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100BaseT - A synonym for the Fast Ethernet network standard. The "100" refers to a maximum data-transfer rate of 100 megabits per second over twisted pair, copper wire.
10BaseT - A synonym for the Fast Ethernet network standard. The "10" refers to a maximum data-transfer rate of 10 megabits per second over twisted pair, copper wire.
10K - A grade level Box or Cover rating. See "Incidental Light Traffic".
1A - 1 Normally Open
1B - 1 Normally Closed
20A - A California ruling that has the investor owned utilities performing the under-grounding of electrical cables. The funds to perform the work are derived from rates and go into a sinking fund that is used at the discretion of the municipality the electric line is in.
20B - A California ruling that has the investor owned utilities performing the under-grounding of electric cables. The funds to perform this work are derived from a combination of rates and the developer of the land the line is on. This work is done at the discretion of the municipality the electric line is in.
20C - A California ruling that has the investor owned utilities performing the under-grounding of overhead electrical cables. The funds to perform this work are derived from the developer of the land the line is on.
20K - A grade level Box or Cover rating. See "Occasional Traffic".
2S1W - Two Speed, 1 Winding (motor).
2S2W - Two Speed, 2 Winding (motor).
600 Volt - Electrical systems, cables or service designed to be operated under 1000 Volts.
600V-UD - 600 Volt Underground Distribution Cable.
802.11 - 1. A set of IEEE standards for data transmission over wireless LANs. The specifications include 802.11, 802.11a, 802.11b and 802.11g. All of the specifications include Ethernet protocol. 2. A specification for a wireless LAN that operates in the 2.4GHz range and provides a data transmission rate of 1Mbps or 2Mbps using spread spectrum technology.
802.11a - A specification for a wireless LAN that operates in the 5GHz frequency range and provides a data transmission rate of 54Mbps using spread spectrum technology.
802.11b - A specification for a wireless LAN that operates in the 2.4GHz range and provides a data transmission rate of 11Mbps using spread spectrum technology. This specification was known as Wi-Fi but the term now applies to 802a and 802g as well.
802.11g - A specification for a wireless LAN that operates in the 2.4GHz frequency range and provides a data transmission rate, over short distances, of 54Mbps using orthogonal frequency division multiplexing (OFDM) technology.
802.1x - A security standard for wired and wireless LANs.

A
A - 1) Amperes; Amps. 2) Area. For cables Area is expressed in Circular Mils.
A-H - Ampere-Hour
AA - 1) The Aluminum Association. 2) Refers to All Aluminum as in All Aluminum Conductor.
AAC - All Aluminum Conductor.
AASHTO - American Association of Safety Highway Traffic Officials
AC - Alternating Current.
ACB - Air Circuit Breaker
Access Point - A wireless networked device usually connected to a wireless LAN used to access the wired LAN.
Accuracy - The degree of uncertainity for which a measured value agrees the ideal value.
ACSR - Aluminum Conductor Steel Reinforced.
ACSR-TW - ACSR conductor made using Trapezoidal Wire construction.
ACSS - Aluminum Conductor Steel Supported. This is a conductor that is generally used for overhead transmission construction. ACSS is often preferred over ACSR because of its superior sag characteristics.
ACSS-TW - ACSS conductor made using Trapezoidal Wire construction.
Active Material (Battery) - Material which reacts chemically to produce electrical energy when the cell discharges. The material returns to its original state during the charging process.
Active Power - A term used for power when it is necessary to distinguish among Apparent Power, Complex Power and its components, and Active and Reactive Power.
Admittance - The reciprocal of Impedance (1/Z).
ADSL - Asymmetric Digital Sunscriber Line. ADSL uses standard phone lines to provide high speed data communications. ADSL upstream speeds (from the user) normally top out at 128Kbps and downstream (to the user) at no more than 1.5Mbps. A separate phone line is not required for ADSL service.
AEIC - Association of Edison Illuminating Companies.
Aeolian Vibration - A natural forced vibration caused by wind flowing over a conductor. This occurs at alternate wind induced vortices and at wind speeds typically at 8 to 12 MPH. Contact Young & Company for additional information including the formula to calculate Aeolian Vibration.
Aerial Cable - An assembly of insulated conductors installed on a pole or similar overhead structures. It may be self supporting or attached to a messenger cable.
AFCI - Arc Fault Circuit Interrupter
AFD - Adjustable Frequency Drive
AFI - Arc Fault Interrupter
AIC - Arc Interrupting Current
Air Blast Breakers - A variety of high voltage circuit breakers that use a blast of compressed air to blow-out the arc when the contacts open. Normally, such breakers only were built for transmission class circuit breakers.
Al - The chemical symbol for aluminum.
Alarm - A signal for attracting attention to some abnormal event.
ALJ - Administrative Law Judge
Alley Arm - A side brace for a crossarm that is not loaded (balanced) evenly.
Alley Roadway (Lighting) - Narrow public ways within a block, generally used for vehicular access to the rear of abutting properties.
Alligator - A speciallized tool attached to a hot stick used to tie a wire or cable into an insulator.
Alloy - A metal formed by the combination of two or more metals.
Alternating Current - An electric current that reverses direction at regular intervals, having a magnitude that varies continuously in a sinusoidal manner.
Ambient Temperature - The temperature surrounding an object.
American Wire Gage (AWG) - A standard system used in the United States for designating the size of an electrical conductor based on a geometric progression between two conductor sizes.
AMF (Lighting) - Average Maintained Footcandles
Ampacity - The current in amperes that a conductor can carry continuously under given conditions of use without exceeding its temperature rating.
Ampere - The unit expressing the rate of flow of an electric current. One ampere is the current produced by a difference in potential of one volt across a resistance of one ohm; An electic current flowing at therate of one coulomb per second.
Ampere-Hour - The use of one Ampere for one hour.
Ampere-hour capacity (storage battery) - The number of ampere-hours that can be delivered under specified conditions of temperature, rate of discharge, and final voltage.
Ampere-hour meter - An electricity meter that measures and registers the integral, with respect to time, of the current of a circuit in which it is connected.
Anchor - A device that supports and holds in place conductors when they are terminated at a pole or structure. The anchor is buried and attached to the pole by way of guy wire to counteract the mechanical forces of these conductors.
Anneal - The process of controlled heating and cooling of a metal. In wire and cable products, copper and aluminum are annealed to increase flexibility while maintaining adequate strength.
Anode - 1) The positive electrode, that emits positive ions and attracts negative ions, within a voltaic cell or other such device. 2) The positive pole of a battery.
ANSI - American National Standards Institute. ANSI is located at 1430 Broadway, New York, NY 10018.
Antenna Gain - An antenna's transmission power, provided as a ratio of its output (send) signal strength to its input (recieve) signal strength, normally expressed in dBi. The higher the dBi, the stronger the antenna.
Apparent Power (volt-amps) - The product of the applied voltage and current in an ac circuit. Apparent power, or volt-amps, is not the true power of the circuit because the power factor is not considered in the calculation.
AR - Automatic Recloser.
Arc - A dischare of electricity through air or a gas.
Armor - An outer metal layer applied to a cable for mechaical protection. Armor is comprised of factory formed wire, designed to be applied to a range of conductor sizes. Preformed Line Products manufacturers Armor.
Armor Rod - An outer metal layer applied to a cable for mechaical protection. Armor Rods are comprised of factory formed wire, designed to be applied to a range of conductor sizes. Preformed Line Products manufacturers Armor Rods.
Arrester - Short for Surge Arrester, a device that limits surge voltage by diverting it.
Askeral - A generic term for a group of synthetic, fire-resistant, chlorinated aromatic hydorcarbons used as electrical insulated fluids.
ASTM - American Society for Testing and Materials. ASTM is located at 1916 Race Street, Philadelphia, PA 19103.
ATC - Available Transfer Capacity
ATP - Alternative Transient Program
Automatic line sectionalizer - A self-contained circuit-opening device that automatically opens the main electrical circuit after sensing and responding to a predetermined number of successive main current impulses.
Automatic Recloser - An automatic switch used to open then reclose following an over current event on a distribution voltage (medium voltage) line.
Autotransformer - A transformer in which at least two windings have a common section. They are use to either "buck" or "boost" the incoming line voltage.
Auxiliary Power - The power required for correct operation of an electrical or electronic device, supplied via an external auxiliary power source rather than the line being measured.
Average Maintained Footcandles (Lighting) - (ILL x CU x LLF)/(PS x RW)
AWG - American Wire Gauge.

B
Baker Board - A platform used to work above the ground on a wood pole.
Balanced Load - Refers to an equal loading of the phases in a polyhphase system (current and phase angle).
Balanced polyphase system - A polyphase system in which both the currents and voltages are symmetrical.
Ballast - A device that by means of inductance, capacitance, or resistance, singly or in combination, limits the lamp current of a fluorescent or high intensity discharge lamp. It provides the necessary circuit conditions (voltage, current and wave form) for starting and operating the lamp.
Bandwidth - The data carrying capacity of of a transmission path, measured in bits or bytes per second.
Bank - A group of electrical devices, usually transformers or capacitors, connected in a way to increase capacity.
Basic impulse level (BIL) - A reference impulse (voltage) insulation strength expressed in terms of the peak value of the withstand voltage of a standard impulse voltage wave. It is used to express the ability of electrical equipment such as transformers to withstand certain levels of voltage impulses like lightning strokes.
Basic Insulation Level - A design voltage level for electrical apparatus that refers to a short duration (1.2 x 50 microsecond) crest voltage and is used to measure the ability of an insulation system to withstand high surge voltage.
Battery - A combination of two or more chemical cells connected together electronically to produce electrical energy.
Battery Tray - A contained with a base and walls for holding several cells or batteries.
Bay-O-Net - A fusing device frequently used to protect transformers and downstream devices. A Bay-O-Net fuse fuse may include a Partial Range Current Limiting Fuse in series with n under oil fuse link.
Beacon - In wireless networking, a beacon is a packet sent by a connected device to inform other devices of its presence and readiness.
Beam Spread - With regard to outdoor lightg, the angle between the two directions in a plane in which the intensity is equal to a stated percentage of the maximum beam intensity. The percentage is typically 10% for floodlights and 50% for roadway luminaires.
Belt - Refers to a lineman's climbing belt.
Bikeway (Lighting) - Any road, street, path or way that is specifically designated as being open to bicycle travel, regardless of whether such facilities are designed for the exclusive use of bicycles.
BIL - 1) See Basic Insulation Level. 2) See Basic Impulse Level.
Blackout - The complete interrupting of load to an electric utility customer or group of customers to reduce overall load on the system.
Blowing - The act of installing fiberoptic cable into a duct using air pressure.
Bluetooth - A wireless computing and telecommunications specification that defines how mobile personal computing devices work with each other and with regular computers and phone systems within a close range.
Bonding - The permanent joining of metallic parts to form an electrically conductive path that will ensure electrical continuity and the capacity to conduct any current to be present in a safe manner.
Boomer - A lineman that moves from job to job.
Boost Charge - A charge applied to a battery which is already near a state of full charge, usually of short duration.
Breakdown Voltage - The voltage at which a dielectric material fails.
Breaker - see "Circuit breaker".
Brownout - Refers to a reduction of voltage on the system. This effectively dims the lights. Systems in the eastern parts of the U.S. where networks are integrated use brownouts as a means of conserving energy.
Buck - The act of lowering the voltage.
Bucket - A basket or platform that supports one or more linemen attached to a boom of a truck.
Bucket Truck - An aerial lift truck used to lift men high enough to work on overhead lines.
Building Wire - Conductors and cables used in commercial building construction.
Bulb - The outer enclosure of a light source; usually glass or quartz.
Bulb Envelope Lighting) - The outer enclosure of a light source; usually glass or quartz.
Bull Line - Heavy line used to pull wire or cable into a conduit or into an overhead configuration.
Bull Wheel - A reel device used to hold tension during the wire installation process.
Bunched Stranding - A term applied to a number of wires twisted together in one direction in one operation without regard to their geometric arrangement.
Bundle - Multiple cables used to form one phase of an overhead circuit.
BURD - Buried Urban Residential Distibution.
Burden - Load imposed by an electronic or electrical device on the measured input circuit, expressed in volt-amps.
Buried Urban Residential Distibution - Refers to the system of electric utility equipment installed below grade.
Bus - A conductor, which may be a solid bar or pipe, normally made of aluminum or copper, used to connect one or more circuits to a common interface. An example would be the bus used to connect a substation transformer to the outgoing circuits.
Bushing - An insulator having a conductor through it, used to connect equipment to a power source.
Bushing Well - See Universal Bushing Well.

