Manitowoc 2250 Service Maintenance Manual

Reference Only
INTRODUCTION 2250 SERVICE/MAINTENANCE MANUAL
1-42
Published 07-19-16, Control # 249-01
Lowering the Boom Hoist/Luffing Jib
The following description is for the boom hoist system. The
luffing jib system is similar.
When the control handle is moved forward for booming
down, an input voltage of 5 V or less is sent to the PC. The
PC sends a variable plus 0 to 2.8 V output that is applied to
the pump’s EDC. The PC sends a variable 0 to 2.19 V output
that is applied to the motor’s PCP. The PC checks that all the
block-up limit switches are closed and that a system fault is
not present.
The pump’s EDC tilts the swashplate up to satisfy pressure
memory. The PC compares the boom hoist-holding pressure
to the pressure memory. When the system pressure is high
enough, the PC sends a 12 V output to the brake solenoid
valve HS-6. The brake solenoid shifts to block the drain port
and opens the port to pilot pressure from the boom hoist
charge pump to release the drum brake. When the brake is
released, the pump’s EDC continues to tilt the swashplate
down. Hydraulic fluid flows from the pump’s outlet port to the
motor’s inlet port. Return fluid is from the motor’s outlet port
to the pump’s inlet port.
The PC’s output voltage to the pump’s EDC and the PC’s
output voltage to the motor’s PCP are relative to the control
handle’s movement. As the control handle is pushed
forward, the pump’s swashplate angle is increased. When
system pressure exceeds the PCOR valve setting of 340 bar
RF-17
50 Amp
8P1
10 V Regulated Supply
WA-05
WA-01
Left Side Control Handle
K1
8
Raise
5A
F16
3A
Lower
F12
5A
8T
Crane Display
WD-19
WD-20
WC-14
Boom Hoist Pump
EDC
B
A
0
Ground
Boom Hoist
Pressure
Sender
WA-26
WA-20
WD-06
WD-05
Boom Hoist
Speed
Sender
F
A
B
D
(drum 4)
HS
6
Boom Angle
Indicator
87FA
WD-27
Rotation Indicator
Boom Hoist Brake
AS
14
AS
13
F8
15A
8S
WB-29
Boom Hoist Pawl In
Boom Hoist Pawl Out
Boom Hoist Brake
WC-09
5A
8E
WE-29
Boom Hoist Motor
PCP
B
A
WD-24
Luffing Jib Motor
PCP
B
A
HS
19
Luffing Jib Brake
WC-25
AS
16
AS
15
Luffing Jib Pawl In
Luffing Jib Pawl Out
Luffing Jib Brake
WB-30
WA-21
Luff. Jib Angle
Indicator
Luffing Jib
Pressure
Sender
WA-19
WD-02
WD-01
Luffing Jib
Speed
Sender
F
A
B
D
(drum 5)
F11
F10
5A
8D
WE-14Max. Boom/luffing Angle
Programmable
Controller
FIGURE 1-24

Manitowoc 2250 Specifications

General

Brand	Manitowoc
Model	2250
Category	Construction Equipment
Language	English