Tadano GT-550E-2, Operation And Maintenance Manual

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AML (Overload Prevention
Device)
T038300E
24
AML (Overload Prevention Device) AML (Overload Prevention Device)
The AML operates properly only when it is
used exactly as instructed in this manual. If you
do not follow the specified AML and crane operat-
ing procedures, the crane could overturn or be
damaged, causing a serious accident. Be sure to
observe the following precautions for safe opera-
tion.
• Never perform any operation with the AML deac-
tivated.
• Place the crane on firm and level ground with
the outriggers extended and adjust the crane so
that it is level.
• Before starting operation, perform pre-opera-
tional checks on the AML to ensure that it is
operating properly.
• Always make sure that the actual outrigger ex-
tension width and the representation of the
outrigger extension width on the AML display
conform. Otherwise the crane may overturn.
• While the swing stop cancel switch is shifted to
OFF, swinging will not stop automatically even
if overloading occurs. The rated lifting capacity
may vary during boom swing, depending on the
outrigger extension width and the front jack
condition. When swinging the load to the area
allotted for smaller rated lifting capacities after
lifting it in the area allotted for greater rated lift-
ing capacities, pay attention not to overload the
crane after understanding the section “How to
Read Performance Data Plate”.
If the alarm buzzer sounds and the moment ratio
indication on the AML exceeds 100% while a
load is swung, stop swinging immediately. Then
lower the load or swing the boom back. (For the
specified values which trigger the alarm, see
“Configuration and Functions of the AML
System” section.)
• When the AML exceeds the specified value, the
alarm will sound intermittently. Slow the crane
operation and take great care. (For the specified
values, see the “Configuration and Functions of
the AML System” section.)
• Do not lift a load on the boom with the jib
mounted. If this must be done by unavoidable
reasons, a boom lift status, and not a jib lift sta-
tus, should be selected on the AML.
In this case, a precautionary warning is output
when the moment is below 75% and a limit warn-
ing is output when the moment is below 85%.
Remember that the warnings will be output earli-
er. (For the moment values corresponding to the
warning types, see the "Configuration and
Functions of the AML System".)
• Do not lift a single load using both the boom
and jib. If this must be done by unavoidable rea-
sons, a jib lift status, and not a boom lift status,
should be selected on the AML. (The figure
shows a 5° offset angle with the first jib section
extended.) Make sure that the mass of the load
(including the mass of the load handling de-
vices) is less than the specified rated lifting
capacity for the jib. If the load is left held up only
by the auxiliary wire rope when the main wire
rope is loosened, the load's center of gravity
moves to give an increased figure in moment
display. Take care to overloading.
WARNING
T50182
T23991
°