pg 120-125Electrical Grid Distribution Systems Vocabulary

Vocabulary flashcards covering key terms, circuit types, structural characteristics, and components of electrical distribution grid systems.

Distribution Lines

Localized power delivery lines that are typically not longer than $50\,\text{miles}$, featuring shorter poles spaced an average of $300\,\text{feet}$ apart and utilizing aluminum conductors.

Transmission Lines

Long-distance power lines that may be several hundred miles long, used to carry power before it enters the localized distribution system.

Distribution System

An almost entirely alternating current system whose primary function is to receive electric power from the transmission system and safely distribute it to customers with acceptable quality, reliability, minimum power loss, and accurate energy measurement for billing.

Direct Current Distribution

A specific type of power distribution used in larger cities for specialized applications, such as operating elevators in high-rise buildings.

Substation

The starting point of the distribution system where individual circuits originate to deliver power across a service area.

Phase

An energized wire in an electrical distribution circuit.

Main Line

Also referred to as a feeder main, this is an always three-phase circuit with larger conductors that starts at the substation and serves as the main route to supply tap lines and customers.

Tap Line

A branch circuit that taps off from the main line, characterized by having smaller conductors than the main line.

WYE System

Also known as a star system, this is the most common circuit type, consisting of four wires: three phase conductors and one neutral conductor.

"V" Phase Construction

A circuit configuration on WYE systems where two phases and the neutral conductor are tapped off to serve light three-phase loads.

Three-Wire Circuit

A circuit originating from a WYE or DELTA source that lacks a neutral conductor, requiring single-phase transformers to be connected across two phases.