Electrical glossary, English and Spanish
Texas lets you take the exam in Spanish, but the job site, the code book and your crew mix both languages. Every term has its pair in the other language, a short definition and, where it applies, the 2026 NEC article and a calculation drill.
Theory
- Alternating current (AC) Corriente alterna (CA)
- Current that reverses direction many times a second. In the United States it alternates at 60 hertz.
- Current Corrientealso: intensidad de corriente
- The flow of electric charge through a conductor, measured in amperes (A). Formulas write it as I.
- Delta connection Conexión deltaalso: triángulo
- A three-phase connection with the windings joined end to end in a closed loop. Line voltage equals winding voltage.
- Direct current (DC) Corriente directa (CD)also: corriente continua (CC)
- Current that flows in one direction only, as from a battery or a PV module.
- Efficiency Eficienciaalso: rendimiento
- Output power divided by input power, as a percentage. A motor that is 90% efficient turns 10% of its input into heat.
- Harmonics Armónicasalso: armónicos
- Currents at multiples of 60 Hz produced by nonlinear loads. On wye systems they can add up in the neutral, so the neutral may count as current-carrying.
- High leg Fase altaalso: fase de mayor tensión (high leg)
- On a 4-wire delta system with a center-tapped winding, the phase with the higher voltage to ground (about 208 V on a 240/120 V system). It must be marked orange.
- Impedance Impedancia
- The total opposition to alternating current, combining resistance and reactance, measured in ohms (Z).
- Nominal voltage Tensión nominalalso: voltaje nominal
- The round-number voltage used to name a system, such as 120/240 V or 480Y/277 V. Actual voltage varies a little above or below it.
- Ohm's law Ley de Ohm
- The rule that voltage equals current times resistance (E = I × R). Rearranged, it finds any one value from the other two.
- Parallel circuit Circuito en paralelo
- A circuit with several branches across the same voltage. Total resistance is lower than the smallest branch resistance.
- Power Potencia
- The rate at which electrical energy is used or delivered, measured in watts. In a resistive circuit, P = E × I.
- Power factor Factor de potencia
- The ratio of true power (W) to apparent power (VA), from 0 to 1. A low power factor means more current for the same useful work.
- Resistance Resistencia
- Opposition to current flow in a material, measured in ohms. Longer and smaller conductors have more resistance.
- Series circuit Circuito en serie
- A circuit with only one path, so the same current flows through every part. Total resistance is the sum of all resistances.
- Three-phase Trifásico
- A system with three voltages 120 degrees apart. Power formulas for it include the square root of 3 (1.732).
- True power Potencia realalso: potencia activa
- The power that does actual work or makes heat, measured in watts. It equals apparent power times power factor.
- Volt-ampere (VA) Voltampere (VA)also: volt-amperio
- The unit of apparent power, volts times amperes. Load calculations are done in VA, and transformers are rated in kVA.
- Voltage Voltajealso: tensión
- The electrical pressure that pushes current through a circuit, measured in volts (V). Formulas write it as E or V.
- Voltage to ground Tensión a tierraalso: voltaje a tierra
- For a grounded system, the highest voltage between a given conductor and the grounded point or conductor of the circuit.
- Wye connection Conexión estrellaalso: estrella (Y)
- A three-phase connection with one end of each winding joined at a common neutral point, as in 208Y/120 V or 480Y/277 V. Line voltage is 1.732 times phase voltage.
Conductors
- AC cable Cable armado tipo ACalso: BX
- Armored cable with a metal armor and an internal bonding strip, so the armor can serve as the equipment grounding path. Old trade name: BX.
- Adjustment factor Factor de ajustealso: derrateo, ajuste por agrupamiento
- A factor that lowers ampacity when more than three current-carrying conductors share a raceway or cable, because they heat each other. In the trade, applying it is called derating.
- Ambient temperature correction Corrección por temperatura ambientealso: factor de corrección
- A factor that lowers ampacity when the surrounding air is hotter than the 30°C (86°F) the ampacity table assumes.
- American Wire Gauge (AWG) AWG (calibre)also: calibre americano de conductores
- The US system of wire sizes. Smaller numbers are larger wires, and sizes above 4/0 AWG are given in kcmil.