C
C - Centigrade or Celsius
C-Rate - Battery discharge current in amperes; numerically equal to rated capacity of a cell in ampere-hours.
C2H4 - Ethylene.
C2H6 - Ethane.
Cable - A term generally applied to the larger sizes of bare or weatherproofed (covered) and insulated conductors. It is also applied to describe a number of insulated conductors twisted or grouped together.
Cable Cleaner - A chemical compound used to clean dirt, residual insulation & semi con and other foreign material from an insulated cable during the termination process.
Cable Pulling Lubricant - A chemical compound used to reduce pulling tension by lubricating a cable when pulled into a duct or conduit.
Cable Sheath - The outermost covering of a cable providing overall protection
Cable Tray - A rigid structural system used to support cables and raceways. Types of cable trays include ladder, ventilated trough, ventilated channel, and solid bottom
CAIDI - A distribution circuit reliability average interruption duration index. It represents the average time required to restore service to the average customer per sustained interruptions.
CAIFI - The customer average interruption frequency index. It is designed to show trends in customers interrupted and helps to show the number of customers affected out of the whole customer base.
Cal-ISO - See California Independent System Operator.
Calibration - Adjustment of a device so the output is within a specified range for particular values of the input.
California Independent System Operator (Cal-ISO) - The FERC-regulated control area operator of the California transmission grid. Its responsibilities include providing nondiscriminatory access to the grid, managing congestion, maintaining the reliability and security of the grid, and providing billing and settlement services. Cal-ISO is based in Folsom, CA, near Sacramento, with a backup control site in Alhambra, CA.
California Power Exchange (CalPX) - Now defunct, this independent California agency was responsible for conducting an auction for the generators seeking to sell energy and for loads that are not otherwise being served by bilateral contracts. The CalPX was responsible for scheduling generation in its day-ahead and hour-ahead markets, for determining hourly market-clearing prices, and for settlement and billing for suppliers and utility distribution companies (UDCs) using the PX's market. The PX was based in Alhambra, CA.
California Public Utilities Commission (CPUC) - Headquartered in San Francisco, the CPUC regulates telecommunications, electric, natural gas, water, railroad, rail transit and passenger transportation companies. The CPUC is chartered by the State of California to assure consumers have safe, reliable utility service at reasonable rates. It is also charged with protecting consumers from fraud and promoting the health of California's economy. The governor appoints five commissioners, who must be confirmed by the Senate, for six-year staggered terms. The governor appoints one of the five to serve as commission president.
Can - Slang for an overhead transformer.
Candela (cd) - The standard unit for luminous intensity. One candela is equal to one lumen per steradian.
Candlepower - Luminous intensity expressed in candelas.
Candlepower Distribution Curve - A curve, generally polar, representing the variation of luminous intensity of a lamp or luminaire in a plane through the light center.
Capacitance - 1) The ratio of an impressed charge on a conductor to the corresponding change in potential. 2)The ratio of the charge on either conductor of a capacitor to the potential difference between the conductors. 3) The property of being able to collect a charge of electricity.
Capacitor - An electrical device having Capacitance.
Capacitor bank - An assembly of capacitors and all necessary accessories, such as switching equipment, protective equipment, controls, etc., required for a complete operating installation.
Capacity (Battery) - The quantity of electricity delivered by a battery under specific conditions, usually expressed in ampere-hours.
Cat 5 Cable - See "Category 5 Cable"
Category 5 Cable - Also known as "Cat 5", this cable is used for fast ethernet and telephone communications. The cable is constructed of 4 twisted pair of copper wire.
Cathode - 1) The negative electrode, that emits electrons or gives off negative ions and toward which positive ions move or collect in a voltaic cell or other such device. 2) The negative pole of a battery.
CB - Circuit Breaker
CDMA - Code Division Multiple Access. CMDA is a technique used mainly with personal communications devices such as mobile phones that digitizes the conversation and tags it with a special frequency code. The data is then scattered across the frequency band. The receiving device is instructed to decipher only the data corresponding to a particular code to reconstruct the signal.
Cell (Battery) - An electrochemical device composed of positive and negative plates, separator, and electrolyte which is capable of storing electrical energy.
Cell Voltage (Battery) - See "Nominal Voltage (Battery)".
Cell-Reversal (Battery) - Reversing of polarity within a cell od a multi-cell battery due to over discharge.
CH2H2 - Acetylene
CH4 - Methane.
Charge (Battery) - The conversion of electrcal energy from an external source, into chemical energy within a cell or battery.
Charge Rate (Battery) - The rate at which current is applied to a secondary cell or battery to restore its capacity.
Charge-Retention (Battery) - The tendency of a charges cell or battery to resist self-discharge.
Cherry Picker - An aerial lift truck. Also see Bucket Truck.
Chlorinated Polyethylene - Chlorinated Polyethylene. CPE, a thermoplastic compound, is used to jacket certain types of power cable.
Choker - A Sling.
Circuit - A conductive path over which an electric charge may flow.
Circuit Breaker - A device that can be used to manually open or close a circuit, and to automatically open a circuit at a predetermined level of overcurrent without damage to itself.
Circuit Voltage - The greatest root-mean-square (effective) difference of potential between any two conductors of the circuit.
Circular-Mil (cmil) - The area of a circle with a diameter of one mil (1/1000 inch), used to describe the cross-sectional area of a conductor. One cmil equals approximately 0.0000008 square inches.
Clearing Time - The total time needed for a protective device such as a fuse or circuit breaker to clear a fault.
CLF - Refer to "Current Limiting Fuse".
Client - As part of a computer network, where a server is employed, this is the customer or non-server side. When you log onto a server, from another computer, the word "Client" refers to you, your computer or your software.
Climbers - Hooks for climbing poles that are attached to a lineman's boots.
CO - Carbon Monoxide.
Coax Cable - See "Coaxial Cable".
Coaxial Cable - Also known as "Coax", this cable is typically used to connect TV to its video source. Coaxial Cable consists of a small copper wire or tube, surronded by an insulating material and another conductor with a larger diameter, normally copper braid or a conductive tube. The cable is jacketed for mechanical and electrical protection.
Coefficient of Utilization (CU) - The percentage of light generated within a luninaire which ultimately strikes the work surface. It is usually expressed as a decimal percentage.
Coffin Hoist - A chain hoist of any type.
Coil Loss - Power loss in a transformer due to the flow of current. These losses are present only when the transformer is serving a load. Load losses vary by the square of the current magnitude. Load losses are composed of losses due to the current flow through the resistance of the conductors as well as eddy losses in the windings and stray losses due to current flow through other components.
Cold - Refers to non-energized equipment, lines or circuits.
Collector Roadway (Lighting) - The distributor and collector roadways servicing traffic between major and local roadways. These are roadways used mainly for traffic movements within residential, commercial and industrial areas.
Combination Unilay - A stranding comfiguration that uses two strand sizes to achieve a 3% reduction in the conductor diameter without conpression
Come-a-long - A wire grip for holding a conductor or strand under tension.
Commercial (Lighting) - A business area of a municipality where there are ordinarily many pedestrians during night hours. The definition applies to densely developed business area outside, as well as within, the central part of a municipality. The area contains land use attracting a relatively heavy volume of nighttime vehicular and/or pedestrian traffic on a frequent basis.
Compact Stranding - A stranding configuration with concentric strands in which each layer is passed through a compacting die to reduce the conductor diameter by approximately 10%
Competition Transition Charge (CTC) - A charge itemized on customer bills to recover costs associated with investor owned utility investments in generation-related assets and state-mandated contracts with nonutility generators that may now be uneconomic and unrecoverable in the restructured electric utility industry.
Compliance Voltage - The specified maximum voltage that a transducer (or other device) current output must be able to supply while maintaining a specified accuracy.
Compound - An insulating or jacketing material made by mixing two or more ingredients
Compressed - A stranding configuration with concentric strands in which either all layers or the outer layer only is passed through a die to reduce the conductor diameter by 3%
Compression Splice - A compression connector used to join two conductors. There are different designs used for overhead and underground conductors. For overhead conductors, there are different designs for limited and full tension applications.
Concentric Stranding - A stranding configuration in which individual wires are stranded concentrically with no reduction in overall diameter. Typically used for bare conductors
Conduct - The ability of two conductors separated by a dielectric to store electricity when a potential difference exists between the conductors.
Conductivity - The capability of a conductor to carry electricity, usually expressed as a percent of the conductivity of a same sized conductor of soft copper
Conductor - 1) A wire or combination of wires suitable for carrying an electrical current. Conductors may be insulated or bare. 2) Any material that allows electrons to flow through it.
Conductor Loss - See "Coil Loss".
Conductor Shield - A semiconducting material, normally cross-linked polyethyene, applied over the conductor to provide a smooth and compatible interface between the conductor and insulation. This smooth semiconducting shield is at the same potential as the conductor resulting in dielectric field lines that are not distorted.
Conduit - A channel for holding and protecting conductors and cables, made of metal or an insulating material, usually circular in cross section like a pipe. Also referred to as Duct.
Conduit Fill - Volumetric measurement of the duct space occupied by the cables inside, expressed as a percent.
Connector - A conductive coupling device used to connect conductors together.
Constant Current Charge - Charging technique where the output current of the charge source is held cunstant.
Constant Potential Charge - Charging technique where the output voltage of the charge source is held constant and the current is limited only by the resistance of the battery.
Continuity Test - A test performed on a conductor to determine if it is unbroken throughout its length
Continuous - See Continuous Rating.
Continuous Load - An electrical load in which the maximum current is expected to continue for three hours or more
Continuous Rating - The constant voltage or current that a device is capable of sustaining. This is a design parameter of the device.
Coordination - Relating to the protection of the power system, the process of coordinating the fuse, breakers and reclosers of a system so to allow the down stream devices to operate first.
Copolymer - Chains of unlike molecules that are chemically bonded together
Core Loss - Power loss in a transformer due to excitation of the magnetic circuit (core). No load losses are present at all times when the transformer has voltage applied. No load losses vary based on the applied voltage, and are essentially constant whether the transformer is supplying a load or not.
Corona - See Corona Discharge.
Corona Discharge - An electrical discharge at the surface of a conductor accompanied by the ionization of the surronding atmosphere. It is normally accompanied by light and audible noise.
Coulomb - A unit of electric charge in SI units (International System of Units). A Coulomb is the quantity of electric charge that passes any crossection of a conductor in one second when the current is maintained constant at one ampere.
Counter EMF - Voltage or cell or battery opposing the voltage of the charging source.
Cover - Top surface section of the handhole for closing the top access opening of the box section.
CPE - Chlorinated Polyethylene. CPE is a thermoplastic compound that is used to jacket certain types of power cable.
CPUC - See California Public Utilities Commission (CPUC).
Creepage Distance - The shortest distance between two conductors as measured along the device that separates them. Creepage Distance is normally a design parameter of insulators or insulating bushings.
Crest - See Crest Value.
Crest Value - The maximum value of a wave form. This is normally associated with electrical fault magnitude or transients.
Cross-Linked Polyethylene (XLPE) - A Common thermoset insulation material for building wire and cable Polyethylene made from petroleum and natural gas. It undergoes a crosslinking chemical reaction during a curing process that causes the compound molecules to bond, forming heavier molecules with desired physical and chemical properties.
CSA - Canadian Standards Association. CSA is located at 178 Rexdale Blvd, Toronto, Ontario, Canada M9W 1R3.
CSP - Completely Self-Protected transformer.
CST - Customer Subsurface Transformer.
CT - See "Current Transformer".
CTC - See Competition Transition Charge.
Cu - The chemical symbol for copper.
CU (Lighting) - Coefficient of Utilization
Current - 1) The movement of electrons in a conductor measured in Amperes. 2) Also see Ampere.
Current Limiting Fuse - A fuse designed to operate at the current zero crossing. Also see "Zero Crossing".
Current Transformer - A transformer used measure the amount of current flowing in a circuit. Its primary winding is rated in excess of the expected current of the circuit and the secondary will normally be rated at 5 amps being equal to the nominal full primary current.
Current Transformer Ratio - 1) The ratio of primary amps divided by secondary amps. 2) The current ratio provided by the windings of the CT. For example, a CT that is rated to carry 200 Amps in the primary and 5 Amps in the secondary, would have a CT ratio of 200 to 5 or 40:1.
Cut Off Voltage - Battery Voltage reached at the termination of a discharge. Also Known as the End Point Voltage (EPV).
Cutoff (Lighting) - Luminaire light distribution is classified as cutoff when the candlepower per 1000 lamp lumens does not numerically exceed 25 (2.5%) at an angle of 90 degrees above nadir (horizontal), and 100 (10%) at a vertical angle of 80 degrees above nadir. This applies to any lateral angle around the luminaire.
Cutoff Angle (Lighting) - With regard to an outdoor lighting luminaire, the angle between the vertical axis and the first line of sight at which the bare light source is not visible.
Cutoff, Full (Lighting) - A luminaira light distribution with zero candela at an angle of 90 degrees or above and not more than 10% of emitted light above 80 degrees.
Cutoff, Non (Lighting) - A luminaira light distribution where there is no Candela restriction at any amgle.
Cutoff, Semi (Lighting) - A luminaira light distribution with 5% candela at an angle of 90 degrees or above and not more than 20% of emitted light above 80 degrees.
Cutout - See "Fused Cutout".
Cycle - In Alternating current, the change of the poles from negative to positive and back.
Cycle (Battery) - A sequence of discharge followed by a charge, or a charge folowed by a discharge, of a battery under specific conditions.

