High Voltage Currents

House Current Power

From a house gets some of the 240VAC for HVAC (Heating Ventalation and Air Conditioning) only for the condenser units for cooling, and also 120VAC goes to the rest of the house, powering a TV, an Oven, a Microwave oven, etc.

A condensing unit has been turned on with 240VAC.

240VAC watt hour meter

Commercial and Industreal Power

These ones are using 277/480VAC power, by a Three Phase Transformer, on a pad mount or pole mounted. Inside of the electical room, there is a small transformer which converts it to 240/120VAC.

500kVA three phase pad mount transformer at a school.

Transformer room.

Substations

A substation is a power source for step down power for Distrubution Lines, from the Transmission lines.

Substation Transformer.

Transmission Lines

Transmission Lines start at Power Plants, then go to Substations to distribute power though lower voltage lines. In most cases to a lower Transmission Voltages or Sub-Transmission Voltages. And sometimes straight to Distribution Voltages. Transmission Line Voltages veries to how long of a distance the line is going for or how much energy is gong to used thought the line. Transmission Voltages most commonly used are 110kv, 115kv, 138kv, 220kv, 230kv, 345kv, 380kv, 400kv, 500kv, 765kv, and 1000kv.  More rare of Transmission Voltage would be 161kv used by very little power companies.

138kV Lines

Diagram of a Lattice Tower and Mono Poles

347kV Line and Tower

Sub-Transmission Lines

Sub-Transmission Lines are between Transmission and Distrubution.

Distribution Lines

Distribution lines are wooden or iron poles that have insulators, and components like for example: Transformer, or a Capacitor Bank.

Delta Distribution Pole Diagram

A distribution line with insulators. (10kV)