Chap 5 Key Terms 1

Question 1

alternating current (AC)

Answer 1

Electric current that reverses its direction many times per second at regular intervals, typically used in power supplies

Question 2

aluminum conductor steel-reinforced (ACSR)

Answer 2

Energized cable constructed from aluminum wire stranded around a steel core. Light weight and relatively low cost aluminum is often used as a conductor. However, it has a tendency to stretch when it heats, as it does when subject to high electric loads and elevated ambient temperatures. To minimize stretching and add strength aluminum wire is stranded around a steel core in this cable construction

Question 3

ampere (amp, A)

Answer 3

measure of current. One amp is the charge carried by 6.25x10 (to the 18) electrons moving past a given point in one second

Question 4

back feed

Answer 4

Electric flow in an unintended direction through a process whereby de-energized lines become energized from an external source such as a home generator

Question 5

cascading outage

Answer 5

A series of power interruptions on a transmission system whereby one interruption increases vulnerabilities and causes additional interruptions, which in turn caused further interruptions, potentially resulting in widespread blackouts

Question 6

circuit

Answer 6

Electrical network consisting of a conductor or series of conductors through which electricity flows, including a return path to the source

Question 7

conductivity

Answer 7

Capacity of a material to transmit electricity

Question 8

impedance

Answer 8

The sum of resistance– inductive resistance and capacitive resistance

Question 9

inductance

Answer 9

Electrification of a wire by passing it through a moving electromagnetic field

Question 10

interconnection reliability operating limit (IROL)

Answer 10

The value (such as MW, Mvar, amperes, frequency or volts) derived from, or a subset of the System Operating Limits, which if exceeded, could expose a widespread area of the Bulk Electrical System to instability, uncontrolled separations or cascading outages.

Question 11

intermittent fault

Answer 11

Repeated momentary interruptions in the same place due to the same cause

Question 12

interruption

Answer 12

Disruption of electrical supply

Question 13

lateral

Answer 13

Secondary or subordinate branch or root

Question 14

lightning arrestor

Answer 14

Device installed to protect electric facilities from voltage surges caused by sudden electrostatic discharges during electrical storms (lightning)

Question 15

line sectionalizer

Answer 15

Protective device mounted on distribution poles or crossarms that isolate line sections or protective zones in order to limit the number of customers who lose service as the result of a fault. They cut off current when an upstream recloser operates, isolating a fault in the line beyond the sectionalizer

Question 16

service drop

Answer 16

In an electrical utility system, a distribution secondary line that carries electricity from a transformer to a home or business

Question 17

short circuit

Answer 17

Current that is bypassing a designated conducting path

Question 18

sine wave

Answer 18

Graph of the changing intensity and direction of alternating current

Question 19

stator

Answer 19

Stationary part of an electrical generator. Contains field windings

Question 20

step-down transformer

Answer 20

Device that reduces voltage (e.g., between primary distribution and secondary distribution).

Question 21

step-up transformer

Answer 21

Device that increases voltage (e.g., from distribution to transmission).

Question 22

substation

Answer 22

Electric facility equipped with transformers, switching equipment, and protection and control devices such as circuit breakers, automatic line reclosers, capacitors, or voltage regulators. Voltage is changed in substations.