D
DA Bolt - A Double Arming Bolt.
Data Encryption Standard - See "DES".
Day ahead market - The forward market for the supply of electrical power at least 24 hours before delivery.
dB - See "decibel".
dBi - Decibels compared to an isotropic antenna. The higher the dBi, the stronger the antenna.
dBm - Decibels compared to one milliwatt. The higher the dBm, the higher the devices transmit or receive power.
DC - 1) Direct current. 2) Current that flows in one direction only.
Dead Front - Generally refers to equipment that is connected without exposed conductor. Dead front equipment is normally connected with elbows. Thomas & Betts Elastimold division manufacturers elbows and other medium voltage connection devices.
decibel - A logarithmic mathematical ratio that indicates a devices electric or acoustic signal to that of another
Deep Discharge (Battery) - Withdrawal of 50% or more of the rated capacity of a cell or battery.
Delivery Traffic Indication Message - See "DTIM".
Delta - A three phase connection where each phase is connected in series with the next, separated by a phase rotation of 120 degrees.
Delta-Wye - Refers to a transformer that is conected Delta on the primary side and Wye on the secondary.
Depth of Discharge - The portion of the nominal capacity from a cell or battery taken out during each discharge cycle, expressed in percent. Shallow Depth of Discharge is consideres as 10% or less. Deep Discharge is considered 50% or more.
Derating - Calculations that reduce standard tabulated ratings based, generally based on ambient temperature or proximity to a heat source.
DES - Data Encryption Standard. DES is an encryption, method that uses an algorithm for private key encryption, in which the sender uses the same private key as the recipient uses to decode it.
Design Load - The actual, expected load or loads that a device or structure will support in service.
Design Test - Tests done to equipment to verify the design meets certain established charactistics or standards.
DHCP - Domain Host Control Protocol. DHCP is a protocol used for dynamically assigning IP addresses to networked computers.
Dielectric - 1) Any electrical insulating medium between two conductors. 2) The medium used to provide electrical isolation or separation.
Dielectric Constant - A number that describes the dielectric strength of a material relative to a vacuum, which has a dielectric constant of one.
Dielectric Grease - A silicone based chemical compound used to seal and lubricate connections between medium voltage connectors such as cable termination elbows.
Dielectric Strength - The maximum voltage an insulation system can withstand before breakdown, expressed in volts per mil of insulation thickness.
Dielectric Test - A test that is used to verify an insulation system. A voltage is applied of a specific magnatude for a specific period of time.
Dielectric Withstand - The ability of insulating materials and spacings to withstand specified overvoltages for a specified time (one minute unless otherwise stated) without flashover or puncture.
Dielectric Withstand Voltage Test - The test to determine Dielectric Withstand.
Digital Subscriber Line - See "DSL".
Dip Tolerance (Lighting) - With regard to outdoor lighting, the percentage of instantaneous voltage variation from normal that is required to extinguish a light source.
Dipole Antenna - A type of antenna commonly used in wireless networking devices. It has a signal range of 360 degrees horizontally and 75 degrees vertically.
Direct Current - A unidirectional current. Also see "DC".
Direct Sequence Spread Spectrum - See "DSSS".
Discharge (Battery) - The conversion of the chemical energy of a cell or battery into electrical energy and withdrawal of the electrical energy into a load.
Discharge Current - The surge current that is disapated through a surge arrester.
Discharge Rate (Battery) - The rate of current flow from a cell or battery.
Disconnect Switch - A simple switch that is used to disconnect an eletrical circuit. It may or may not have the ability to stop the flow of current in the circuit.
Distribution Automation - A system consisting of line equipment, communications infrastructure, and information technology that is used to gather intelligence about a distribution system. It provides analysis and control in order to optomize operating efficency and reliability. The system can include distribution, small substation, and transmission line feeder reclosers, regulators and sectionalizers, which can be remotely monitored and controlled.
Distribution System - A term used to describe that part of an electric power system that distributes the electricity to consumers from a bulk power location such as a substation. It includes all lines and equipment beyound the substation fence.
Distribution Transformer - A transformer that reduces voltage from the supply lines to a lower voltage needed for direct connection to operate consumer devices.
DMZ - Demilitarized Zone. Networking has corrupted the term and used it to refer to an unprotected subnet connected to a local network, but outside the protection of a firewall.
DNS - Domain Name System. The DNS is an international network of Internet domain name servers, names, and addresses that enables locating computers on the internet.
Dolly - See "Stringing Block".
Domain Host Control Protocol - See "DHCP".
Domain Name System - See "DNS".
Door - The fuse tube of a fused cutout.
Double Arming Bolt - A special long bolt used to assemble two crossarms, one on each side of the pole.
Drawing - The process of reducing a cylindrical rod or wire to a desired diameter by pulling the wire through dies.
Dry Charge (Battery) - The process by which the electrodes are formed and assembled in a charged state. The cell or battery is activated when electrolyte is added.
Dry-Type Tranformers - Transformers that use only dry-type materials for insulation. These have no oils or cooling fluids and rely on the circulation of air about the coils to provide necessary cooling. Such units are usually limited in size to a few hundred kVA because of problems of cooling the larger units.
DSL - Digital Subscriber Line. A method to Lines carry data at high speeds over standard telephone lines.
DSSS - Direct Sequence Spread Spectrum. Used in radion transmission, DSSS alters, or modulates, the signal by spreading it over a wider frequency, generating what seems like signal noise to anything except the device that is designed to reassemble the signal into its original form.
DTIM - Delivery Traffic Indication Message. A DTIM is a signal sent as part of a beacon by an access point to a client device in sleep mode, alerting it that a packet of data awaits delivery.
Dual Voltage Switch - A switch used to select primary windings of a transformer.
Dual Voltage Transformer - A transformer that has switched windings allowing its use on two different primary voltages.
Duct - A channel for holding and protecting conductors and cables, made of metal or an insulating material, usually circular in cross section like a pipe. Also referred to as Conduit.
Duct Bank - Two or more ducts or conduits used as part of a system.
Dynamic DNS - This is a system by which Internet Service Providers temporarily assign IP addresses. THis allows the reassignment of the address when no longer in use.

E
Eddy Current - The current that is generated in a transformer core due to the induced voltage in each lamination. It is proportional to the square of the lamination thickness and to the square of the frequency.
EEI - Edison Electric Institute.
EERA - Electrical Equipment Representatives Association. EERA is an association of electrical manufacturers representatives. Additional information on EERA can be found at www.eera.org. Young & Company is a member of EERA.
Effective Internal Resistance (Battery) - The apparent opposition to current within a battery that manafests itself as a drop in battery voltage proportional to discharge current. Its value is dependent on battery design, state-of-charge, temperature and age.
Effective Power (watts) - With ac measurements, effective power (measured in watts) equals the product of voltage, current, and power factor (the cosine of the phase angle between the current and the voltage). Watts=EI cosine(Theta).
Effectively Grounded - Intentionally connected conductors or electric equipment to earth, where the connection and conductors are of sufficently low impedance to allow the conducting of an intended current.
Efficiency (Lighting) - A ratio of light emitted from a luminaire to the light produced by the bare lamp.
EHV - see "Extra High Voltage".
Elbow - A device used to connect a medium voltage cable to an electrical component such as a switch or transformer. Its name is derrived from the fact that its shape is an "L". Elbows are manufactured by the Elastimold division of Thomas & Betts.
Electricity - The flow of electrons through a conducting medium.
Electrolyte (Battery) - In a lead-acid battery, the electrolyte is sulfuric acis diluted with water. It is a conductor and also a supplier of hydrogen and sulfate ions for the reaction.
Electromotive Force - Potential causing electricity to flow in a closed circuit.
Elongation - The amount (% length) that a conductor or other material can stretch before breaking when a pulling force is applied.
EMS - See Energy Management System
EMTDC™ - Electro-Magnetic Transients for DC. Incorporates both EMTP and ATP, and integrates DC systems and components.
EMTP - Electromagnetic Transients Program
End Point Voltage - Battery Voltage reached at the termination of a discharge. Also Known as the Cut Off Voltage.
End-of-Discharge Voltage - The voltage of a battery at the termination of a discharge but before the discharge is stopped.
End-Point Voltage - The Cell or Battery voltage at which point the rated discharge capacity has been delivered at a specific Rate-of-Discharge. It is also used to specify the cell or battery voltage below which the connected equipment will not operate or below which operation is not recommended.
Energy - That which does work or is capable of doing work. Electricity is energy that is measured in kilowatt hours.
Energy Management System - A system in which a dispatcher can monitor and control the flow of electric power by opening and closing switches to route electricity or to isolate a part of the system for maintenance. It is also used to control the amount of generation needed to serve a load.
Entrainment (Battery) - The process whereby gasses generated in the cell carry electrolyte through the vent cap.
EPDM - Ethylene Propylene Diene Modified. This is a synthetic rubber compound used as insulation in making electrical components.
EPR - Ethylene Propylene Rubber, a synthetic rubber compound that is used as cable insulation.
EPRI - Electric Power Research Institute. EPRI is located at P.O. Box 10412, Palo Alto, CA 94303.
Eutectic - An alloy used to form the melting point of a fuse. It is frequently silver or tin based.
Exciting Current - The magnatizing current of a device such as a transformer. Also known a field current.
Expressway Roadway (Lighting) - A divided major roadway for through-traffic with partial control of access and generally with interchanges at major crossroads. Expressways for non-commercial traffic within parks and park-like area are generally known as parkways.
Extension, Box - An add-on section that fits to the bottom or to the top of a gread level box, extending its height.
Extra High Voltage - An electrical system or cable designed to operate at 345kv (nominal) or higher.
Extrusion - The application of a semi-solid rubber or plastic material such as PVC onto a conductor

