Preventing Electrocution - Komatsu WB93S-5 F50003 Operation & Maintenance Manual

PRECAUTIONS TO BE TAKEN DURING WORK

2.4.7 PREVENTING ELECTROCUTION

Digging operations near overhead electric lines are extremely
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dangerous and they may also cause death due to 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
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minimum distance depends on the covering of the ducts in
which the cables are laid.
The basic safety precautions to be taken to prevent this risk are
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the following:
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 - Get acquainted with the behaviour rules to be followed in
case of electrocution.
5 - Keep the phone number of the electric energy company and
of the nearest hospital at hand.
If the work equipment gets accidentally entangled in the cables,
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the operator must not leave the cab until the electricity company
has insulated the line.
When carrying out this kind of operations, warn everyone
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standing in the work area to maintain a safety distance from the
machine and the work equipment.
Ask the electricity company in advance what are the voltage of
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the cables and the minimum safety distance.
The minimum distances from overhead lines can vary in the different countries, according to the climate
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and to the humidity percentage in the air.
Indicatively, the distances indicated in the table should be respected.
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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Cable voltage
DANGER
Min. safety distance
5 m
5,2 m
5,5 m
6 m
8 m
10 m
RKA16790