Any electrical system has the potential to cause harm. Electricity can cause fatalities, injuries and fires. Shock to the body from electrocution can also cause secondary injuries, for example, from falling or moving suddenly. Electrical arching can generate intense heat and cause damage to the eyes. This ‘arching’ is as a result of the sudden flow of electricity between two electrically charged objects or an electrical short. A visible spark is often seen. Damage to equipment and unsafe working practices can cause arching. An electric arc has the highest current density and the current is only limited through the external circuit, not through the arc itself. Arching and overheating are real hazards with working with electricity. Most electrical accidents can occur when people work with live wires thinking they are dead or untrained operatives work with live circuits.
Sometimes a choice needs to be made whether it is best to work on charged or dead electrical equipment. ‘Dead’ means that the equipment is not electrically ‘live’ or ‘charged’. A ’charged’ item is said to be ‘live’ because it has electricity flowing through it. It may still be ‘live’ even though it may be disconnected from the rest of the system. Working on or near exposed conductors should rarely be permitted. This poses serious hazards to technicians and electricians. If possible, all work should be done on dead equipment. Working live should only occur if it’s unreasonable in all circumstances for the conductor to be dead and suitable precautions are taken by the worker, such as wearing personal protective equipment (PPE). If a worker is fault finding, for example, it may not be reasonable for them to work on dead equipment to clarify the problem. Disproportionate disruption and cost may occur if equipment is to be worked on dead, but a reasonable balance must be made to ensure health and safety for all.
If it is not feasible to work on equipment dead, a risk assessment must be carried out. Once the hazards have been identified from live work, it then needs to be assessed how likely harm can occur and the severity of injury. The risks need to be managed, including the competence of the workers. It must be considered that the risks working with live equipment can be very serious and minor inconveniences such as time and economic cost should not overrule this decision. Precautions with working with live equipment can include providing insulation, protective enclosures of screens and keeping unauthorized persons away. The area must be free from trip hazards with have adequate lighting to enable the works to be carried out. Tools must be insulated according to British Standards. Correct PPE must be used, for example, insulation gloves and flame resistant clothing.
Planning the work, whether on live or dead circuits, is critical. Planning should include the management, supervision, implementation and completion of the work. There should be safety rules and task specific risk assessments. Basically the plan should consider the work done, the hazards, the people doing the work, the precautions taken and the possibility that the work may change. According to the law, the Electricity at Work Regulations 1989 is applicable when working with all electrical systems, whether charged or dead. These regulations require precautions to be taken against the risk of death or personal injury. As is applicable to all work environments, The Health and Safety at Work etc Act 1974 also needs to be adhered to. The Electricity Safety, Quality and Continuity Regulations 2002 are concerned with the insulation and use of electric lines.