F
F - Fahrenheit
Farad - The capacitance value of a capacitor of which there appears a potential difference of one volt when it is charged by a quantity of electricity equal to one coulomb.
Fault Current - The current that flows as a result of a short-circuit condition.
Fault Indicator - A device installed on a conductor to determine if current exceeded the indicator's current rating. Fault indicators sense using use the magnetic field induced by load current.
Federal Energy Reglatory Commission (FERC) - FERC is an independent regulatory agency within the U.S. Department of Energy that approves rates for wholesale electricity transactions and transmission of electricity in interstate commerce for utilities, power marketers, power pools, power exchanges and independent system operators. FERC also regulates the transmission and sale for resale of natural gas in interstate commerce; regulates the transmission of oil by pipeline in interstate commerce; licenses and inspects private, municipal and state hydroelectric projects; and oversees related environmental matters. The FERC board of governors is composed of five commissioners. The chairman, designated by the President, serves as the commission's administrative head. FERC is based in Washington, D.C.
Feeder - A three phase distribution line circuit used as a source to other three phase and single phase circuits.
FERC - Federal Energy Regulatory Commission.
Ferroresonance - In transformers, an over-voltage condition that can occur when the core is excited through capacitance in series with the inductor. This is especially prevalent in transformers that have very low core losses. It can generally be prevented by having a load connected to the transformer secondary. Contact Young & Company or Howard Industries for additional information.
Field Current - The magnatizing current of a device such as a transformer. Also known a exciting current.
Fill - In conduit or cable tray installations, the portion of the total cross-sectional area of the tray or conduit that can be occupied by conductors or cables
Filler - A material used in multiconductorcoble to occypy large interstices formed by the cable assembly. Also, a material added to an insulation compound to add volume and increase impact resistance
Fixed Capacitor Bank - A capacitor bank installed with no automatic switching device. The bank is manually switched on and off. Also see "Capacitor Bank".
Fixture - With regard to lighting, a reference to Luminaire.
Flame Resistance - The ability of an insulation or jacketing material to resist the support and comveyance of fire
Flashover - An unintended electrical discharge to ground or another phase. Flashovers can occur between two conductors, across insulators to ground or equipment bushings to ground.
Float Charge - A method of maintaining a cell or battery in a charged condition by continuous, long-term, constant voltage charging at a level sufficient to balance self-discharge.
Float Charge (Battery)MTI - A continuous low rate charge that compensates for the self discharge rate of a battery. Also known as Trickle Charge.
Flooded Cell - A cell design that incorporates an excess amount of electrolyte.
Flower Pot - Slang for "Universal Bushing Well".
Fluorencent Lamp - A low pressure Mercury, electric discharge lamp in which a fluorescing coating (Phosphor) transforms some of the ultraviolet energy generated by the discharge into light.
FOB - Free on Board. The point at which liability transfers from buyer to seller.
Footcandle (fc) - Standard unit of measure for illumination on a surface. The Average footcandle level on a square surface is equal to the lumens striking the surface, divided by the area of the surface.
Frequency - In ac systems, the rate at which the current changes direction, expressed in hertz (cycles per second); A measure of the number of complete cycles of a wave-form per unit of time.
FRP - Fiberglass Reinforced Plastic.
Full Scale - The specified maximum magnitude of the input quantity being measured that can be applied to a transducer without causing a change in performance beyond specified tolerance
Full Scale Output - The specified maximum output value for which the stated accuracy condition applies
Fuse - A device installed in the conductive path with a predetermined melting point coordinated to load current. Fuses are used to protect equipment from over current conditions and damage.
Fuse Link - 1. A replaceable fuse element used in a Fused Cutout. 2. A replacable part or assembly comprised entirely or principly of thr conducting element, requires to be replaced after each curcuit interruption to restore the fuse to operating conditions.
Fuse Melt Time - The time needed for a fuse element to melt, thereby initiating operation of the fuse. Also known as Melt Time.
Fused Cutout - A device, normally installed overhead, that is used to fuse a line or electrical apparatus.

G
Gassing (Battery) - The evolution of gas from one or more of the electrodes in a cell. Gassing commonly results from local action (self discharge) or from the electrolylis of water in the electrolyte during charging.
Gel - A chemical compound used to seal and mechanically cushion fiberoptic filament in a cable. The cleaners used to remove are made by American Polywater.
Gel Cleaner - A chemical based cleaned used to remove the gel in a fiberoptic cable. Gel cleaner is made by American Polywater Corp.
GF - Ground Fault
Gin - A device used for temporary lifting.
Glare - A sensation of uncomfortable brightness, usually coming from a luminaire at angles between horizontal and 45 degreesbelow horizontal.
Gnd - Ground
Grease - 1) Slang for Cable Pulling Lubricant, a chemical compound used to reduce pulling tension by lubricating a cable when pulled into a duct or conduit. 2) Slang for Dielectric Grease, a silicone based chemical compound used to seal and lubricate connections between medium voltage connectors such as cable termination elbows.
Grip All Stick - See Shotgun Stick.
Ground - 1. An electrical term meaning to connect to the earth. 2. A conducting connection, whether intentional or accidental by which an electric circuit, or equipment, is connected to the earth or some conducting body that serves in place of the earth.
Grunt - A lineman's helper.
Gut - Slang for "Line Hose".
Guy Strain Insulator - An insulator, normally porcelain, used to electrically isolate one part of a down guy from another. Guy Strain Insulators are made by Porcelain Products.

H
H - Henry.
H-20 - Also referred to as "HS20-44" or "H20-44" Bridge Loading. H20 Loading refers to a maximum front wheel loading of 8000 lbs and a maximum rear wheel load of 16,000 lbs with an impact factor of 30% added (16000 x 1.30) for a total maximum wheel loading of 20,800 lbs.
H2 - Hydrogen.
H20-44 - See "H20"
Hard Drawn - Wire that has been drawn to its specific size and not annealed.
Hard Line - A Steel Pulling line. Also see Bull Line.
Helical - Wrapped in a spiral fashion. Refers to the way the strands of a conductor are laid.
Henry - The meter-kilogram-second unit of inductance, equal to the inductance of a circuit in which an electromotive force of one volt is produced by a current in the circuit which varies at the rate of one ampere per second.
Hertz - 1) A unit of frequency equal to one cycle per second. 2) In alternating curent, the changing of the negative and positive poles.
HID - High Intensity Discharge
High Intensity Discharge (HID) Lamp - An electric discharge lamp in which the light producing arc is stabilized by wall temperature and the arc tube has a bulb wall loading in excess of 3 watts per square centimeter. Examples of HID lamps include High Pressure Sodium, Metal Halide and Mercury Vapor.
High Pot - A test done to confirm the reliability of an insulation system where a high voltage is applied.
High Pressure Sodium (HPS) Lamp - A High Intensity Discharge light source in which the arc tube's primary internal element is Sodium Vapor. HPS is commonly used for roadway and area lighting.
High Voltage - An electrical system or cable designed to operate between 46kv and 230kv.
High Voltage System - An electric power system having a maximum roo-mean-square ac voltage above 72.5 kilovolts (kv).
HMI - Man Machine Interface
Hooks - See "Climbers".
Hookstick - A hotstick that is used to operating switches and cutouts.
Horsepower - A unit of work. When used to show power usage, one horsepower is equivalent to 746 watts
Hose - Slang for "Line Hose".
Hot - Refers to an energized conductor or apparatus.
Hot Arm - A device that is used to temporarily extend a conductor beyond the crossarm it was on.
Hotstick - An insulated stick, ususlly made of fiberglass, that is used to work energized overhead conductors and operate electrical equipment that is overhead, underground and pad mounted.
HPS - High Pressure Sodium
HS20-44 - See "H-20"
HV - High Voltage.
Hydrometer - A float type instrument used to determine the state-of-charge of a battery by measuring the specific gravity of the battery electrolyte (i.e., the amount of sulfuric acid in the electrolyte).

