 4 controller sends a variable 0 to 24 volt
output that is divided by resistors and applied to pump 4 EDC
in raising direction. Node 3 controller sends a variable 0 to
24 volt output that is applied to motor PCP. Node 1 controller
checks that all limit switches are closed and that no system
faults are present.
Pump EDC tilts swashplate in the raising direction to satisfy
pressure memory. Node 1 controller compares drum holding
pressure to value in pressure memory. When system
pressure is high enough, node 3 controller sends a 24 volt
output to enable drum 1 brake release solenoid HS-1. Drum
brake solenoid shifts to block drain port and opens port to
low-pressure side of drum 1 system to release brake from
drum shaft.
Pump EDC tilts swashplate in the lowering direction as
hydraulic fluid flow is from pump outlet port A to motor inlet
port. Return fluid is from motor outlet port to pump inlet port
B.
Node 4 controller output voltage to pump EDC and node 3
controller output voltage to motor PCP is relative to control
handle movement. As control handle is moved back, an
output voltage increases pump swashplate angle.
When system pressure exceeds the ECOR (Electric
Compensating Over-Ride) valve setting of 3600 psi (248
bar), the valve shifts to direct flow from shuttle valve into
maximum displacement side of servo cylinder. The ECOR
valve over-rides the command from servo PC valve,
increasing motor displacement and output torque and
reducing output speed. When ECOR valve closes, control of
the motor returns to servo PC valve.
Node controllers continuously balance drum system
pressures and monitor motor displacement angle so motor
displacement goes to minimum when control handle is fully
forward, if motor torque requirements is not too high. Node 1
controller monitors motor displacement and controls motor
speed by regulating hydraulic fluid flow through the pumps.
When drum 1 control handle is moved toward neutral
position, node 1 controller compensates for hydraulic system
leakage or changing engine speed. This shifts motor back to
maximum displacement for slower output speed to slow
drum rotation.
When drum 1 control handle is moved to neutral position,
node 4 controller sends a zero output voltage to pump EDC
that moves swashplate to center position. Node 1 controller
stores load holding pressure in pressure memory. After
control handle center switch opens, node 3 controller sends
a zero output to disable drum 1 brake release solenoid HS-1.
Drum brake solenoid valve shifts to block pilot pressure to
brake and opens a line to tank. When brake applies, an input
signal is sent to node 1 controller. Node 4 controller sends a
zero volt output to pump EDC to de-stroke pump.
FIGURE 1-20
X
X
X
Suction
Manifold
Drum 1 Pump #2
Raise Load
Lower Load
350 psi
(24 bar)
Drum
Brake
Drum 1
Opens at 200 psi (14 bar)
Pressure
Sender
.060
Equalizing
Line
HS-1
4 g/m 15 L/m
Accessory System
Pressure Sender
To Accessory System
Components
14CSM1-113
B
A

Manitowoc 14000 Specifications

General

Brand	Manitowoc
Model	14000
Category	Construction Equipment
Language	English