GREER COMPANY
Crane Systems 4 of 35
OUTLINE OF OPERATION
EXTENSION SENSORSYSTEM COMPONENTS
•MicroGuard®Display Unit The extension sensor provides an increasing voltage
proportional to the extension of the boom. A cable
attached to the boom head provides a low current
electrical path for the A2B signal
•MicroGuard® Computer Unit
•Pressure Transducers
•Extension Reel with length and angle sensors PRESSURE TRANSDUCERS
•Anti 2-Block (ATB) switches
•Cables Two pressure transducers measure the pressure in
the boom hoist cylinder. The resultant Total Moment
signal is processed to provide a continuous display of
the load suspended below the point of lift.
•Installation/Operator Manuals
The MicroGuard®510System is intended to aid the
crane operator by continuously monitoring the load
and warning of an approach to an overload or Two-
Block condition. Crane functions are monitored by
means of high accuracy sensors. The system
continuously compares the load suspended below the
boom head with the crane capacity chart stored in the
computer memory. At approach to overload, the
system warns by means of audible and visual alarms.
The system can be configured to cause function kick-
out by sending a signal to function disconnect
solenoids.
ANTI TWO BLOCK (A2B)
A switch monitors the approach of the hookblock or
overhaul ball to the boom head. The switch is held in
the normal position until the hookblock or overhaul
ball raises a weight that is mounted around the hoist
rope. When the weight is raised, it causes the switch
to operate. The resultant signal is sent to the
computer via the extension reel causing the A2B
alarm to operate and function kick-out to occur.
FUNCTION KICK-OUT
DISPLAY Electrically operated solenoids disconnect the control
lever functions for boom hoist lower, telescope out,
and winch up whenever an overload or an A2B
condition occurs.
The operator is provided with a continuous display of:
•Rated Load
•Actual Load
•Bar Graph showing Percentage of Rated Load OPERATOR SETTABLE ALARMS
•Radius of the Load These alarms, when properly set by the operator,
define the operating range. This is achieved by
means of minimum and maximum angle, maximum
height, and/or maximum length. These alarms can be
programmed for each job site and allow the operator
to work in a defined area.
•Boom Angle
•Main Boom Length
•Working Area
•Crane Configuration
On-screen messages provide the operator with visual
warnings of conditions that occur during operation of
the system.
AREA ALARM
When set, this alarm permits the operator to define
the operating zone by only two set points. The use
of this method results in a greatly enhanced working
area, and also clearly defines the operating zone.
BOOM ANGLE SENSOR
Boom angle is measured by means of a high-
accuracy potentiometer/pendulum assembly that is
damped to prevent overswing. It provides a voltage
proportional to boom angle. The boom angle sensor is
mounted inside the cable extension reel assembly.
