Manitowoc 2250 Service And Maintenance Manual

Reference Only
Manitowoc Published 11-06-15, Control # 040-13 1-85
2250 SERVICE/MAINTENANCE MANUAL INTRODUCTION
1
Jack Cylinder(s) Retract
When selected left, right, center, or all switch is held in the
DOWN retract position, an input signal is sent to the PC. A
12-volt output signal from PC enables the jack cylinder
retract solenoid HS-45, HS-47, and/or HS-49. Internal pilot
supply pressure of 200 psi (14 bar) enables spool to shift the
selected jack cylinder solenoid valve(s). Internal sequence
valve and shuttle valve for each spool valve controls each
system pressure when more than one valve is operated at a
time. The crane PC sends an output signal to shift crane
auxiliary system disable valve HS-12, to block valve bypass.
Accessory system pressure increases to operate accessory
items. Accessory system fluid enters MAX-ER accessory
valve and flows to free-flow check valve section of
counterbalance valve. Fluid pressure on rod end of the
selected jack cylinder retracts jack cylinder to lower the
counterweight trailer.
Fluid from piston end of jack cylinder is blocked by free-flow
check valve section of counterbalance valve and flow
restraining section of relief valve preset for a relief setting of
2,000 psi (138 bar). Piston end cylinder pressure opens
restraining section of counterbalance valve, allowing fluid to
exit valve. Return hydraulic fluid then passes through MAX-
ER accessory valve before returning to crane hydraulic tank
through return line.
When jack cylinder is retracted the desired distance, release
selected jack switch to OFF to lock jack cylinder(s) in
position. Trapped hydraulic pressure at piston end of jack
cylinder counterbalance valve supports the weight and
gravity force of counterweight trailer.
RM-07
54MB
54MA
8K
54MRB
54MRA
54MCB
54MCA
54MLB
54MLA
POWER
HS
44
HS
45
HS
48
HS
49
HS
46
HS
47
HS
41
HS
40
CB
8K
89J4
89K4
0
15 AMP
5A
LEFT JACK EXTEND
LEFT JACK RETRACT
CENTER JACK RETRACT
CENTER JACK EXTEND
RIGHT JACK EXTEND
RIGHT JACK RETRACT
ALL JACK RETRACT
ALL JACK EXTEND
COUNTERWEIGHT STRAP
CYLINDER RETRACT
MAX-ER 2000 REMOTE
COUNTERWEIGHT STRAP
CYLINDER EXTEND
HS
12
FIGURE 1-52
89H4
MAX-ER 2000
PROGRAMMABLE
CONTROLLER
AUXILIARY SYSTEM
DISABLE VALVE
CRANE
PROGRAMMABLE
CONTROLLER
88S

Manitowoc 2250 Specifications

General

Brand	Manitowoc
Model	2250
Category	Construction Equipment
Language	English