A
Alternating Current - an electrical current, which reverses direction repeatedly due to a change in voltage, occuring at the same frequency. Often abbreviated AC or ac.
Alternator - an electric generator designed to produce alternating current.
Ampere - it measures the amount of electricity moving through a wire. Named after French physicist Andre M. Ampère
Ambient temperature - the surrounding temperature.
Ampere-hour - the flow of electricity equal to one ampere for one hour. Commonly used to rate the capacity of batteries.
Apparent power - the mathematical product of voltage and current on ac systems. Since voltage and current may not be in phase on ac systems, the apparent power thus calculated may not equal the real power, but may actually exceed it. |
B
Battery - a group of two or more cells connected together to provide electrical current. Sometimes also used to describe a single cell, which converts chemical energy to electrical current.
Battery cycle life - the number of discharge and recharge cycles that a battery can undergo before degrading below its capacity rating.
Battery self-discharge - the gradual loss of chemical energy in a battery that is not connected to any electrical load.
Bonding - an electrical conducting path formed by the permanent joining of metallic parts in order to assure electrical continuity and safely conduct any likely current.
Branch circuit - the conductors between the last over current protective device and the outlets or loads.
Top |
C
Capacitor - a device that stores electrical charge usually by conducting plates or foil separated by a thin insulating layer of dielectric material. Unit of measurement is Farad.
Cell - a single device which converts chemical energy into electrical current. Sometimes also referred to as a battery.
Charge rate - the rate at which a battery or cell is recharged.
Conductor - usually a metallic substance capable of transmitting electricity with little resistance. Best conductor is silver but the most common is copper.
Continuous load - a sustained electrical load current for three hours or more.
Coulomb - the practical unit of electric charge transmitted by a current of one ampere for one second.
Current - the flow of electricity commonly measured in amperes.
Top
|
D
Diode - an electronic device (semiconductor) that allows current to flow in only one direction.
Direct current - electrical current that normally flows in one direction only. Abbreviated dc. |
E
Electrolyte - a nonmetallic conductor of electricity usually consisting of a liquid or paste in which the flow of electricity is by ions.
Energy - the capacity for, or the ability to do, mechanical work. Electrical energy is measured in kilowatt-hours for billing purposes. |
F
Farad - a unit of capacitance. Named for the English physicist Michael Faraday 1867.
Fault - a short circuit.
Frequency - the number of complete alternations or cycles per second of an alternating current. Unit of measurement is Hertz.
Top
|
G
Generator - a rotating machine which converts mechanical energy into electrical energy.
Grid - Refers to the electrical utility distribution network. |
H
Hertz - Unit of frequency. One Hertz (HZ) s one complete cycle per second of an ac source. Named after the German physicist Heinrich R. Hertz 1894.
Horsepower - a unit of power equal to 746 watts.
|
I
Inductance - the characteristic of an electric circuit by which a voltage is induced in it by a variation of current..
Inverter - an electrical device, which is designed to convert direct current into alternating current.
Ion - a positively or negatively charged atom or molecule.
Top |
J
Joule - Named after James P. Joule, an English physicist 1889, Joules is the unit of work or energy equal to one watt for one second. One kilowatt hour equals 3,600,000 Joules. |
K
Kilovolt - unit of electrical potential equal to 1000 volts.
Kilovolt amperes - a unit of apparent power equal to 1000-volt amperes.
Kilowatt - unit of power equal to 1000 watts. Abbreviated kW or KW.
Kilowatt-hour - unit of energy or work equal to one kilowatt for one hour. |
L
Load - a device that consumes electrical power and is connected to a source of electricity. |
M
MCA - Minimum circuit amperes. This is the minimum current rating allowed for the wiring and circuit breaker or fuse protection for the equipment.
Top |
N
Neutral - a conductor of an electrical system, which usually operates with minimal voltage to ground. |
O
Ohm - a unit of electrical resistance. A circuit resistance of one ohm will pass a current of one ampere with a potential difference of one volt. Named after the German physicist George Simon Ohm 1854.
Open circuit voltage - the maximum voltage produced by a power source with no load connected.
Over current - any current beyond the continuous rated current of the conductor or equipment.
Overload - operation of electrical equipment above its normal full-load rating.
|
P
Power - the rate at which work is performed or that energy is transferred. Electric power is commonly measured in watts or kilowatts.
Top |
R
Resistance - the characteristic of materials to oppose the flow of electricity in an electric circuit. |
S
Short circuit - a low resistance connection unintentionally made between points of an electrical circuit which may result in current flow far above normal levels.
Single-phase - an ac electric system or load consisting of at least one pair of conductors energized by a single alternating voltage. |
T
Transformer - a device that converts one ac voltage and current to a different voltage and current. Constructed using two or more coils of wire around a common magnetic core. |
U
Uninterruptible power supply (UPS) - a device that provides a constant regulated voltage output in spite of interruptions of the normal power supply.
Top |
V
Volt - The electrical potential difference or pressure across a one-ohm resistance carrying a current of one ampere. Named after Italian physicist Count Alessandro Volta
Voltage drop - a voltage reduction due to impedances between the power source and the load. |
W
Watt - A unit of power equal to the rate of work represented by a current of one ampere under a pressure of one volt. Named after the Scottish engineer James Watt, 1819.
Top |
