09.2020
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2.6
Safety distance to underground power lines/water supply
Start working only after explicit approval or confirmation of the shutoff of the underground power
supply lines by the responsible authority.
Treat the underground power lines as live until shutoff has been confirmed in writing by the
responsible authority.
Pay attention to distances between underground supply lines and working position.
If necessary, consult a second person for observation.
Break off if in doubt.
Warning
Electrical energy and fire hazard!
Coming into contact with a direct or an indirect current flow caused by a voltage flash-
over or step voltage can be fatal.
Observe the following safety notes
:
- Start working only after explicit approval or confirmation of the shutoff of
the overhead power lines by the responsible authority.
- Treat the overhead power lines as live until shutoff has been confirmed in writing
by the responsible authority.
- Pay attention to distances between overhead lines and spray beam.
- If necessary, consult a second person for observation.
- Break off if in doubt.
Examples of hydraulic energy:
- Coming into direct contact with an overhead power line.
- If the safety distance is not maintained, an arc will form.
- An overhead power line comes down and a dangerous resistance area
forms in the ground around it.
The safety machines of the different national electricity grids react differently in the event of a
fault. One may not assume that the overhead power lines will be automatically and
permanently shut down after a short to earth. A resistance area develops around the machine
and/or the damaged overhead power lines
The necessary safety distance depends on the rated main voltage of the power lines.
- Safety distances to overhead power lines are listed exemplary in ISO 12480-1 and
OSHA Part 1926.
- These are benchmark values.
- The respective nationally prescribed safety distances must be observed.
- Exact information on nominal line voltage is provided by the power supply company.
Safety distances "X"
: ISO 12480-1 Cranes - Safe use
(B)
Low Voltage
:
(B)
Medium Voltage
: Safe Distance X = 3000 mm
(A)
High Voltage
:
X = 6000 mm
Safety distances "X"
: USA- Occupational Safety and Health Administration
OSHA Part 1926. 1408 and 1926. 1409)
Nominal line voltage
:
up to
350 kV
=> Safe distance
X = 6100 mm
above
350 kV
X = 15250 mm
Voltage
Minimum Safe Distance
Low Voltage
100V,200V
2.0m
High Voltage
6.6 KV
2.0m
