Chap 5 Key Terms 2

Question 1

conductivity

Answer 1

Capacity of a material to transmit electricity

Question 2

current

Answer 2

The flow of electricity

Question 3

current surge

Answer 3

Inrush of electricity caused when electrical devices, such as motors or transformers, are first switched on, at which time they can draw several times their normal operating electrical load; often occurs when circuits are first reenergized following an outage

Question 4

delta construction

Answer 4

Electric distribution configuration with 3 phases, but no common neutral wire. There is no fixed difference between phase-to-phase and phase-to-ground voltages

Question 5

distribution lines

Answer 5

In an electric utility system, electric supply lines usually energized between 2.4 and 23kV (contrast with transmission lines)

Question 6

distribution network

Answer 6

In an electric utility system, the portion that delivers electricity to end-users. Includes distribution substations, primaries, distribution transformers, secondaries, and service lines.

Question 7

electrical potential (voltage)

Answer 7

Difference in electric energy between another energized conductor and an other energized conductor, the ground, or other object

Question 8

insulator

Answer 8

Material with poor conductivity–such as fiberglass, glass polymers, and porcelain– used to separate energized conductors from poles or other objects or structures that must not be energized

Question 9

lockout

Answer 9

Permanent operation that requires manual closure of automatic line reclosers

Question 10

megawatt

Answer 10

One million watts

Question 11

minimum vegetation clearance distance (MVCD)

Answer 11

Calculated minimum distance between conductors and vegetation to prevent spark-over, for various altitudes, and operating voltages, that is used in the design of transmission facilities

Question 12

momentary interruption

Answer 12

Transient fault in an electrical system, lasting from 33 to 133 milliseconds

Question 13

neutral wire

Answer 13

Common return path for an electric system

Question 14

North American Electric Reliability Corporation (NERC)

Answer 14

Not-for-profit international regulatory authority whose mission is to assure the reliability of the bulk power system in North America

Question 15

subtransmission lines

Answer 15

High-voltage lines generally energized between 69 and 161 kV. They can be as low as 35 kV. Subtransmission lines connect bulk transmission substations to industrial customers or distribution substations

Question 16

supervisory control and data acquisition (SCADA)

Answer 16

System that automatically collects data and enables remote control switching operations

Question 17

Switchyard

Answer 17

Electric facility that does not change voltage, but is used to route power through various circuits. May be strategically designed to compensate for portions of a system that are experiencing power failures, protecting circuits through disconnect switches, circuit breakers, relays, and communication systems (compare to substation).

Question 18

taps

Answer 18

Wire connection between energized conductor and other electrical equipment, such as transformers

Question 19

transformer

Answer 19

Electrical device that raises or lowers voltage through induction

Question 20

transient fault

Answer 20

fault that affects the dialectic properties of a system for an instant, and no longer exists after the power has been restored

Question 21

transmission interconnect

Answer 21

Region where transmission or extra-high transmission lines are connected. The interconnection allows utilities to transfer electricity both within their systems and among one another