Building Utilities (Electrical) Flashcards
The science dealing with the physical phenomena arising from the existence and interaction of electric charges.
Electicity
Potential difference or electromotive force expressed in volts; analogous to pressure in water flow.
Voltage
An amount of power, esp. the power required to operate an electrical device or appliance, expressed in watts.
Wattage
The complete path of an electric current, including the source of electric energy.
circuit
The basic SI unit of electric current, equivalent to a flow of one coulomb per second or to the steady current produced by one volt applied across a resistance of one ohm.
Ampere
The intrinsic property of matter giving rise to all electric phenomena, occurring in two forms arbitrarily given positive and negative algebraic signs and measured in coulombs. Opposite charges attract while like charges repel each other.
Electric charge
The SI unit of electric charge, equal to the quantity of electricity transferred across a conductor by a current of one ampere in one second.
Coulomb
The product of potential difference and current in a direct-current circuit. In an alternating current circuit, power is equal to the product of the effective voltage, the effective current, and the cosine of the phase angle between current and voltage.
Power
The SI unit of power, equal to one joule per second or to the power represented by a current of one ampere flowing across a potential difference of one volt.
Watt
The opposition of a conductor to the flow of current, causing some of the electric energy to be transformed into heat and usally measured in ohms.
Resistance
A machine that converts mechanical energy into electrical energy.
Generator
An electric device consisting of two or more windings wound on the same core, which employs the principle of mutual induction to convert variations of alternating current in a primary circuit into variations of voltage and current in a secondary circuit.
Transformer
The supplying of utilities, such as water, gas and electricity, required or demanded by the public.
Service
The decrease in voltage between two points on a power line, usually caused by resistance or leakage along the line.
Line Drop
Device measuring and recording the quantity of electric power consumed with respect to time.
Watt-hour meter
An auxiliary power station where electrical current is converted, as from DC to AC, or where voltage is stepped up or down.
Substation
Any of the conductors extending from the service equipment to various distribution points in a building.
Feeder
The Fractional part of a period or cycle through which time has advanced, measured from a specified reference point and often expressed as an angle.
Phase
A conducting connection between an electric circuit or device and the earth or other point of zero potential.
Ground
An abnormal, usually accidental condition of low resistance between two points in an electric circuit, resulting in a flow of excess current.
Short circuit
A device containing a strip or wire of fusible metal that melts under the heat produced by excess current, thereby interrupting the circuit.
Fuse
A switch that automatically interrupts an electric circuit to prevent excess current fro damaging apparatus in the circuit or fro causing a fire.
Circuit breaker
A board on which are mounted the switches, fuses, and circuit breakers for controlling and protecting a number of similar branch circuits, installed in a cabinet and accessible from the front only.
Panel
Any of several conducting rods installed at the top of a structure and grounded to divert lighting away from the structure.
Lighting rod