I
ICEA - Insulated Cable Engineers Association. ICEA is located at P.O. Box P, Southe Yarmouth, MA 02664.
IEEE - Institute of Electrical and Electronics Engineers. Pronouncwd "eye-triple-E", this non-profit U.S. engineeering organization develops, promotes, and reviews standards within the electronics, computer and electric power industries.
IESNA - Illuminating Engineering Society of North America. Founded in 1906, IESNA is the recognized technical authority on illumination.
ILL (Lighting) - Initial Lamp Lumens
Illuminance - The density of the luminous flux incident on a surface. It is the quotient of the luminous flux multiplied by the area of the surface when the later is uniformly illuminated.
Impedance - 1) The total opposing force to the flow of current in an ac circuit. 2) The total resistance to flow of an alternating current, generally expressed in ohms. It is a combination of resistance and reactance .
Incandescent Lamp - A lamp in which light is produced by a filament heated to incandescence by an electric current.
Incidental Light Traffic - Refers to a grade level Reinforced Polymer Concrete or Fiberglass Reinforced Plastic box or Cover load rating of 10,400lbs. This rating is derived from incidental single vehicle tire contact estimated at a maximum of 8000lbs with an impact factor of 30% added (8000 x 1.30). In the US, this rating is also referred to as, "Light Traffic", 10K or "Parkway". Application is limited generally behind a curb or guardrail, in sidewalks, or in other locations where vehicle traffic is not intended.
Independent System Operator - See California Independent System Operator (Cal-ISO).
Induced Current - Current in a conductor resulting from the application of a time varying electromagnetic field.
Induced Voltage - A voltage produced around a closed path or circuit by a change of magnetic flux linking that path.
Inductance - 1) The property of a circuit in which a change in current induces an electro motive force. 2) Magnetic component of impedance.
Initial Lamp Lumens (Lighting) - (AMF x PS x RW)/(CU x LLF)
Instrument Transformer - A transformer that is only designed to reduce current or voltage from a primary value that is too pass directly through a meter or instrument, to a proportional low level that can safely be applied.
Insulation - 1) A non-conductive material used on a conductor to separate conducting materials in a circuit. 2) The non-conductive material used in the manufacture of insulated cables.
Southwire Company manufacturers insulated cables. Speed Systems manufacturers tools to strip insulation from cable.
Insulator - A device that is used to electrically isolate a conductor or electrical device from ground or a different electrical potential. Electrical insulators are manufacturered by Porcelain Products Company and W.H. Salisbury & Company.
Intensity (Lighting) - The brightness of light in a given direction. Luminous intensity may be expressed in Candelas (cd) or in Lumins.
Intermediate (Lighting) - Those areas of a municipality often characterized by moderately heavy nighttime pedestrian activity such as in blocks having libraries, community recreation centers, large apartment buildings, industrial buildings or neighborhood retail stores.
Internal Impedance (Battery) - The opposition to the flow of alternating current at a particular frequency in a cell or battery at a specific state-of-charge and temperature.
Internal Resistance (Battery) - The opposition or resistance to the flow of Direct Electric Current within a cell or battery; The sum of the ionic and electronic resistance of the cell components. Its value vay vary with the current, state-of-charge, temperature, and age. With an extreemly heavy load, such as an engine starter, the cell voltage may drop to approximately 1.6. This voltage drop is due to the internal resistance of the cell. A cell that is partly discharged has a higher resistance than a fully charged cell, hence it will have a greater voltage drop under the same load. This internal resistance is due to the accumulation of lead sulfate on the plates. The lead sulfate reduces the amount of active material exposed to the electrolyte, hence it deters the chemical action and interfers with the current flow.
International System of Units (SI) - A universal system of units in which the following six units of measure are considered basic: meter, kilogram, second, ampere, Kelvin degree and acndela.
Interrupting Medium - The "fluid" used to interrupt the flow of electric current in a switch or circuit breaker. In high power equipment, this may be oil, insulating gas or even no material, as is the case of vaccum interruption which works because in a vaccum there is no material that can be ionized to perpetuate the flow of electric current when the contact par and an arc tries to form. Air also can be used as an interrupting medium where the design of the interrupter is such that a stream of air blows-out and cools the arc path.
Interrupting Rating - The rating of a device to interrupt the flow of power or current, generally applied to a circuit breaker or a switch.
Interruption - The loss of electric service to one or more customers or other facilities. It is the result of one or more component outages.
Interruption Duration - The period from the initiation of an interruption to a customer or other facility to the time the service is restored.
Interruption, Momentary - An interruption of a duration limited to the period required to restore service by automatic or supervisory controlled switching operations or by manual switching at locations where operators are immediately available. Such switching operations must be completed within five (5) minutes, including all reclosing operations.
Interruption, Sustained - Any interruption not clasified as momentary. Any interruption longer that five (5) minutes.
Interstices - The space between two or more objects, such as the individual strands in a stranded conductor or conductors in a cable
Intranet - A restricted access network that works like the internet but is not. Usually owned and managed by a corporation, an Intranet enables a company to share its resources with its employees without confidential information being made available to everyone with internet access.
Invester Owned Utility (IOU) - A utility company whose assets are owned by investors and whose stock is publicly traded.
Ion - Part of an molecule or group of atoms, positively or negatively charged, that transports electricity.
IOU - See Invester Owned Utility
IP Address - Internet Protocol address. This address is a 32 bit, unique string of numbers that identifies a computer, a printer, or another device on the internet. The IP address consists of a quartet of numbers separated by periods.
ISM Band - The 2.4GHz frequency spectrum. ISM is actually synonymous with 2.4GHz, however it stands for Industrial, Scientific and Medical.
ISO - Independent System Operator
Isolation - To be electrically separate. A measure of the strength of the dielectric providing the electrical division or separation.
Isotropic Antenna - A theoretical, ideal antenna having a signal range of 360 degrees. It is used as a baseline for measuring a real antenna's strength signal, in dBi, where i represents Isotropic Antenna.

J
Jacket - A covering over insulated conductors for the purpose of electrical, chemical, and physical protection.
Jamming - When the combined diameters of three cables roughly equal the interior diameter of the conduit, the cables can line up linearly as they are pulled around the bend. The cables then wedge against the conduit wall as they are forced towards the inside of the bend. The wedged (or jammed) cables are "stuck." To pull jammed cables with enough force to get them through a bend usually ruins the cable by ripping off the jacket or crushing the insulation.
JIT - Just in Time
Johnny Ball - Slang for "Guy Strain Insulator".
Joule - 1) Work done by the force of one neuton when its point of applicaton moves through the distance of one meter in the direction of the force. 2) One watt-second.
Jumper - An electrical connection between two points.

K
kcmil - One thousand circular-mils (see Circular-Mil)
Kilo - A prefix indicating one (1) thousand.
kVA - Apparent Power expressed in Thousand Volt-Amps.
kW - Actual Power expressed in Kilo-Watts (KW).
kWh - Kilo Watt Hour, the use of one thousand watts for one hour.
KYZ - A designator for the Form-C pulse initiator output from a transducer.

L
L - A symbol used to express inductance. The unit measure is Henry.
Lag - The condition where the current is delayed in time with respect to the voltage in an ac circuit (for example, an inductive load).
Lamp - A complete light source unit, usually consisting of a light generating element (arc tube or filament), support hardware, enclosing envelope and base.
Lamp Lumen Depreciation, LLD (Lighting) - Information about the chosen lamp and its lumen depreciation and mortality are available from lamp manufacturers’ literature. Rated average life should be determined for the specific hours per start; it should be known when burnouts occur in the lamp life cycle. From these facts, a practical, group re-lamping cycle should be established. Based on the hours elapsed to lamp replacement, the LLD factor can be determined.
LAN - Local Area Network
Lateral Circuit - A tap-off line to take primary distribution from the main power line to a nearby load center.
Lateral Light Distribution - Lateral light distributions are classified by IES distribution Types I, II, III, IV and V. In general, the larger the number, the more is projected across the roadway. This allows the lighting designer to select the appropriate distribution pattern for a given roadway width.
Lay Direction - 1) The direction in which the wires of a conductor are twisted. 2) The twist of conductors in a cable.
Lay Length - The distance required to complete one revolution of helically laid strands of wires.
LDD - Luminaire Dirt Depreciation Factor
Lead - The condition where the current precedes in time with repect to the voltage in an ac circuit (for example, a capacitive load).
Lead Acid (Battery) - Term used in conjunction with a cell or battery that utilizes lead and lead peroxide as the active plate materials in a diluted electrolyte solution of sulfuric acid and water. The nominal cell voltage is 2.1 volts.
Lead Acid Battery - The assembly of one or more cells with an electrolyte based on dilute sulfuric acid and water, a positive electrode of lead dioxide and negative electrodes of lead. Lead Acid batteries all use the same basic chemistry. The positive plate is comprised of lead dioxide and the negative of finely divided lead. Both of these active materials react with the sulfuric acid electrolyte to form lead sulfate on discharge. The reaction is reversed on recharge. Batteries are constructed with lead grids to support the active material and individual cells are connected to produce a battery in a plastic or glass case.
Lead Dioxide (Battery) - The higher oxide of lead present in charged positive plates. It is frequently referred to as lead peroxide.
Lead Peroxide - See Lead Dioxide.
Lead Sulfate - A lead salt formed by the action of sulfuric acid on lead oxide during paste mixing and formation. It is also formed electromechanically when a battery is discharged.
LED - Light Emitting Diode
Light - Energy that is capable of exciting the retina and producing a visual sensation.
Light Loss Factor (LLF) - A factor used in calculating illuminance after a given period of time and under given conditions. It takes into account temperature and voltage variations, dirt accumulation on luminaire and lit surfaces, lamp depreciation, maintenance procedures and atmospheric conditions. It was formerly referred to as maintenance factor.
Light Traffic - A grade level Box or Cover rating. See "Incidental Light Traffic".
Lighting Arrester - A device that protects power lines and equipment against high voltage lighting surges and switching surges. Connected from line to ground potential, the device has a very high resistance to current flow at normal voltages but when a very high voltage surge hits it, it becomes a very low resistance, passing damaging surges and current to ground.
Lighting Maintenance Factor (MF) - The result of time-dependent depreciation effects must be considered in the initial design. Regular maintenance is particularly important with regard to energy conservation and these plans, once incorporated into the design, should be carried out or the system will not perform as expected.
Lightning & Switching Impulses - A distinction is made between Lightning and Switching impulses on the basis of duration of the wave front. Impulses with wave-front durations of up to a few tens of microseconds are in general considered to be lightning impulses. Those having durations of tens to thousands of microseconds are considered to be switching surges.
Line - Refers to the conductor in an overhead or underground distribution or transmission line.
Line Hose - A rubber dielectric cover for conductor that is used to electrically isolate a worker from an energized conductor. Line hose is made by W.H. Salisbury & Company.
Liner - Cloth gloves used to line the inside of a rubber insulating glove.
LLF (Lighting) - Light Loss Factor
Load - 1) The amount of electrical power required by connected electrical equipment. 2) The total impedance of all the items in the output circuit.
Load Loss - See "Coil Loss".
Loadbreak - Refers to a group of rubber insulating products used to electrically connect apparatus with which load can be separated manually. Loadbreak products are manufactured by T&B Elastimold.
Local Roadway (Lighting) - Roadways used primarily for direct access to residential, commercial, industrial or other abutting properties. They do not include roadways carrying through traffic. Long local roadways will generally be divided into short sections by collector roadway systems.
Long Distribution (Lighting) - A luminary is classified as having a long light distribution when its max candlepower point falls between 3.75MH – 6.0MH TRL. The maximum luminaire spacing-to-mounting height ratio is generally 12.0 or less.
LPW - Lumens Per Watt
Lube - Slang for "Cable Pulling Lubricant".
Lumen - Standard unit of measure for light flux or light energy. Lamp light output is measured in Lumens.
Lumens Per Watt (LPW) - The ratio of light energy output (Lumens) to electrical energy input (Watts).
Luminaire - A complete lighting unit consisting of a light source with a means of distribution (reflector and/or refractor), lamp positioning (socket), lamp protection (housing) and a provision for power connection.
Luminaire Dirt Depreciation (LDD) - The accumulation of dirt on luminaires results in a loss of light output on the road. This loss is known as the LDD factor and is determined by estimating the dirt category from the graph below. From the appropriate dirt condition curve and the proper elapsed time of the planned cleaning cycle, the LDD factor is then found.
Luminaire Dirt Depreciation Factor (LDD) - The multiplier to used in illuminance calculations to relate the inital illuminace provided by clean, new luminaires to the reduced illuminace that they will provide due to dirt collection on the luminaires at the time at which it is anticipated that cleaning procedures will be instituted.
Luminance - In a direction and at a point of a real or imaginary surface - The quotient of the luminous flux at an element of the surface surrounding the point, and propagated in directions defined by an elementary cone containing the given direction, multiplied by the solid angle of the cone and the area of the orthogonal projection of the element of the surface on a plance perpendicular to the given direction.
Lux - The SI unit of illuminance. One lux is one lumen per square meter.

