Installation of Low Voltage Overhead Lines
Definition, Classification, Applications and Consideration
What is overhead lines?
An overhead power line is a structure used in electric power transmission and distribution that transports electrical energy across vast distances.
It is made up of one or more conductors (often multiples of three) hung from towers or poles.
Overhead power lines are often the most cost-effective method of transmitting huge amounts of electricity since the surrounding air offers good cooling, insulation throughout long passages, and allows optical inspection.
Classification by operating voltage
Overhead power transmission lines are classified in the electrical power industry by the range of voltages:
Low voltage (LV)
Less than 1000 Volts, used for connection between a residential or small commercial customer and the utility.
Medium voltage (MV)
Between 1000 Volts (1 kV) and 69 kV, used for distribution in urban and rural areas.
High voltage (HV)
Subtransmission less than 100 kV, subtransmission or transmission at voltages such as 115 kV and 138 kV, used for sub-transmission and transmission of bulk quantities of electric power and connection to very large consumers.
Extra high voltage (EHV)
Transmission from 345 kV, up to about 800 kV, used for long distance, very high power transmission.
Ultra high voltage (UHV)
Higher than 800 kV. UHV lines are a “game changer”, making a global electricity grid potentially feasible. UHV enables the transmission of five times more power, over six times the distance.
Use of area under overhead power lines
Overhead lines and structures may shed ice, creating a hazard.
Radio reception can be impaired under a power line
Overhead distribution and transmission lines near airfields are often marked on maps
Construction of overhead power lines have significant environmental effects
Environmental studies for such projects may consider the effect of bush clearing
Aviation accidents
Some power lines are marked with obstruction markers, especially near air strips or over waterways that may support floatplane operations. The placement of power lines sometimes use up sites that would otherwise be used by hang gliders.