Preventing Electrocution - Komatsu SK818-5 Operation & Maintenance Manual

PRECAUTIONS TO BE TAKEN WHEN WORKING

2.4.6 PREVENTING ELECTROCUTION

Digging operations near overhead electric lines are extremely dangerous and they may also cause death due to
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electrocution; for this reason, when working near overhead electrical lines, always respect the minimum safety
distances prescribed by the competent authorities and by the accident-prevention rules in force.
As far as underground long-distance lines are concerned, the minimum distance depends on the covering of the
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ducts in which the cables are laid.
The basic safety precautions to be taken to prevent this risk are the following:
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1 - Wear shoes with thick rubber or leather soles.
2 - Request the aid of another person who can warn you if the machine gets too close to the electric line.
3 - Operate at low speed.
4 - Learn what is to be done first in case of electrocution.
5 - Keep the phone number of the electricity company and of the nearest first aid station at hand.
If the work equipment accidentally gets entangled in the cables, the operator must remain still and must not lea-
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ve the cab until the electricity company has insulated the line.
When carrying out this kind of operations, warn everyone standing in the work area to keep at the minimum di-
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stance prescribed from the machine and the work equipment.
Ask the electricity company in advance what are the voltage of the cables and the minimum safety distance.
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The minimum distances from overhead lines can vary in the different countries, according to the climate
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and to the percentage of humidity in the air.
Indicatively, the distances shown in the table should be respected.
Cable voltage
1.0 kV (distribution line)
6,6 kV (2÷3 insulators)
33 kV (min. 3 insulators)
66 kV (min. 6 insulators)
154 kV (min. 10 insulators)
275 kV (min. 19 insulators)
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DANGER
Min. safety distance
5 m
5.2 m
5.5 m
6 m
8 m
10 m
RWA37380