M
Major Roadway (Lighting) - That part of the roadway system that serves the principal network for through-traffic flow. The routes connect areas of principal traffic generation and important rural highways entering the city.
MCC - Motor Control Center
MCCB - Molded Case Circuit Breaker
Medium Distribution (Lighting) - A luminary is classified as having a medium light distribution when its max candlepower point falls between 2.25MH - 3.75MH TRL. The maximum luminaire spacing-to-mounting height ratio is generally 7.5 or less.
Medium Voltage - An electrical system or cable designed to operate between 1kv and 38kv.
Megohmmeter - A testing device that applies a dc voltage and measures the resistance (in millions of ohms) offered by conductor's or equipment insulation.
Melt Time - The time needed for a fuse element to melt, thereby initiating operation of the fuse. Also known as Fuse Melt Time.
Mercury Vapor Lamp (MV) - An HID light source in which the arc tube's primary internal element is Mercury Vapor.
Messenger - A bare wire used to support power or communications cables suspended overhead.
Metal Clad (Switchgear) - An expression used by some manufactures to describe a category of medium voltage switchgear equipment where the circuit breakers are all enclosed in grounded, sheet-steel enclosures. Such enclosures may be suitable for indoor use or may be enclosed in an integral weatherproof housing for installation out of doors.
Metal Enclosed (Switchgear) - An expression used by some manufacturers to describe a category of low voltage, 600 volt class switchgear equipment, where the circuit breakers are all enclosed in grounded, sheet-steel enclosures. Such enclosures normally are suitable only for indoor use.
Metal Halide Lamp (MH) - An HID light source in which the arc tube's primary internal element is Mercury Vapor in combination with Halides (salts or iodides) of other metals such as Sodium or Scandium.
MHR (Lighting) - Mounting Height Ratio
Micro- - One-millionth
Mil - One-thousandth of an inch (0.001 inch)
Momentary Rating - The rating of a device to withstand momentary, very high current, without incurring damge.
Mortality Curve - A graphic representation of lamp burnout as a function of time.
MOV - Metal Oxide Varistor
MRO - Maintenance and Repair
MTW - Machine tool wire, used for electrical connections inside equipment.
MV - See "Medium Voltage".
MVA - Apparent Power expressed in Million Volt-Amps.
MW - Mega Watt, one million watts.
MWH - Mega Watt Hour, the use of one million watts for one hour.

N
NAICS - North American Industry Classification System. This is used in place of the PPI (Producer Price Index) system.
Nameplate Rating - The normal maximum operating rating applied to a piece of electrical equipment. This can include Volts, Amps, horsepower, kW, or any other specific item specification for the equipment.
NEC - National Electrical Code (NFPA-70).
NEMA - National Electrical Manufacturers Association. NEMA is located at 2101 L Street N.W., Washington, DC, 20037.
Neutral Conductor - In multiphase circuits, the conductor used to carry unbalanced current. In single-phase systems, the conductor used for a return current path.
Nickel Cadmium Battery - The assembly of one or more cells with an alkaline electrolyte, a positive electrode of nickel oxide and negative electrodes of cadmium.
No Load Loss - See "Core Loss".
Nominal - The normal operating value.
Nominal Capacity (Battery) - A designation by the battery manufacturer which helps identify a particular cell model and also provides an approximation of capacity. It is normally expressed in ampere-hours at a given discharge current.
Nominal Voltage (Battery) - Voltage of a fully charged cell or battery when delivering rated capacity at a specific discharge rate. The nominal voltage per cell is 2V for Lead Acid, 1.2V for Nickel-Cadmium, 1.2V for Nickel Metal Hydride and 3.9V for Lithium Ion (small cells only).
Non-cutoff (Lighting) - Luminaire light distribution is classified as non-cutoff when there is no candlepower limitation in the zone above max candlepower.
Non-Halogen Ethylene Copolymers - Non-Halogen Ethylene Copolymers combine attributes of polyethylene and polypropylene to produce cable insulating and jacketing compounds with superior fire protection. Unlike other ethylene compounds, these do not contain chemicals from the Halogen group of elements and do not give off toxic or acid byproducts when burned.
Non-Loadbreak - Refers to a group of rubber insulating products that cannot be separated under load. Also see Loadbreak.
Nylon - For Wire and Cable applications, Nylon, a thermoplastic compound, is used exclusively as a jacketing material. Nylon Jackets provide the insulation system a high degree of mechanical and chemical protection.

O
Occasional Traffic - Refers to a grade level Reinforced Polymer Concrete or Fiberglass Reinforced Plastic Box or Cover load rating of 20,800lbs. This rating is derived from double wheel loading of 16,000 lbs with an impact factor of 30% added (16000 x x1.30). Application is limited generally for use in Parking Lots, Driveways and other Non-Street areas where vehicle traffic is expected. Meets the base loading of AASHTO H-20 but not listed as such to prevent use in streets.
Off Peak Power - Power supplied during designated periods of low power system demand.
Ohm - A unit of electrical resistance defined as the resistance of a circuit with a voltage of one volt and a current flow of one ampere.
Ohm's Law - E=IR; I=E/R; R=E/I; Where E = Voltage impressed on a circuit, I = current flowing in a circuit and R = circuit resistance.Ohm's Law is used for calculating voltage drop, fault current and other characteristics of an electrical circuit.
Oil Breakers - A type of high voltage circuit breaker using mineral oil as both an insulator and an interrupting medium. Typically, these units were produced for use at voltages from 35 kV to as much as 345 kV. Generally, these are older types and no longer produced for new installations.
Open Link - A fuse used on overhead electrical distribution systems that is held in place by two springs. This device and its holder have generally been replaced by Fused Cutouts where the fuse element in an arc tube.
Open-Circuit Voltage (Battery) - The voltage of a cell or battery when it is not delivering or receiving power.
Operating Current - The current used by a lamp and ballast combination during normal operation.
Outage - The state of a component or part of a power system that is not available for service because of some event associated with the component of power system.
Outage, Forced - 1. An outage that results from conditions directly associated with a power system component requiring that it be taken out of service either automatically or after switching operations can be performed. 2. An outage by improper operation of equipment or by human error.
Outage, Scheduled - An outage that results from intentionally taking a power system out of service, normally for maintenance or replacement.
Overcharge (battery) - The forcing of current through a cell after all the active material has been converted to the charged state (after 100% charged). The result will be the decomposition of water in the electrolyte into hydrogen and oxygen gas
Overload - The specified maximum magnitude of the input quantity that can be applied for a specified period of time without causing damage.
Overrange - The specified maximum operating point for which the stated accuracy condition applies.
Oxygen Recombination - The process by which xygen generated at the positive plate during charge reacts with the pure lead material of the negative plate and in the presence of sulfuric acid and reforms water.

P
Parkway - Sometimes referred to as a rating for Grade Level Boxes or Covers rating. See "Incidental Light Traffic".
Pasted Plate (Battery) - Paste in which the active material is applied as a paste to a conductive grid.
PE - Polyethylene. PE is an thermoplastic wire and cable insulating material that is also used for cable jacketing.
Peak to Peak - The amplitude of the ac wave form from its positive peak to its negative peak.
Pedestrian Loading - Refers to a grade level Reinforced Polymer Concrete or Fiberglass Reinforced Plastic Box or Cover loading applied by pedestrian traffic.
Pedestrian Walkway (Lighting) - A public walk for pedestrian traffic not necessarily within the right-of-way for vehicular traffic. Included are skywalks (pedestrian overpasses), subwalks (pedestrian tunnels), walkways giving access to parks or block interiors and mid-block street crossings.
PF - Power Factor
Phase Angle - The angular displacement between a current and voltage waveform, measured in degrees or radians.
Pilot Line - A cord or rope used to pull a heavier rope that will be used to pull a conductor into place.
Plante Plate (Battery) - Plate made of pure lead.
Plate (Battery) - The electrode of a cell consisting of a current collector and a positive or negative active material.
Polarity - 1) The electrical Term used to denote the voltage relationship to a reference potential (+). 2) With regard to Transformers, Polarity is the indication of the direction of the current flow through the high voltage terminals with respect to the direction through the low voltage terminals.
Pole Spacing (Lighting) - (ILL x CU x LLF)/(AMF x RW)
Polyethylene - A thermoplastic material composed of ethylene polymers. Polyethylene has excellent electrical and mechanical properties and is used an an insulating material in cable.
Polymer Concrete - Also referred to as Reinforced Polymer Mortar (RPM). Polymer Concrete material consists of calcareous and siliceous stone, glass fibers and thermoses polyester resin. Polymer concrete can be used in the manufacture of equipment pads, grade level boxes and box covers.
Polyvinyl Cloride - Polyvinyl Cloride. PVC, a thermoplastic compound, is a comonly used Wire and Cable insulation and jacketing material.
Pot - 1) Slang for an overhead transformer. 2) Short for "Potential".
Potential - The voltage in a circuit. Reference is usually to the AC Voltage.
Potential Transformer - A transformer used measure the amount of Voltage in a circuit. Its primary is rated in excess of the expected voltage of the circuit and the secondary will normally be rated at 120 volts being equal to the nominal full primary voltage.
Pothead - Slang for a device used to transition an overhead conductor to underground. Potheads are normally porcelain and have been largely replaced with non-ceramic, synthetic rubber, terminators of the type manufacturered by Thomas & Betts Elastimold.
Power - Rate at which energy is released or consumed, expressed in watts.
Power Exchange - See California Power Exchange.
Power factor - The ratio of the effective power (watts) to the apparent power (volt-amps). Equal to the cosine of the phase angle for singlephase or 3-phase, 3-wire systems
Power Factor - The ratio of energy consumed (watts) versus the product of input voltage (volts) times input current (amps). In other words, power factor is the percentage of energy used compared to the energy flowing through the wires. Adding capacitors to the system changes the inductive effect of the ballast coils, converting a Normal Power Factor (NPF) to a High Power Factor (HPF) system.
Power Marketer - An entity that takes title to electric power and then resells the power to end-use customers. This "middleman," which acts for itself in negotiating contracts, purchases, or sales of electrical energy, is required to meet two FERC tests to be certified as a power marketer: 1) show lack or adequate mitigation of transmission power; and 2) prove non-dominance of market power.
Power Transformer - A large transformer, generally larger than 1,000 kVA in capacity.
Protective Device Numbers, ANSI - 2 Time-delay, 21 Distance, 25 Synchronism-check, 27 Undervoltage, 30 Annunciator, 32 Directional power, 37 Undercurrent or underpower, 38 Bearing, 40 Field, 46 Reverse-phase, 47 Phase-sequence voltage, 49 Thermal, 50 Instantaneous overcurrent, 51 AC time overcurrent, 59 Overvoltage, 60 Voltage balance, 63 Pressure, 64 Apparatus ground, 67 AC directional overcurrent, 68 Blocking, 69 Permissive, 74 Alarm, 76 DC overcurrent, 78 Out-of-step, 79 AC reclosing, 81 Frequency, 85 Carrier or pilot-wire, 86 Lock out, 87 Differential, 94 Tripping,
PS (Lighting) - Pole Spacing
psi - Pounds per square inch
PT - See "Potential Transformer".
PUC - Public Utility Commission
Pull - A noun referring to the installation of one or more cables.
Pull Tension - The tension in pounds or kilograms required to pull a cable or wire into a duct or conduit or into an overhead location.
Pulling - The act of installing one or more cables.
PVC - Polyvinyl chloride, a common thermoplastic insulation and jacketing material used to manufacture building wire and other types of wire and and cable. It is also used in the manufecture of plastic conduit.
PX - See California Power Exchange.

