Crane operation
11.1 Before operating the crane
Operating manual 3 302 819 en 11 - 15
GMK3060
13.12.2018
11.1.5 Earthing the load
Even if the truck crane is already earthed (Ã 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 earthing.
• Hammer a metal rod (4) (length of about 2.0 m
(6.6 ft)) at least 1.5 m (5 ft) into the ground.
• For better conductivity, dampen the soil around
the metal rod (4).
• Clamp an insulated cable (3) to the metal
rod (4) (cross-section of at least 16 mm
2
(0.025 inches
2
)).
• Clamp the other end of the cable (3) to a metal
rod (2) with an insulated handle (1).
• Hold the metal rod firmly by its insulated handle (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 switchgear
– 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 electri-
cally conductive. When earthing, hold the metal rod only by the insulated handle
and keep a sufficient distance to the metal rod in the ground.