Manitowoc GROVE GMK 6400, Operating Manual

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Crane operation
11.1 Before operating the crane
11 - 12 3 112 993 en Operating manual GMK 6400
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2
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7.
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11.1.5 Earthing the load
Even if the truck crane is already earthed (
à
p. 12 - 13), the load may
become charged with static electricity. For example, if a hook block with
synthetic sheaves or non-conducting sling gear is used.
Use electrically conducting material for earth-
ing.
•
Hammer a metal rod ( 4 ) (length approx.
2.0 m [6.6 ft]) at least 1.5 m (5 ft) deep into
the ground.
•
Dampen the soil around the metal rod ( 4 ) for
better conductivity.
•
Clamp an insulated cable ( 3 ) to the metal rod
( 4 ) (cross-section of at least 16 mm
2
[0.025 in
2
]).
•
Clamp the other end of the cable ( 3 ) to a
metal rod ( 2 ) with an insulated grip ( 1 ).
•
Hold the metal rod by the insulated grip ( 1 ).
•
To earth, touch the load with the metal rod.
B
Risk of accident due to electric shock
Always earth the load before operating the crane:
– Near strong transmitters (radio transmitters, radio stations, etc.)
– Near high-frequency switchgears
– If a thunder storm is forecast
If the load is charged with static electricity, you must always earth the load
before touching it.
B
Risk of accident due to electric shock
Ensure that the connections between the cable and the metal rods are elec-
trically conductive. When earthing, hold the metal rod only by the insulated
handle and keep a sufficient distance to the metal rod in the ground.