Work on electrical equipment, machinery or installations should be:
It is essential that equipment, machinery or installations are prepared for the work to be carried out. This includes the isolation and release of all sources of energy (electrical, mechanical, hydraulic, pneumatic, etc), and may also involve additional work such as decontamination or the construction of a safe working platform. Isolation of energy sources should be secure, meaning that energy cannot be inadvertently re-introduced into the equipment, machinery or installation.
All work should be thoroughly planned so that it can be done safely and so that the completed installation or equipment is safe. HSE booklet Electricity at work, safe working practices provides information on how to plan electrical work in a wide range of industries. HSE guidance Electrical safety on construction sites provides information on how to plan electrical installations on construction sites.
Particular care should be taken when repairing equipment that is safety
related such as equipment in a potentially explosive atmosphere,
or which guards against contact with moving machinery. You should make
sure that the repair will not prevent the correct operation of the equipment
or adversely affect its safety in any way.
People working on electrical equipment, machinery or installations must be competent to do so. The level of competence required to do a task is dependent upon the complexity of that task and the amount of knowledge required. Assessing the suitability of an individual to do a task requires evidence of:
People who cannot demonstrate competence should not be allowed to work unless they are supervised by someone who is.
The Memorandum of guidance on the Electricity at Work Regulations 1989 provides information on competence.
Equipment that is installed should be suitable for the task it will perform and the environment within which it will be expected to work. A wide range of electrical equipment and work is covered by recognised standards that offer guidance on good engineering practice. For example, BS 7671:2001 Requirements for electrical installations, IEE Wiring Regulations, Seventeenth edition offers guidance on the requirements for the construction and testing of electrical installations. There is a list of some of the more common electrical standards on this web site. Most British and European standards can be purchased from British Standards Online
A European Directive, the Low Voltage Directive (2006/95/EC), places duties on the design, manufacture and supply of electrical equipment within the voltage ranges 50 - 1000 volts ac or 75 - 1500 volts dc. This Directive is implemented in Great Britain by the Electrical Equipment (Safety) Regulations 1994. These require electrical equipment to be safe and to conform to certain essential safety requirements. Department for Business, Innovation and Skills (BIS) has responsibility for policy on these regulations. Enforcement is undertaken by HSE for equipment intended for use in the workplace, and Local Authority Trading Standards departments for equipment intended for use elsewhere.