Safety and Accident Prevention 2 2.12 Danger of falling objects 2.14 Working in the vicinity of overhead power lines Earth-moving machines are only to be used where there is a danger of falling objects if the operator’s stand has a canopy (FOPS). A front guard must be employed if there is a risk of materials breaking through into the cabin. If the earth-moving machine is being used in the vicinity of overhead power lines and trolley wires, a safety distance which varies depending on the nominal voltage of the overhead line must be maintained between the lines and the earth-moving machine and its work equipment, to prevent current overspill.
This also applies to the distance between these lines and attached implements or loads. In front of walls e. g. of stacked materials, earth- moving machines must be positioned and operated in such a way that the driver's seat and entry to the driver's seat are not situated on the side facing the wall. The safety distances specified below must be complied with. Demolition work is only to be performed by earth- moving machines where there is no danger to persons and if the machine is equipped with canopy, cabin-mounted front guard and the appropriate work implement. Observe the instructions and regulations valid in the user’s country.
2.13 Working in the vicinity of underground power lines In the observation of safety distances, all working movements of earth-moving machines, e. g. positions of the work equipment and the dimensions of attached loads must be taken into consideration. Uneven ground which would cause the earth-moving machine to be inclined and thus nearer to overhead lines must also be taken into account. Tab. 2 Prescribed safety distances Before commencing excavating work using earth- moving machines, it must be determined whether any underground power lines are present in the intended working zone which may present a danger to persons.
If underground power lines are present, their exact position and course must be determined in consultation with the proprietor or operator of the lines, and the necessary safety precautions decided and implemented. During work in windy conditions, both overhead lines and work equipment may swing out, thus reducing the safety distance. If it is impossible to maintain sufficient distance from overhead power lines and trolley wires, the plant operator must consult with the proprietor or operator of the overhead lines to find other safety precautions to prevent current overspill. Such measures could be, e. g.
The course of power lines in the work area must be clearly marked, under supervision, before commencing any excavation work. If the position of lines cannot be determined, search ditches must be dug - manually, if need be. Switching off the current, If underground power lines are encountered unexpectedly or they or their protective covers are damaged, the machine operator must discontinue work immediately and notify the supervisor.
Re-routing the overhead line, Cabling, or Limiting the operating zone of earth-moving machines 17/112 TL160 Operating Manual 12.9.08 Version 1.0 Nominal voltage in kV Safety distance meters – 1 1.0 >1 to 110 3.0 >110 to 220 4.0 >220 to 380 5.0 nominal voltage unknown 5.0