Only with wire rope
hoists
The wire rope hoist has an overload protection feature.
Depending on the type, the load of the fixed point crosshead is directly or
indirectly measured, or the motor current of the hoist drive is recorded during
lifting.
This allows the overload protection to measure the suspended
load and ensures that the wire rope hoist cannot lift any load which exceeds the
maximum load capacity.
In addition, the overload protection has a protective device
to prevent lifting the load with a sudden jolt (sudden load increase).
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Danger from falling suspended load!
Despite this overload protection, the crane could
be damaged by a load that is too heavy, causing the load to fall, killing
or injuring people.
Despite the overload protection, do not exceed the
maximum load capacity of the crane! |
If the wire rope hoist no longer lifts with the button
pressed:
● The
overload protection has triggered. The crane is now loaded with over 110% of its
maximum load capacity.
● With load
display: The load display flashes.
● With horn:
The horn sounds.
Release the ‘Lift’ button.
Press the ‘Lower’ button for at
least 2 seconds and set down the load.
● With
ABUControl: For 10 seconds only slow lifting speed can be used for lowering.
This prevents the crane from rocking with overload at fast lifting speed.
If the wire rope hoist briefly halts when lifting a load:
● The
overload protection has detected lifting with a sudden jolt (sudden load
increase).
● The wire
rope hoist lifts for 3 seconds only at slow lifting speed.
Continue to hold the 'Lift'
button completely pressed (stage 2).
● After 3
seconds, the wire rope hoist accelerates again to the fast lifting speed.
Only for wire rope hoists
with ABUControl
If the wire rope hoist no longer lifts and lowers:
● The crane
is now loaded with over 130% of its maximum load capacity.
● The wire
rope hoist blocks lifting and lowering.
To set down the load, the
overload protection must be temporarily bypassed.
See the ABUControl Product Manual.
Only with ABUControl and
crane with two trolleys
In joint operation of two trolleys on a crane, the overload
protection of both trolleys is jointly evaluated.
If the hoist of one of the trolleys is overloaded, the other
trolley is stopped simultaneously.
If the overload protection of one of the hoists has triggered in
individual operation:
● The
overloaded hoist can only be used to lower the load.
This enables a load slung on one or both hoists to be safely set
down.
● In
addition, the other hoist can only be used for lifting.
This ensures that with a load which is slung on both hoists and
has overloaded one of them, the load will not be lowered with the other hoist.
That would further overload the already overloaded hoist.
By lifting a load (which is slung on both hoists) with the other
hoist, the overloaded hoist can be relieved.
If the overload protection of one of the hoists has triggered in
joint operation:
● Only
lowering is possible with both hoists.
This enables a load slung on both hoists to be safely set
down.
If the overload protection for the total load has triggered in
individual operation:
● The
overloaded hoist can only be used to lower the load.
This enables the load slung on one or both hoists to be safely
set down.
In addition, the crane cannot be further overloaded.
● The other
hoist can be used neither for lifting nor lowering.
If the overload protection for the total load has triggered in
joint operation:
● Both hoists
can only be lowered in joint operation.
This enables a load slung on both hoists to be safely set
down.
This ensures that the crane cannot be further overloaded.
Only with chain hoists
The chain hoist has a special overload protection (friction
clutch). This ensures that the chain hoist cannot be used to lift loads that
could cause direct mechanical damage to the chain hoist. It also prevents damage
to the chain hoist if the load hook in the highest hook position knocks against
the housing from below.
Nevertheless, do not exceed the maximum load capacity of the
chain hoist!
If the load hook no longer moves, but the chain hoist is still
running:
● The
friction clutch has engaged.
Release the ‘Lift’ button.
Press the ‘Lower’ button and set
down the load.
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Danger from falling suspended load!
Moving to the highest hook position permanently
damages the friction clutch. This could cause the load to fall, killing or
injuring people.
Never run the load hook so far up that the
friction clutch engages. |