Broderson IC-250, Operation And Maintenance Manual

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2-11
W A R N I N G
Vapors can be formed inside fuel tank and cause buildup of pressure that can result in
sudden expulsion of gasoline and gasoline vapors from the filler neck when the fuel
cap is removed from a hot tank. Remove cap slowly. Fuel spray may cause injury.
RATED CAPACITY LIMITER (RCL)
A rated capacity limiter is installed on the crane to assist the operator in estimating loads and
measuring load radii. Please read the RCL Operation Manual for complete instructions on
operation of the system. Following are some additional operating tips.
Always be aware that the RCL can stop boom movement at capacity load conditions and in
two-blocking conditions. Use good judgment in controlling the speed of boom movements to
prevent shock loads and swinging loads.
If the RCL system stops the crane movement there are various remedies that may be used to
restart operation. If the hook is two-blocked, it should be lowered using the hoist control, if
safe. The boom raise and telescope retract may also be used if this is safer. In some
unusual circumstances it may be necessary to swing the boom before lowering the load. If
you are sure this will not cause an overload, you can press and hold the CANCEL button on
the RCL control and swing the boom to a safer position.
If the load is the maximum for the loadline or attachment, the load should be set down in a
safe place using the hoist lower control and the load or attachment changed. Telescope
retract may also be used and swing may be used, if safe, as described in the preceding
paragraph. DO NOT USE THE BOOM RAISE CONTROL as this may increase the overload.
If the load is at the maximum allowable load radius, the boom can be raised or retracted to a
safe radius or the load may be lowered to a safe place using the hoist control. If the boom
extension is at its angle limit, the boom must be raised or the load hoisted down.
If the boom is fully lowered until it stops, (about 0°) the RCL will show an overload condition
because the boom lift pressure sensors cannot read a useful pressure in this condition. To
remedy this, raise the boom slightly. Or, if the boom is fully raised, (about 73°) the RCL may
show an overload condition because the trapped pressure in the boom lift cylinder is sensed
to be an overload. To correct this condition, the CANCEL button on the RCL control can be
pushed & held , and the boom lowered just slightly. Then check for other conditions before
lowering further.
If there is a malfunction of the RCL or Anti-Two-Block system that causes loss of boom
movement and cannot be remedied by the procedures above, the override keyswitch under
the dashboard may be required to move the boom.