CONTROLS AND OPERATION
LOAD WEIGHING SYSTEM
CENTRAL UNIT The central unit consists of the standard
elements (main printed circuit board, fuse, sockets, etc. and
the vertical programmed P.C. boards. It also contains the
A. By-Pass Key. Located at the bottom of the box it deacti-
vates the shut-off system. Meters, Iights and horn on
the control panels are indicating even with a deactivated
shut off system.
It is recommended that the system by-pass key
switch be used with care. Unwarranted use of
it to override the shut-off system can result in
loss of life, destruction of property and irre-
pairable damage to the crane. The key switch
can be used in overriding the system in case of
extreme emergency. The operator using the
key in extreme emergency should use sound
B . Fuse. A 2 amp fuse is located in central unit. It is used to
protect the load weighing system from electrical over-
Figure 2-14. Angle Meter and Control Panel
A. The Analog Meter. This meter indicates total load
moment. The meter scale IS divided into three color
coded segments GREEN, YELLOW and RED
representing APPROVED, CAUTION and PROHIBITED,
respectively. When the needle of the load moment
meter is in the red zone of the scale, the boom lowering
and hoisting controls are out of function by means of the
B. Program Selector Switches. Program selector switch A
IS on tab, switch B is on the bottom.
C. Electronic Beeper.
D. Shut-Off Light/Reset Button.
E. Load Moment Warning Light/Pre-Warning Light.
F. Test Button/Pilot Light.
G. Key Switch.
H. Horn On/Off Button.
Figure 2-13. Central Unit
ANGLE METER. This meter indicates boom angle from 0° to
The system by-pass key switch must be used to over-
ride the shut-off system when positioning the jib
(without load on the block) lower than rated angle for
CONTROL PANEL. This unit contains the following items