July 2012 (UK) – A jogger running on a footpath came into contact with an 11KV power cable. It states that 36% of all electrically-related workplace fatalities were caused by overhead power lines between 20. In the USA, the Electrical Safety Foundation International (ESFI) is a non-profit organization dedicated exclusively to promoting electrical safety at home and in the workplace. Eight people have been killed in the last two years. In the last five years, there have been more than 1,140 near misses involving electricity on farmland. In the period 2012 to 2016, over 3000 haulage and transport vehicles were reported to have come into contact with overhead power lines, resulting in 59 people receiving injuries. It also gives information as to the procedures to follow if a worker or vehicle does come into contact with a conductor. This includes planning and preparation, eliminating danger, controlling access and work. In the UK, the Health & Safety Executive (HSE) publish guidance notes for the construction, agriculture and tree care industries when working near overhead power lines. These events include hurricanes, tropical storms, tornadoes, snow and ice storms and flooding. In the USA, power outages due to weather are the most common type of disruptive events. Other associated problems include anglers getting fishing lines entangled, kites and metallic helium balloons coming into contact and trees growing too close or through distribution power lines. The UK’s CAA and distribution network operators recommend a 50m exclusion zone for drone operation near overhead lines. Incidents of combine harvesters, cranes, tipping trailers, Hiab loader cranes and mobile elevated work platforms contacting power lines have been widely reported. Rotted or poles damaged over time can also lead to the same result.Įntanglement of vehicles with overhead lines is a major problem, especially on farms. Conductors can fall to ground level, especially if tensioning or supporting equipment completely fails or if a vehicle collides with a tower or pole. In hot weather cable expansion and heavy electrical loading causes sagging, along with ice formation in cold weather. Conductors can sag to breach safe height limits due to fallen branches, broken insulators and failed fixtures. Overhead power lines and their supporting infrastructure may fail over time due to ageing, natural phenomena or accidental contact by vehicles and humans, resulting in power outages and potential wildfires in dry vegetation regions if cables remain live. Over 3,200 Utility companies generate, transmit and distribute electricity for sale to over 145 million customers. Transmission systems are generally administered by a Regional Transmission Organization (RTO) or an Independent System Operator (ISO) which operates the region’s electricity grid and administers the region’s wholesale electricity markets. The North American bulk electric system consists of more than 360,000 miles of transmission lines, including approximately 180,000 miles of high voltage lines. Underground cables are also more likely subject to ground movement. In the USA, overhead power lines are more common due to the life-cycle cost of those underground, being 2-4 times the cost of overhead. Low voltage distribution lines are below 1KV and likely destined for residential or small business consumers. Medium voltage sub-transmission lines are between 1KV and 69KV for distribution in urban and rural areas. High voltage transmission lines are considered to be from 69KV up to around 100KV for bulk transmission to large consumers. Steel tower structures, pylons or wooden poles suspend electricity-carrying conductors across a range of operating voltages.īusiness and residential consumers are normally supplied by high, medium and low voltage lines that are categorized depending on their destinations. Overhead power lines are used to transmit and distribute electrical power across long distances, forming a power or national grid.
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