Electritian - definition
An electrician is a tradesperson specializing in electrical wiring of buildings, stationary machines. and related equipment. Electricians may be employed in the installation of new electrical components or the maintenance and repair of existing electrical infrastructure. Electricians may also specialize in wiring ships, airplanes, and other mobile platforms, as well as data and cable.
Many jurisdictions have regulatory restrictions concerning electrical work for safety reasons due to the many hazards of working with electricity. Such requirements may be testing, registration or licensing. Licensing requirements vary between jurisdictions.
The risk when working with electricity
Why do many people use the services of electricity while performing even simple repairs or replacement of components of electrical installations? This question can be answered in a very simple way - a lot of people afraid of any contact with the flow, because it can be extremely dangerous not only for health, but also for human life. Commonly known cases in which the electrician while performing their work was seriously injured and even died as a result of contact with electricity. On the other hand, many electricians have daily contact with electrical installations retains fewer and fewer safety work and then can easily lead to tragedy.
Some basic knowledge
Electric power is the rate at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt, one joule per second.
Electric power is usually produced by electric generators, but can also be supplied by sources such as electric batteries. It is usually supplied to businesses and homes by the electric power industry through an electric power grid. Electric power is usually sold by the kilowatt hour (3.6 MJ) which is the product of power in kilowatts multiplied by running time in hours. Electric utilities measure power using an electricity meter, which keeps a running total of the electric energy delivered to a customer.
Electrical power provides a low entropy form of energy and can be converted into motion or other forms of energy with high efficiency.
Electric power, like mechanical power, is the rate of doing work, measured in watts, and represented by the letter P. The term wattage is used colloquially to mean "electric power in watts." The electric power in watts produced by an electric current I consisting of a charge of Q coulombs every t seconds passing through an electric potential (voltage) difference of V is
P = \textwork done per unit time = \frac VQt = VI \,
Q is electric charge in coulombs
t is time in seconds
I is electric current in amperes
V is electric potential or voltage in volts