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Wikipedia about the job of linesman
A lineman (American English) or linesman (British English), also occasionally called a lineworker, powerline technician (PLT), or a powerline worker, is a tradesman who constructs and maintains electric power transmission and distribution facilities. The term is also used for those who install and maintain telephone, telegraph, cable TV and more recent fiber optic lines.
The term refers to those who work in generally outdoor installation and maintenance jobs. Those who install and maintain electrical wiring inside buildings are electricians.
Źródło: https://en.wikipedia.org/wiki/Lineman_%28technician%29
Why in many places it is still necessary to employ an electrician?
Although many people think that minor electrical repairs do not require the employment of a specialist such as a qualified electrician, the majority of jobs decides to offer a permanent job for an electrician. Why is this happening? Well, according to the law serious fault electrical installations may only be carried out by specialists. It is a profession of high risk and therefore must have the expertise to carry it out. In the absence of skills and knowledge of repair system can lead to severe injury or even a real tragedy.
Different levels of electricians - Wikipedia
Electricians are trained to one of three levels: Apprentice, Journeyman, and Master Electrician. Apprentices in the US and Canada are working to learn the electrical trade. They generally take several hundred hours of classroom instruction and are contracted to follow apprenticeship standards for a period of between three and six years, during which time they are paid as a percentage of the Journeyman's pay. Journeymen are electricians who have completed their Apprenticeship and who have been found by the local, State, or National licensing body to be competent in the electrical trade. Master Electricians have performed well in the trade for a period of time, often seven to ten years, and have passed an exam to demonstrate superior knowledge of the National Electrical Code, or NEC.
Źródło: https://en.wikipedia.org/wiki/Electrician