Electrical Safety on Construction

A detailed account of this topic is given in the HSE publication Electrical Safety on Construction Sites (HSG 141) and only a summary will be given here. 

Electrical safety on construction sites, HSG141, 1995, HSE Books... 

From an historical perspective, the problem with electrical safety on construction sites largely began after World War II when portable electric tools, electrically powered plant and electric lighting came into general site use. Up until the 1960s, there was no purpose-designed electrical distribution system available, so the main contractor would usually ask the electrical subcontractor to provide a minimum installation at minimal cost. 

BS 4363 Distribution units for electricity supplies for construction and building sites, was issued in 1968, and was amended in 1992 for compatibility with BS EN 60439-4 1994. This standard specifies the equipment. In 1969 BS CP 1017 appeared. This was the code of practice which describes how the BS 4363 apparatus was to be installed and used. This code was subsequently amended and renumbered as BS 7375 1996. See also HSE guidance booklet HS(G)141 - Electric Safety on Construction Sites. 

Chapter 24 Engineering science (J.R. Ridley) 479 Chapter 25 Fire precautions (Dr P. Waterhouse) 500 Chapter 26 Machinery hazards (Professor R. T. Booth) 555 Chapter 27 Mechanical handling (K. G. Pearson) 577 Chapter 28 Electricity (E. G. Hooper) 603 Chapter 29 Statutory engineering inspections (E. S. Long) 622 Chapter 30 Safety on construction sites (A. Pinder) 650 Chapter 31 Safe use of chemicals (S. Bradley) 679... 

The Construction (Health, Safety and Welfare) Regulations 1996 were made on 14 June 1990 and came into force on 2 September 1996 to implement part of Directive 92157/EC and should be read in conjunction with the Construction (Design and Management) Regulations. There are no specific electrical requirements, but Regulation 17 states that plant and equipment has to be safe and maintained in a safe condition. This would include the electrical installation. Standards for electrical installations on construction sites are explained in Chapter 11. 

The Health and Safety Regulations make reference to workers having a duty of care for the health and safety of themselves and others in the workplace. The Electricity at Work Regulations identify one responsible person on-site as the duty holder . This recognizes the responsibility of an electrician to take on the control of electrical safety for the whole construction site. 

Weather factors at jobsites have significant impact on the health and safety of construction workers. Conditions such as extreme heat, extreme cold, high winds, electrical storms, and rain or snow all present unique problems for your employees. 

The safety philosophy is based on dividing the site installation into two distribution systems the 400/230 V system where there is a comparatively high shock risk because the voltage to earth is 230 V, and the comparatively safe 110 V system where the voltage to earth does not exceed 64 V. The 400/ 230 V system is intended to be installed and maintained only by authorised and competent persons, i.e. those who are electrically qualified. The construction workers role is confined to operating the distribution equipment, which is metalclad, weatherproof and earthed. The portable apparatus which they constantly handle is all connected to the llOV system (see Fig. 11.1). 

Lithium s 47% fraction of the 3.61 bilUon rechargeable battery market in 1999s had become 52% and 3 billion by itself in 2002. Sony Corp. had about 33% of this market, and Sanyo Electric Company 23% in 2000. Sony originally developed the lithium-ion batteries, but in 2000 began converting much of its manufacturing capacity to the more profitable lithium polymer type. Sanyo Electric also produced about 32% of the nickel-cadmium, and 46% of the nickel hydride batteries in 2000 (Lerner, 2001 Jarvis, 2000). Considerable research has been conducted on rechargeable lithium batteries for automobiles, but by 2002 there were still major safety and construction problems. 

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