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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 turn the override key that is under the
left instrument panel, and swing the boom to a safer position.
If the load is the maximum for the load line 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. On the other hand, if the boom is fully raised (about 70°),
the RCL may show an overload condition because the pressure in the boom lift cylinder is
sensed to be an overload. To correct this condition, the override key may be turned & 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 key switch under
the dashboard may be required to move the boom.
W A R N I N G
We recommend the emergency override switch be used with discretion. Improper or
careless use of this switch can cause damage to the crane and endanger people and
property. The operator who uses the switch in an emergency should use good
judgment.
There is a light on the dashboard to warn that one or more outriggers is not fully extended
when using the ON OUTRIGGERS setup on the RCL. Check the light daily (when the
outriggers are down and when there is no load on the hook) by raising and lowering each
outrigger about three inches. The light should come on when an outrigger is up.
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