Manitowoc 2250 Service Maintenance Manual

Reference Only
INTRODUCTION 2250 SERVICE/MAINTENANCE MANUAL
1-44
Published 07-19-16, Control # 249-01
Load Drum System—Full Power
General
See Figure 1-27, Figure 1-28, and Figure 1-29 for the
following.
The load drum system has two drive shafts where the three
load drums connect and disconnect to the drive shaft with
clutches. The front drum (drum 1) is on one drive shaft and
the split drums right rear (drum 2) and left rear (drum 3) are
on the second drive shaft. The two load drum pumps drive
one motor (dual load drum motors are optional). The two
pumps increase load drum speed and torque. In Standard
mode only, one drum can be operated at a time.
The load drum that is connected to the drum shaft is
determined either by the programmable controller (PC) or
the operator. The PC engages the last selected drum clutch
to the drum shaft and disengages the other clutches from the
drive shaft. The operator selects the desired load drum with
the load drum’s handle movement.
Depending on the crane’s load drum configuration, the left
load drum control handle on the right console normally
operates either the full front drum (drum 1) or right rear drum
(drum 2), while the right load drum control handle on the right
console normally operates either the full rear (drum 2) or left
rear drum (drum 3). See Operating Controls in Section 3 of
the Operator Manual for handle-to-drum identification.
When the crane is configured with two split rear drums, the
operator shall select the desired operating rear drum. If a
drum is not in use, the working brake pedal must be applied
and latched.
Hydraulic charge pressure from the system charge pumps
supplies hydraulic pilot pressure to operate the motor servo.
A pressure sender in the motor servo pilot pressure line
provides system pressure information to the PC.
A speed sensor at the load drum flange monitors rotational
speed and sends an input voltage to the PC. The PC sends
an output voltage to the rotation indicator in the control
handle. As the drum rotates faster, the rotation indicator on
top of the control handle pulsates to indicate the drum’s
rotational speed. The drum speed is also shown on the
selected drum display screen.
Continuous changing of the closed-loop fluid occurs with
leakage in the pump, motor, and external sequence/flow
valve. The sequence/flow valve opens when system
pressure exceeds 14 bar (200 psi) and removes 30 L/min
(8 gpm) of hot fluid from the system by dumping the fluid in
the motor case where the fluid returns to the tank through the
tank cooler.
Drum Brake
When a selected main hoist drum brake switch is in the ON
position, the drum brake solenoid valve to each drum is
disabled and the brakes are applied to the drum shaft. The
drum pump does not stroke in response to the control
handle’s movement.
When a selected load drum-brake switch is placed in the
OFF position, the brake solenoid valve to the drum remains
applied, waiting for a control handle command. The PC
controls the selected drum brake with movement of the
control handle when the drum is in the full power mode.
Hoisting the Load Drum
The following hoisting operation is for the right rear drum
(drum 2) with a three drum configuration, while operating in
full power mode. Operation of the other load drums is similar.
When the right load drum control handle is moved back for
hoisting, an input voltage of 5 V or more is sent to the PC.
The PC sends a variable minus 0 to 2.8 V output that is
applied to both load drum pumps’ electrical displacement
control (EDC). The PC sends a variable 0 to 2.19 V output
that is applied to the load drum motor’s pressure-control pilot
(PCP). The PC checks that the selected drum maximum bail
and block-up limit switches are closed and that there are no
faults in the air or hydraulic systems.
The PC sends a 12 V output signal to enable the front drum
clutch solenoid AS-8 and left rear drum clutch solenoid AS-
12. The valves shift to allow manifold air pressure to flow to
the clutch cylinders and compress the springs to release the
clutches from the drum shaft. The right rear drum clutch
RF-19
Main Air Manifold
Boom Hoist
Boom Hoist
Pawl In
AS-13
AS-14
Pawl Cylinder
P
P
E
A
E
A
Boom Hoist
Pawl Out
Boom Hoist
Drum Flange
AS-16 (luffing jib)
AS-15 (luffing jib)
(luffing jib)
(luffing jib)
(luffing jib)
(luffing jib)
FIGURE 1-26

Manitowoc 2250 Specifications

General

Brand	Manitowoc
Model	2250
Category	Construction Equipment
Language	English