R
Raceway - An enclosed channel designed expressly for holding conductors and cables, including conduit and tubing, wireways, and busways.
Range - Nominal operating limits, specified by the lowest calibration point to the highest calibration point.
Rated Capacity (Battery) - The number of Amp-Hours a battery can deliver under specific conditions (rate of discharge, end voltage, temperature).
Rated Lamp Life - With regard to lighting, the point in time when 50% of a statistically significant number of lamps has failed.
Rated Output - The output at standard calibration.
Reactance - The opposition of inductance and capacitance to alternating current equal to the product of the sine of the angular phase difference between the current and voltage.
Reactive Power - A component of apparent power (volt-amps) which does not produce any real power (watts) transfer (the sine of the phase angle between the current and the voltage).
Reading - The expected output at a given input value.
Real Power - The average value of the instataneous product of volts and amps over a fixed period of time in an AC circuit.
Recloser - A switching device that rapidly recloses a power switch after it has been opened by an overload. In reclosing the power feed to the line, the device tests the circuit to determine if the problem is still there. If not, power is not unnecessarily interrupted on the circuit.
Recombination (Battery) - State in which the hydrogen and oxygen gasses normally formed within the battery cell during charging are recombined to form water.
Reel - A cylinder device used to hold wire and cable until installed. There are standard reel sizes that are used in the electrical industry that are either wood (non-returnable) or steel (returnable).
Reflector - A device used to re-direct the luminous flux from a light source by the process of reflection.
Refractor - A device used to re-direct the luminous flux from a light source by the process of refraction.
Regulating Transformer - A transformer used to vary the voltage, or phase angle, of an output circuit. It controls the output within specified limits and compensates for fluctuations of load and input voltage.
Regulation - See "Voltage Regulation".
Regulator - A device that is used to control the voltage of a circuit by raising and lowering it. Howard Incustries is a manufacturer of Regulators.
Reinforced Polymer Mortor - Also referred to as "RPM". See "Polymer Concrete".
Relays - Distance - Relays used on transmission lines that use a variety of sensors and measurements to determine when an unusual condition exists at some distance, out on the transmission circuit.
Relays - Over-current - Protective relays used on power systems that detect excessive currents and send signals to protective devices, such as power circuit breakers.
Relays - Voltage - Protective relays used on power systems that detect when line voltage has gone outside of an acceptable range, either up or down, and send a signal to a protective device or system.
Resealable Cap (Battery) - A safety vent valve which is capable of closing after each pressure release from within a cell.
Residential (Lighting) - A residential development, or a mixture of residential and small commercial establishments, characterized by few pedestrians during nighttime hours. This definition includes area with single-family homes, townhouses, and/or small apartment buildings.
Resistance - The opposition to current flow, expressed in ohms.
Response Time - The time for a measurement device's output signal to reach 99% of its final value after a step change in the applied input.
RHH - A rubber or XLPE insulated conductor designed to be used at operating temperatures up to 90 degrees Celsius in dry locations.
RHH-2 - A rubber or XLPE insulated, moisture resistant conductor designed to be used at operating temperatures up to 90 degrees celsius in dry and wet locations.
Ridge Pin - A device that allows the mounting of a pin type insulator to a pole. The ridge pin is bolted to the top of the pole and the insulator is screwed onto the threads at its top.
Ripple - The magnitude of AC fluctuation in a DC signal, after filtering. Ripple is usually expressed as a percentage of rated output.
Riser Pole - A pole used to transition from overhead and underground cables.
RMS - see "Root-Mean-Square".
Root-Mean-Square - The effective value of alternating current or voltage. The RMS value equates an ac current or voltage to a dc current or voltage that provides the same power transfer.
RPM - Reinforced Polymer Mortar. See "Polymer Concrete".
RTO - Regional Transmission Organization.
RTU - Remote Terminal Unit
RW (Lighting) - Roadway Width

S
Sag - The amount of vertical displacement of an overhead conductor between support points. Sag is a consideration when designing a pole or tower line and will be a determining consideration in the overall height of the structure. Sag varies with the temperature of the conductor and charts are available to determine it.
SAIDA - A distribution system reliability measure of the system average interruption duration index. It is commonly measured in customer minutes of interruption and is commonly used as an electric service performance metric.
SAIFI - A distribution system reliability measure of the system average interruption frequency index. It measures sustained outages and interruptions and is a metric for the entire power system.
Scaling Resistor - A resistor added to an output circuit of measurement equipment to provide a scaled voltage output. The output is not a "true" voltage output and may be susceptible to loading errors.
Schematic Diagram - A diagram which shows, by means of graphic symbols, the electrical connections and functions of a curcuit.
Sealed Cell (Battery) - Cells that are free form routine maintenance and can be operated without regard to position.
Self Discharge (Battery) - The decrease in the state of charge of a battery or cell, over a period of time, due to internal electro-chemical losses.
Semi-Con - The semi-conducting material extruded over the insulation on medium voltage insulated cables. It is extruded onto the cable, normally at the same time as the insulation. Southwire Company manufacturers medium voltage cables. Speed Systems manufactures stripping tools to remove the semi-con layer. American Polywater manufactures cleaners to remove the semi-con residue left after stripping.
Semi-cutoff (Lighting) - Luminaire light distribution is classified as semi-cutoff when the candlepower per 1000 lamp lumens does not numerically exceed 50 (5.0%) at an angle of 90 degrees above nadir (horizontal), and 200 (20%) at a vertical angle of 80 degrees above nadir. This applies to any lateral angle around the luminaire.
Separator (Battery) - A porous, insulating material placed between plates of opposed polarities, to prevent internal short circuits.
SER - Service Entrance Cable.
Service Drop - An overhead service conductor run from a utility company pole to the point of connection to the building's service entrance conductors.
Service Entrance Cable - The conductors that connect the service conductors (drop or lateral) to the service equipment of the building.
Service Life (Battery) - The total period of usefull life of a battery, normally expressed in the total number of Charge/Discharge cycles.
SEU - Service entrance cable.
Short Circuit - 1. A load that occurs when at ungrounded conductor comes into contact with another conductor or grounded object. 2. An abnorman connection of relatively low impedance, whether made intentionally or by accident, between two points of different potential.
Short Distribution (Lighting) - A luminary is classified as having a short light distribution when its max candlepower point falls between 1.0MH - 2.25MH TRL. The maximum luminaire spacing-to-mounting height ratio is generally 4.5 or less.
Shotgun Stick - A specialized hot stick that allows the capture of certain types of clamps and devices in its hook. It is also called a "Grip All" stick.
SI - See "International System of Units".
Sidewalk (lighting) - Paved or otherwise improved areas for pedestrian use, located within public street rights-of-way also containing roadways for vehicular traffic.
Sidewall Pressure - The force exerted on a cable as it is dragged around a bend. The longer the pull and the tighter the bend radius, the higher the sidewall pressure will become. High sidewall pressure damages cable. There is a higher chance of destroying cable by high sidewall pressure than by high tensile tension. Electrical cable manufacturers' specifications limit sidewall pressure to a range of 300 - 1500 lbs/ft, depending on cable type. There are three ways to reduce sidewall pressure while pulling cable with bends: shorten the pull, enlarge the bend radius, or use a high performance lubricant. Polywater’s “Pull Planner 2000” software package automatically calculates sidewall pressure for each segment of a cable pull (a "segment" contains one straight section and one bend). This allows a designer to play "what if," easily changing pull parameters and instantly seeing the affect on sidewall pressure. For a copy of American Polywater’s Pull Planner 2000, contact Young & Company.
Single-Phase - This implies a power supply or a load that uses only two wires for power. Some "grounded" single phase devices also have a third wire used only for a safety ground, but not connected to the electrical supply or load in any other way except for safety grounding.
Sintered Plate (Battery) - The plate of a alkaline cell, the support of which is made of sintered metal powder, and into which the active material is introduced.
Skin Effect - In an ac system, the tendency of the outer portion of a conductor to carry more of the current as the frequency of the ac increases.
Sky Wire - See "Static Wire"
Sleeve - See "Compression Splice".
Soap - Slang for "Cable Pulling Lubricant".
Spacing-to-Mounting Height Ratio - Ratio specification used to insure that fixtures are adequately spaded, thus preventing "hotspots"
Span - 1) Refers to the distance between two poles of a transmission or distribution line. 2) The algebraic difference between the upper and lower values of a range.
Spark Test - A high-voltage test performed on certain types of conductor during manufacture to ensure the insulation is free from defects.
Specific-Gravity (Battery) - The weight of the electrolyte compared to the weight of an equal volume of pure water. It is used to measure the strength or percentage of sulfuric acid in th electrolyte.
Spill Light - Unwanted light directed onto a neighboring property. Also referred to Light Trespass.
Stability - The ability of a device to maintain its performance characteristics over a specified period of time.
Stage 3 Emergency - In the state of California, if power reserves ever fall below 1.5 percent, Cal-ISO, the independent system operator in California, will declare a Stage 3 emergency and the state's investor-owned utilities, may be ordered to immediately reduce the demand for electricity. At that point, the utilities will implement a series of temporary, controlled rotating power outages.
Standard calibration - The nominal point at which a measurement device is adjusted.
Starter - A device used in conjuction with a ballast for the purpose of starting an electric discharge lamp.
Starting Current - Current required by the ballast during initial arc tube ignition. Current changes as lamp reaches normal operating light level.
Starved Cell (Battery) - A cell containing little or no free fluid electrolyte solution. This enables gasses to reach electrode surfaces readily, and permits relitive high rates of recombination.
State of Charge (Battery) - The available amp-hours in a battery at any point of time. State of Charge is determined by the amount of sulfuric acid remaining in the electrolyte at the time of testing or by the stabilized open circuit voltage.
Static Wire - A wire placed above the phase wires of a distribution of transmission circuit to protect against lightning. It is normally galvanized or aluminized steel.
Stick - See Hotstick.
Stinger - Slang for the wire connecting a fused cutout or switch to a transformer bushing.
Strand - One of the wires that made up a stranded conductor.
Stranded Conductor - A conductor made by twisting together a group of wire strands.
Stranded Cost - Assets owned by an investor owned electric utility, normally costs associated with generation-related assets and state-mandated contracts with nonutility generators that may now be uneconomic and unrecoverable in the restructured electric utility industry.
Stringing - The act of installing overhead electrical wire or conductor.
Stringing Block - A sheave used to support and allow movement of a cable that is being installed. These are normally used overhead but there are also specialized designs used at the entrance to a conduit system. Stringing blocks are manufactured by Bethea.
Stringing Dolly - See "Stringing Block".
Sub-Transmission System - A high voltage system that takes power from the highest voltage transmission system, reduces it to a lower voltage for more convenient transmission to nearby load centers, delivering power to distribution substations or the largest industrial plants. Typically operating at voltages from approximately 35 kV to 100 kV.
Sulfation (Battery) - The formation of lead sulfate of such physical properties that it is extreemly difficult, if not impossible, to reconvert it to active material.
Sulfur-Hexafluoride (SF6) - A very dense, inert, non-conducting gas used inside high voltage equipment to insulate conducting components from surfaces at ground petential. It also is used as an interrupting medium in high voltage circuit breakers.
Surge Arrester - See Arrester.
Surge Withstand - A measure of an electrical device's ability to withstand high-voltage or high-frequency transients of short duration without damage.
Surge Withstand Capability (swc) Test - The SWC test wave is an oscillatory wave, frequency range of 1-1.5 MHz, voltage range of 2.5-3 kV crest value of first peak, envelope decaying to 50% of the crest value of the first peak in not less than 6 micro seconds from the start of the wave. The source impedance is from 150-200. The wave is to be applied to a test specimen at a repetition rate of not less than 50 tests per second for a period of not less than two seconds.
Sweeling (Battery) - The swelling or bulging of a battery case that results from cell vents not allowing enough internal pressure to be relieved.
Switch, Network - A Switch connects Client systems and servers together to create a nework.
Switchgear - A general term covering switching and interrupting devices and their combination with associated control, metering, protective and regulating devices. Also, the assemblies of these devices with associated interrconection, accessories, enclosures and supporting structure, used primarily in connection with the generation, transmission, distribution and conversion of electric power.
Switching Impulses - see "Lightning and Switching Impulses".
Switching Surges - High voltage spikes that occur when current flowing in a highly inductive circuit, or a long transmission line, is suddenly interrupted. As the magnetic field about the inductive conductor collapses, a brief by very high voltage can be generated at the terminal point of the circuit.

