Safety Near Electrical Wiring

Ensure safety when working near electrical wiring, such as overhead lines and cables. Accidents can be avoided by acknowledging safety instruction intended for the situation and familiarising yourself with instructions for situations involving damaged electric wiring.

Safety distances

Low voltage wire Medium voltage wire Power line

 

Voltage (volts V) Safety distance (metres m)
  open wire pendent cord
  below sides
0,4 kV* 2* 2* 0,5**
20 kV 2 3 1,5
110 kV 3 5 -
220 kV 4 5 -
400 kV 5 5 -

* Low voltage 0.4 kV open wires are rare these days.
** The distance also applies to 1 kV pendent cords.
1 kV = 1000 V

Information on recognising different wires used in the electrical network can be found here.

Safety Instructions

  • Always make sure in advance that you know where all the overhead lines and underground cables in the working area are located.
  • Contact the electricity company operating in the area to obtain working instructions and permits, and if necessary, underground cable showing or help logging down trees.
  • Situate storage facilities and loading places far enough from wires and cables and plan transportation routes in advance.
  • Keep safety distances.
  • Instruct all workers and especially machinery operators.

Excavation work

  • Make sure well in advance that you know where all the underground cables in the working area are located. You can get information on the location of cables from Johtotieto Oy the Safe-to-Dig service or the electricity company operating in the area.
  • Get an up-to-date cable map.
  • Contact the electricity company and ask for instructions and a cable showing, if necessary.
  • Always approach cables with caution and first locate/reveal them using suitable hand tools. Never move a cable on your own.
  • If unexpected cables are revealed during digging, immediately notify the electricity company and ask for instructions.
  • Also take any overhead lines and pylons into account.

If you hit an underground cable

  • Immediately get away from the damaged part of the cable by jumping with both feet next to each other or with only one foot on the ground at a time. The damaged cable may have a current running through it or a current my return to it.
  • Move the excavator bucket away from the excavation.
  • Immediately contact the electricity company even if the cable is not visibly damaged.
  • Make sure that outsiders cannot go near the excavation.

Working with machinery near overhead lines

  • Contact the electricity company well in advance of starting work.
  • Keep safety distances!
  • No part of a machine or load should breach the safety distances, even accidentally.
  • Estimating distances may be difficult. Keep a far greater distance to cables and wires than a visual estimate would suggest is required.

If you hit a cable

You are initially safe inside a vehicle.

  • Try to drive the vehicle away from the cable.
  • If the vehicle catches fire or the tyres are smoking jump out of the vehicle with both feet at the same time.
  • Get away from the vehicle by jumping with both feet next to each other or with only one foot on the ground at a time.
  • Do not touch the vehicle and the ground at the same time.
  • The safe area starts from about 20 metres from the site of the accident.
  • Immediately contact the electricity company even if the cable is not visibly damaged.
  • Make sure that the site of the accident is guarded.

Farm work

  • The pylon area of power lines covers a 3-metre radius from pylon structures above ground and the structures also go underground. Do not work with farm equipment or excavators within 3 metres of pylons or stay cables.
  • The safety distance to medium and low voltage wire pylon and support structures should be at least 1 metre.
  • Be careful not to accidentally hit pylon or support structures. Pylons may fall and take cables with them.
  • Make sure that covers used for protecting plants and equipment are properly fastened! A cover flown into cables by wind may cause damage to the power-distribution network. Do not remove covers hanging from cables yourself. Notify the electricity company without delay.
  • Report any damage to pylons, earth conductors or support structures to the electricity company without delay, even if the damage is small.

Taking down trees

  • Do not take down trees near power cables without instruction from the electricity company. Trees conduct electricity. Electricity can jump – a direct connection with a cable is not always required.
  • Ask the electricity company for help with removing trees in advance!
  • Make sure that the tree falls away from power lines.
  • Get familiar with safety requirements for logging.

If a tree falls onto a cable

  • Stop working immediately.
  • Do not try to remove the tree that is caught in the cable. Do not touch the tree or the cable.
  • Immediately get away from the tree by jumping with both feet next to each other or with only one foot on the ground at a time. The tree may have a current running through it or a current my return to it.
  • Notify the electricity company.
  • In case of a bodily injury, call 112.

Get familiar with safety requirements for removing trees in the guide Raivaajan käsikirja.

Storage near power lines

  • Situate storage facilities and loading places far enough from power lines and cables. Storage too close to power lines or cables is dangerous.
  • Also plan transportation routes in advance.
  • Take working distances into account.
  • A safe distance for working with long timber is at least 10 meters from cables.
  • The electricity company operating in the area provides information on sufficient storage distances.