Contact with electricity can kill, cause serious burns and disabling injuries. There are many electrical incidents which damage equipment and thousands of ‘near-misses’, any of which could have had fatal consequences.
In agriculture, many of these involve contact with overhead power lines (OHPLs). Farm machinery is getting bigger and taller, increasing the chances of a cable strike. Such incidents also cause disruption and costs to farmers, other businesses and the community.
Others involve poorly maintained hand-held equipment, electrical faults on machinery or extension cables. Poor electrical installations and equipment can also cause fires, resulting in significant losses in buildings, equipment and livestock.
What you need to do...
Electrical equipment must be safe, and properly maintained. Work near electrical equipment, or conductors such as OHPLs should be carried out safely. You should isolate the power supply before carrying out any repair or maintenance work. The key issues are:
Overhead power lines
Electricity can arc (jump gaps) in certain circumstances when equipment or machinery gets close enough – you do not need to contact OHPLs to receive an electric shock. Make sure you know where OHPLs are located on your farm, or where you are required to work. For example, obtain a map showing the routes of the lines , available from your Distribution Network Operator (DNO), or mark the route of the lines on your own farm map. Ensure that visiting workers such as contractors also have copies and include details of OHPLs in contracts you have with them.
The safest option is to avoid OHPLs altogether if you can. But if you have to work near OHPLs, plan the job carefully and use safe systems of work.
Consult with your DNO and if necessary arrange temporary disconnection. If OHPLs run across your land, ask your DNO if they can be re-routed, put underground, or raised.
Risks can be reduced if the following activities are not carried out within a horizontal distance of at least 10m from OHPLs .
- stacking materials eg bales, fertiliser bags, or potato boxes etc
- erecting temporary structures eg polytunnels
- folding sprayer booms
- tipping trailers or lorries with tipping bodies
- operating materials handlers or lift trucks
- working on top of combines or other high machinery
- moving ladders, irrigation pipes, or scaffolding
- tree work.
If you cannot avoid carrying out any of these activities closer than 10 m, consult your DNO for advice. If the line cannot be moved or made dead, you will need to assess the risks and agree a safe system of work.
- If part of a vehicle or load is in contact with an OHPL, the operator should remain in the cab and inform the DNO immediately (display the number in the cab and keep it on your mobile phone).
- If possible, try to drive clear. Electrocution is possible if anyone touches both the machine and the ground at the same time. If you need to get out jump well clear so that no simultaneous contact is made between you, the vehicle and the ground.
- Do not return to the vehicle until the owner of the line has confirmed that the line has been de-energised and made safe.
- WARNING: Contact with an OHPL may cause the power supply to 'trip out' temporarily and it may be reconnected and re-energised automatically, without warning.
- Stay clear and warn others not to approach
Look at the Energy Network Association's (ENA) website for more information.
If you suspect there are underground cables owned by the DNO in the vicinity of where you propose to excavate, ask the DNO for plans to confirm their location. If they are in close proximity you may need to ask someone from the DNO to come and accurately locate them for you using appropriate cable detection equipment.
If you are intending to excavate where your own cables are present, then someone who is experienced in underground cable detection techniques should help you locate them. Always use safe digging techniques where cables are present.
Your electrical system
Make sure that:
- there is a readily accessible and clearly identified switch near each item of fixed machinery to enable a person to cut off the power in an emergency;
- power cables to machines are suitably protected (armoured cable, covered in thick flexible rubber or neoprene, or installed in conduit) with a good earth connection;
- there are enough socket outlets for the number of machines – overloading sockets by using adaptors is a fire hazard;
- fuses and circuit breakers are correctly rated for the circuit they protect. Fuses must never be bypassed, over-wired or wrapped with foil;
- socket outlets outdoors, in damp or corrosive atmospheres, or where steam or water jets are used, are of an appropriate type and protected by a residual current device (RCD). Get competent advice – never use a household-type socket for these applications;
- main switches are readily accessible and clearly identified, and everyone knows how to use them in an emergency;
- wiring is installed in conduit or similar to avoid damage by rats and mice;
- damaged cables and other faults are repaired or replaced immediately.
- installations are checked periodically and repairs carried out by a competent electrician;
Electrical tools used outdoors or where there is a lot of earthed metalwork should be either
- operated at reduced voltage from a safety isolating transformer (eg 110 volts centre tapped to earth); or
- be connected through an RCD which will cut off the power quickly if there is an earth fault.
Consider whether you can avoid using electricity altogether, eg by using pneumatic tools in the workshop, but check the noise levels are not too high.
Make sure you and your workers:
- use electrical plugs and fittings that are robust and suitable for wet or dusty conditions;
- regularly inspect the wiring and condition of all portable tools – including hired or borrowed tools;
- take suspect or faulty tools out of use and make sure they are not used until repaired by a competent person;
- make someone responsible for regularly operating the ‘test’ button on RCDs to ensure they work correctly;
- unplug or isolate appliances before cleaning or adjusting;
- provide enough socket outlets to keep the use of extension leads to a minimum;
- on welding sets, only use insulated leads and undamaged electrode holders.
It is important to know what to do if someone receives an electric shock. Remember always to disconnect the power source first. If that is not possible, never touch the electrocuted person except with non-conducting items and never
use metal. Resuscitation needs training and practice so make sure that you and your workers receive elementary first aid training. You can also display a copy of an ‘electric shock poster’ which shows what to do.