Insulated and Covered conductor systems for low and medium voltage over head distribution lines
Overhead distribution systems can be categorized into two broad heads based on voltage rating and insulation system. Distribution system based on voltage rating is broadly either low voltage (upto 1.1 KV) or medium voltage (upto 36KV). Transmission & Sub-transmission of power is done at higher voltages. Voltages between 33KV and about 230kv , called high voltage are used for sub-transmission & transmission of power. Voltage level above 230kv upto about 800kv is called EHV or extra high voltage and voltage level above 800kv is called UHV or Ultra High Voltage.
We now also have HVDS systems where lines right upto consumers small single phase transformers are run at medium voltage. In this system LV mains are conspicuous by their absence. Categories based on insulation type are either bare or covered.