Manitowoc MLC650 Service Maintenance Manual

Reference Only
Manitowoc Published 09-09-16, Control # 229-09 5-27
MLC650 SERVICE/MAINTENANCE MANUAL HOISTS
5
55
Drum 4 Hoisting Operation
See Figure 5-14 and Figure 5-16.
To enable the control system to drive the drum 4 pump and
motors, the switches listed below must be in the stated
positions:
• Seat safety switch closed
• Drum 4 park switch in the OFF position
When the drum 4 joystick is moved in the hoist up direction, a
signal is sent to the IOLC33 control module via the controller
area network bus (CAN Bus) to ramp up the pulse-width
modulation (PWM) duty cycle to the A-side solenoid of the
pump 5 electronic displacement control (EDC). The PWM
signal is in proportion to the speed commanded by the
joystick. Increasing the PWM duty cycle increases the pump
swashplate angle, which increases the hydraulic flow from
the A-side of the pump. From the pump, the flow is routed to
the B-side of the right drum motor and the A-side of the left
drum motor.
A signal is sent to the IOLC34 control module via the CAN
Bus to ramp up the PWM duty cycle to the left motor and
right motor controllers. Increasing the PWM duty cycle
decreases the swashplate angle in each motor, which
increases the motor speed until the rotational speed is
maximized based on the pump flow.
The drum 4 motor speed sensor and pump 5 pressure
transducer (drum 4 psi) provide closed loop feedback to the
control modules. The control algorithm uses this feedback to
adjust the pump and motor flows while ramping up to, and
maintaining, the speeds commanded by the joystick Input.
Drum 4 Lowering Operation
See Figure 5-15 and Figure 5-16.
To enable the control system to drive the drum 4 pump and
motors, the switches listed below must be in the stated
positions:
• Seat safety switch closed
• Drum 4 park switch in the OFF position
When the drum 4 joystick is moved in the hoist down
direction, a signal is sent to the IOLC33 control module via
the CAN Bus to ramp up the PWM duty cycle to the B-side
solenoid of the pump 5 EDC. The PWM signal is in
proportion to the speed commanded by the joystick.
Increasing the PWM duty cycle increases the pump
swashplate angle, which increases the hydraulic flow from
the B-side of the pump. From the pump, the flow is routed to
the A-side of the right drum motor and the B-side of the left
drum motor.
A signal is sent to the IOLC34 control module via the CAN
Bus to ramp up the PWM duty cycle to the left motor and
right motor controllers. Increasing the PWM duty cycle
decreases the swashplate angle in each motor, which
increases the motor speed until the rotational speed is
maximized based on the pump flow.
The drum 4 motor speed sensor and pump 5 pressure
transducer (drum 4 psi) provide closed loop feedback to the
control modules. The control algorithm uses this feedback to
adjust the pump and motor flows while ramping up to, and
maintaining, the speeds commanded by the joystick input.

Manitowoc MLC650 Specifications

General

Brand	Manitowoc
Model	MLC650
Category	Construction Equipment
Language	English