T
T&D - Transmission and Distribution.
Tag Line - A rope used to control the position of equipment being lifted. This is not to be confused with the rope used to actually lift the equipment.
Temper - The softmess of a metal; terms such as soft-drawn, dead soft, annealed, and semi-annealed are used to decribe tempers used for conductor metals.
Temperature Rise - The increase in temperature that results when electrical load is carried by electrical equipment.
Tensile Strength - The greatest longitudinal force that a substance can bear without tearing apart or rupturing; also called ultimate tensile strength.
Tension - The force in pounds of kilg grams on a conductor installed overhead. Too much tension on an overhead line can contribute to mechanical failure.
Termination - 1) The act of preparing the connection or transition of an insulating cable. 2) The device that transitions an underground cable to an overhead cable or wire.
Speed Systems manufactures tools used to terminate cables. Thomas & Betts Elastimold manufactures Terminators
Terminator - A device used to transition between overhead and underground, medium and high voltage conductors.
TFE - A Heat-resistant insulation compound made with tetrafluoroethylene (Teflon).
Thermal Expansion - The expansion of a material when subjected to heat.
Thermoplastic - A plastic compound that will soften and melt with sufficient heat. Thermoplastic insulation compounds are used to manufacture certain types of electrical cables.
Thermoset - A plastic compound that will not remelt. Thermoset insulation compounds are used to manufacture certain types of cables.
THHN - A thermoplastic-insulated, nylon-jacketed conductor designed for use in dry locations and an operating temperature of up to 90 degrees Celsius
Three Wire - See Delta.
Three-Phase - Multiple phase power supply or load that uses at least three wires where a different voltage phase from a common generator is carried between each pair of wires. The voltage level may be identical but the voltages will vary in phase relationship to each other by 120 degrees.
Thumper - A high voltage device used to locate an underground cable fault. The device applies a high voltage to the faulted cable with a resulting discharge to ground at the location of the fault. When the discharge occurs, there is an audible "Thump" which is used to locate the fault. Hipotronics manufactures "Thumpers".
THW - A thermoplastic insulated, moisture resistant conductor designed for use in wet or dry locations and an operating temperature of up to 75 degrees Celsius.
THWN-2 - A thermoplastic insulated, nylon-jacketed, moisture resistant conductor designed for use in wet or dry locations and an operating temperature of up to 75 degrees Celsius.
Tie - A wire device that connects a conductor to an insulator. Factory formed ties are manufactured by Preformed Line Products Company.
Transco - A for profit Power Transmission Company.
Transducer - A device for converting an electrical signal into a usable direct current or voltage for measurement purposes.
Transducer Factor - The product of the current transformer ratio (CTR) and the voltage transformer ratio (VTR). Also called the power ratio.
Transformer - An electro-magnetic device used to change the voltage in an alternating current electrical circuit.
Transformer Bank - See "Bank".
Transformer Insulation - This is the material that is used to provide electrical insulation between transformer windings at different voltage levels and also between the energized parts and the metal tank of the transformer. Generally, for large transformers used in power applications, this is a combination of Kraft paper and mineral oil; however, in indoor building applications, transformers also may be insulated with plastic materials.
Transformer Ratio - When used in reference to Instrument Transformers, this is simply the ratio of transformation of one or more transformers used in the circuit. If both Cts and VTs are included, the transformer ratio is the product of the CT and the VT. For example, assume a VT with a ratio 10:1 and a CT with a ratio of 20:1, then the combined transformer ratio is 10 x 20 = 200:1.
Transformer Voltage Regulators - Mechanisms that use multiple voltage taps on a transformer-like device to adjust voltage on a power line. As the voltage increases or decreases on the circuit, sensors in the voltage regulator call for the input or output of the regulator to connect to different voltage taps on the transformer winding. This adjusts the output voltage on the line to an acceptable level.
Transmission System - Normally, the highest voltage network of an electric utility system. This is the portion of the system that carries high power over the longest distances. Typically operating at voltages in excess of 100 kV, and most usually at 200 kV and above.
Traveler - See "Stringing Block".
Treeing - Water treeing is a form of cable insulation degradation where micochannels, that often appear as a tree-like structure in the insulation, develop due to a complex interaction of water, electrical stress, impurities and imperfections. The tree-like channels grow slowly over time, weakening the insulation and, in some cases, lead to cable failure.
Trickle Charge (Battery) - A continuous low rate charge that compensates for the self discharge rate of a battery. Also known as Float Charge.
True RMS Amps - 1) The effective value of an ac signal. For an amp signal, true RMS is a precise method of stating the amp value regardless of waveform distortion. 2) An AC measurement which is equal in power transfer capability to a corresponding dc current.
True RMS volts - 1) The effective value of an ac voltage value regardless of the waveform distortion. 2) An ac measurement which is equal power transfer capability to a corresponding dc voltage.
TRXLP - Tree Retardant Cross Linked Polyethylene. A thermoset plastic compound that is used for insulation of wire and cable contaning an anti-treeing compound.
Tubular Plate (Battery) - A positive plate which is composed of asembly of porous tubes of perforated metal or tissure with or without a central current collector spine. The active material is placed within the tube.
Tungsten Halogen Lamp - A gas-filled tungsten halogen lamp containing a certain proportion of halogens.
TW - 1) A thermosplastic insulated, moisture resistant conductor designed for use in wet or dry locations and an operatating temperature of up to 60 degrees celsius. 2) Trapezoidal Wire. Built as ACSR-TW or ACSS-TW, Trapezoidal Wire uses trapezoidal formed strands in its construction to reduce overall diameter of the finished cable.
Twenty A - See 20A.
Twenty B - See 20B.
Twenty C - See 20C.

U
UD - Underground Distribution
UF - A thermoplastic insulated, underground feeder conductor or cable designed for use in wet locations, including direct burial.
UHV - see "Ultra High Voltage".
UL - Underwriters Laboratories, Inc. UL is located at 333 Pfingsten Road, Northbrook, IL 60062.
Ultra High Voltage (UFV) - Electric systems in which the Root-Mean-Square ac voltage exceeds 800,000 volts.
Unbalanced Loads - Refers to an unequal loading of the phases in a polyphase system.
Underground Residential Distribution - Refers to the system of electric utility equipment that is installed below grade.
Underground Utility Structure - An enclosure for use underground that may be either a handhole or manhole.
Unidirectional Unit - Allows inputs to be measured in one direction only. The stated output range indicates the minimum and maximum input levels.
Universal Bushing Well - This 200 amp rated component is used as part of a system to terminate medium voltage cables to transformers, switchgear and other electrical equipment. Universal Bushing Wells are manufactured by the Elastimold Division of Thomas & Betts.
UPS - Uninterruptable Power Supply
URD - Underground Residential Distribution.
USE - Underground Service Entrance conductor or cable.
USMA - Utility Supply Management Alliance, a utility industry conference held annually that is focused on the supplier/customer relationship.

V
V - Voltage; Volt.
VA - Electrical capacity or electrical load, expressed as Volts x Amps.
Vacuum Circuit Breakers - Circuit breakers, normally applied at medium voltages, that use vacuum interrupters to extinguish the electrical arc and shut-off flowing current.
Vacuum Interrupter - A sealed "bottle" containing contacts of a switch inside a very high vacuum. When the contacts are parted in the vacuum, as there is no gas in the bottle to ionize, the current flow is quickly extinguished.
Valve Regulated Sealed Cell (Battery) - A battery in which the cells are closed but have a valve which allows the excape of gas if the internal pressure exceeds a predetermined value (pressure).
VAR - Volt Ampere Reactive. Also see "Reactive Power".
Veiling Luminance - A luminance superimposed on the retinal image which reduces its contrast. It is this veiling effect produced by bright sources or areas in the visual field that results in reduced visual performance and visibility.
Vent Cap (Battery) - The plug on top of a cell that can be removed to check and change the level of the electrolyte.
Vent Valve (Battery) - A normally sealed mechanism which allows the controlled excape of gasses from within a cell.
Venting (Battery) - The release of gas from a cell, either controlled (through a vent) or accidental.
Volt - A unit of electromotive force. The electrical potential needed to produce one ampere of current with a resistance of one ohm.
Voltage Class - The general strength of electrical insulation on a device, determining the maximum continuous voltage that can be applied between the conducting parts and ground potential, without damaging the insulation.
Voltage Drop - The loss of voltage in a circuit when current flows.
Voltage Rating - The normal voltage to be applied to an electrical device to provide for proper operation.
Voltage Regulation - The maintenance of a voltage level between two established set points, compensating for transformer and/or line voltage deviation, caused by load current. The voltage change is affected by the magnitude and the power factor of the load current.
Voltage Spread - The difference between maximum and minimum voltages.
Voltage Transformer - Transformer used to accurately scale ac voltages up or down, or to provide isolation. Generally used to scale large primary or bus voltages to usable values for measuring purposes
Voltage Transformer Ratio - The ratio of primary volts divided by secondary volts
Voltage Withstand Test - A field or factory test in which a conductor or electrical equipment is subjected to a higher than normal ac or dc voltage to test its insulation system.
VT - See "Potential Transformer".

W
W.U.C. - See "Western Underground Committee"
WAPA - Western Area Power Administration
Watt - 1) A unit of power that considers both volts and amps equal to the power in a circuit in which a current of one ampere flows across a potential difference of one volt. 2) One joule/second.
Watt-Hour - 1) A unit of work equal to the power of one watt operating for one hour. 2) 3600 Joules.
Western Underground Committee - A committee of western based electric utility engineers that provides a forum for establishment of guides that provide options, recommendations and practices for its members. These guides are used to assist its members in preparing their own specifications and to make recommendations to specificying agencies.
Wire - A strand or group of strands of electrically conductive material, normally copper or aluminum.
Wire Lubricant - A chemical compound used to reduce pulling tension by lubricating a cable when pulled into a duct or conduit.
Work Plane - The plane at which work is usually done and on which the illuminance is specified and measured. Unless otherwise indicated, this is assumed to be a horizontal plane 30" above the floor.
WUC - See "Western Underground Committee".
Wye - A three phase, four-wire electrical configuration where each of the individual phases are connected to a common point, the "center" of the Y. This common point normally is connected to an electrical ground.

X
X - Reactance expressed in Ohms.
XHHW-2 - An XLPE insulated, moisture resistant conductor designed for use in wet or dry locations and an operating temperature of up to 90 degrees Celsius.
XLP - See "XLPE"
XLPE - Cross-Linked Polyethylene. A thermoset plastic compound that is used for insulation of wire and cable.

Y
Y - see "Wye".
Yield Strength - The force required to stretch a material.

Z
Zero Crossing - The point at which a sinsoidal voltage or current waveform crosses the zero reference axis.