Manitowoc 2250 Service Maintenance Manual

Reference Only
INTRODUCTION 2250 SERVICE/MAINTENANCE MANUAL
1-80
Published 07-19-16, Control # 249-01
Tongue Cylinder Retract
When the tongue cylinder switch is held in the UP (retract)
position, an input signal is sent to the PC. A 12 V output
signal from the PC enables the tongue cylinder retract
solenoid HS-51. Internal pilot supply pressure of 14 bar
(200 psi) enables the selected spool to shift the tongue
cylinder solenoid valve. The crane’s PC sends an output
signal to shift the crane’s auxiliary system disable-relief valve
HS-12 to block the valve’s bypass. Accessory system
pressure increases to operate the accessory items.
Accessory system fluid enters the MAX-ER’s accessory
valve and flows to the free-flow check valve section of the
counterbalance valve, entering the rod end of the tongue
cylinder to start retracting the tongue cylinder. Fluid from the
piston end of the cylinder is blocked by the free-flow check
valve section of the counterbalance valve and flows through
the flow-restraining section that has a relief setting of 193 bar
(2,800 psi). Return hydraulic fluid then exits the
counterbalance valve and passes through the MAX-ER’s
accessory valve before returning to the crane’s hydraulic
tank through the return line. Release the tongue cylinder
switch to the OFF position to lock the tongue in position.
(2,200 psi)
207 bar (3,000 psi)
(2,000 psi)
Wheeled Counterweight Trailer
X
13,8 bar
(200 psi)
XX
X
C2C1
Stop Cylinders
From Mast
Stop Cylinders
To Mast
Mast
RM-06
Extend
Retract
Tongue Cylinder
HS50
HS51
Accumulator
MAX-ER Accessory Valve
T
To Jib Strut
Cylinders
Jib Strut
Cylinders
From
FIGURE 1-50
207 bar
(3,000 psi)
Pressure
Sender
Accumulator
Mast
152 bar
138 bar
Accessory
To Crane
Crane
Manifold
Suction
Aux
Fan
Valves
HS12
Valve
Disable-Relie
f
Auxiliary System

Manitowoc 2250 Specifications

General

Brand	Manitowoc
Model	2250
Category	Construction Equipment
Language	English