Manitowoc 2250 Service Maintenance Manual

Reference Only
Manitowoc Published 07-19-16, Control # 249-01 1-35
2250 SERVICE/MAINTENANCE MANUAL INTRODUCTION
1
When the drum 1, 2, or 3 load drum brake solenoid (AS-7,
AS-9, or AS-11) is disabled, pilot pressure is exhausted from
the brake relay. The brake relay valve closes, exhausting
sealing air from the quick-release valve’s diaphragms, to
exhaust air from the brake cylinders. The brake cylinder
springs apply the brakes.
Working (Service) Brakes
The working brake part of the cylinder chamber is controlled
with a selected drum working brake pedal. The working
brake relay shifts to allow manifold air flow to the working
brake cylinder chamber, compressing the spring and
applying the brake band against the drum.
Pressure applied by the brake is in proportion to the brake
pedal’s movement. Full brake application is obtained when
the brake pedal is applied and latched. When the brake
pedal is released, the working brake is released at the same
rate as pedal movement until completely released.
Load Drum Clutch Release System
Front or rear load drum clutches are air controlled and are
spring-applied/air-released. The PC controls the clutches
with air pressure switches and selected load drum control
handle movement, depending on mode and circuit
requirements. The PC monitors the air pressure switches
when the operator switches from one load drum to another.
The clutch and brake air lines are connected through the
shuttle valve to the pressure switch. The PC waits until the
pressure switch closes before stroking the pump and
releasing the selected drum brake.
When the circuit to the selected load drum clutch solenoid
AS-8, AS-10, or AS-12 is open, manifold pressure is blocked
and air is exhausted from the drum clutch cylinder. The
clutch spring applies to connect the drum shaft to the motor.
When a selected load drum control handle is moved, an
input signal is sent to the PC. The PC sends an output signal
to the clutch solenoid AS-8, AS-10, or AS-12. The PC selects
Pedal
M
M
M
F-12
Brake
Solenoid
Brake
Relay
Regulator
Working
Brake
Relay
Working
Brake
Not Used
Clutch
Cylinder
Brake
Cylinders
Quick
Release
Valve
AS7 (drum 1)
AS9 (drum 2)
AS11 (drum 3)
Quick
Release
Valve
Load Drum
Clutch
Valve
AS8 (drum 1)
AS10 (drum 2)
AS12 (drum 3)
FIGURE 1-19
8D
Pressure Switch
89V (drum 1)
89U (drum 2)
89R1 (drum 3)
Load
Drum
Drum
Flange

Manitowoc 2250 Specifications

General

Brand	Manitowoc
Model	2250
Category	Construction Equipment
Language	English