Working near power lines and cables
Are you working within 10m of overhead power lines (OHPLs) or does your work have the potential to breach this distance?
What you need to know
Contact with overhead power lines (OHPLs) causes fatal or severe electric shock and burn injuries. This can also happen when a person or object is close enough to a line for a flashover to occur.
Striking underground cables often leads to burn injuries from the resulting explosion. It may also result in electric shock if contact is made with live conductors.
All overhead lines and other electrical apparatus can be extremely dangerous. If you need to work near them, get competent advice from the owner of the lines, usually the Network Operator (NO).
Working near live overhead electric lines and underground electric cables is responsible for many incidents every year. These incidents often result in the death of or serious injury to people, damage to equipment and disruption of electricity supplies. A number of these incidents are related to tree work near live electrical equipment.
What you need to do
When arboricultural (aerial and ground) works are proposed within 10m (measured at ground level horizontally from below the nearest wire) of overhead power lines a risk based approach needs to be adopted. In practice this means that you should seek specialist advice and guidance from the owner of the power line (Network Operator) before undertaking any work within this distance.
You must also consider:
- work that is more than 10m from an OHPL but has the potential to breach it. Breaches could be caused by falling trees, timber and debris, or the use of MEWPs and cranes that in the event of collapse could fall within 10m of the power lines
- the presence and the risks from underground electrical cables and other utilities.
When you need to work near OHPLs, you need to agree with the owner of the line, usually the network operator (NO) for the power lines to be disconnected.
Remember to consider the risks from, and to, all overhead and underground utilities not just electricity
The power line owner (Network Operator) should assist in establishing a safe system of work. This could include:
- arranging for the electricity to be switched off
- refining safety distances (depending on the nature of work, methods and contractor competency) or
- arranging for works to be undertaken by a specialised utility arboricultural contractor.
The first choice when managing the risks from electricity should be to undertake the works dead.
Any decision to undertake live works must be justified, documented and meet the criteria of the Electricity at Work Regulations Regulation 14
"No person shall be engaged in any work activity on or so near any live conductor (other than one suitably covered with insulating material so as to prevent danger) that danger may arise unless -
(a) it is unreasonable in all the circumstances for it to be dead; and
(b) it is reasonable in all the circumstances for him to be at work on or near it while it is live; and
(c) suitable precautions (including where necessary the provision of suitable protective equipment) are taken to prevent injury"
You can minimise the risk of injury associated with any task with a work plan based on:
- Risk assessment
- Using competent staff
- Providing suitable equipment
- Applying safe work procedures.
To ensure that any tree work which has to be carried out near to live electrical equipment is done safely, only work:
- As recommended by the Network Operator
- According to the appropriate working procedures set up by the Network Operator using appropriately qualified and competent people
Carefully plan:
- The worksite
- Access routes in the worksite
- Tree-felling/pruning operations
- Timber extraction
For advice telephone the local Network Operator.
NB - In the case of conflicting published guidance regarding safety distances and working techniques the advice of the Network Operator should be sought for clarification before proceeding.