- Ampacity Ampacidadalso: capacidad de conducción de corriente
- The most current a conductor can carry continuously under its conditions of use without going over its temperature rating.
- Circular mil Mil circularalso: circular mil (cmil)
- The area of a circle one mil (0.001 inch) across. Conductor areas in circular mils are used in voltage drop formulas.
- Conductor color code Código de colores de los conductores
- NEC identification rules: white or gray for the grounded conductor, green, green-yellow or bare for equipment grounding, and orange for a high leg.
- Current-carrying conductor Conductor portador de corriente
- A conductor counted for adjustment factors. Equipment grounding conductors never count, and a neutral counts only in certain cases.
- Flexible cord Cordón flexiblealso: cable de uso rudo
- A flexible cable for connecting portable equipment and appliances. It cannot be used as a substitute for permanent wiring.
- Insulation Aislamiento
- The nonconducting layer around a conductor. Its letter type tells the temperature rating and where the wire may be used.
- Insulation temperature rating Temperatura nominal del aislamiento
- The highest temperature an insulation can stand continuously: 60°C, 75°C or 90°C, matching the columns of Table 310.16.
- K constant Constante Kalso: resistividad del conductor
- The resistance of one circular-mil-foot of conductor, used in VD = 2KIL ÷ cmil. Common values are 12.9 for copper and 21.2 for aluminum.
- kcmil Kcmilalso: MCM
- Thousands of circular mils, the unit for conductors larger than 4/0 AWG (older term: MCM). A 250 kcmil conductor has 250,000 circular mils.
- MC cable Cable con armadura metálica tipo MCalso: cable armado MC
- Metal-clad cable: insulated conductors inside a metal armor, usually with a separate green grounding conductor. Common in commercial work.
- Neutral conductor Conductor neutroalso: neutro (neutral)
- The conductor connected to the neutral point of a system, meant to carry current under normal conditions. It is usually grounded and white or gray.
- NM cable Cable con forro no metálico tipo NMalso: cable Romex
- Nonmetallic-sheathed cable with insulated conductors and a bare grounding wire inside a plastic jacket, mainly for dwellings and other permitted buildings. Its ampacity is limited to the 60°C column.
- SE cable Cable de acometida tipo SE
- Service-entrance cable, used mainly for service-entrance conductors and, with conditions, for feeders and branch circuits.
- Termination temperature rating Temperatura nominal de las terminales
- The temperature limit of the lugs on breakers and equipment. Conductor ampacity is usually taken from the 60°C or 75°C column to match it, even for 90°C wire.
- THHN THHNalso: cable THHN
- A thermoplastic-insulated conductor with a nylon jacket, rated 90°C in dry locations. It is often dual-rated THHN/THWN-2.
- THWN-2 THWN-2
- A thermoplastic, heat- and moisture-resistant conductor with a nylon jacket, rated 90°C in both dry and wet locations.
- UF cable Cable tipo UFalso: cable subterráneo para alimentadores y circuitos derivados
- Underground feeder and branch-circuit cable that can be buried directly in the earth. Its ampacity is limited to the 60°C column.
- Ungrounded conductor Conductor no puesto a tierraalso: fase, vivo
- A circuit conductor that is not intentionally grounded, often called the hot or phase conductor.
- Voltage drop Caída de tensiónalso: caída de voltaje
- The voltage lost along a conductor because of its resistance. NEC informational notes suggest about 3% for a branch circuit or feeder and 5% total.
- XHHW-2 XHHW-2
- A conductor with cross-linked polyethylene insulation, rated 90°C in dry and wet locations. It is common for aluminum feeders.
Raceways and boxes
- Box fill Llenado de cajasalso: ocupación de cajas
- The calculation that checks a box is big enough for its conductors, devices, clamps and fittings, each counted as conductor volume allowances.
- Burial depth Profundidad de enterramientoalso: profundidad de cubierta
- The minimum cover over underground cables and raceways, which depends on the wiring method and location.
- Bushing Monitoralso: boquilla
- A fitting on the end of a conduit that protects conductor insulation from sharp edges. Insulated bushings are required for 4 AWG and larger conductors.
- Cable tray Charola portacablesalso: bandeja portacables
- An open support system of rails and rungs or a solid bottom for holding cables and raceways.
- Conduit Tubo conduitalso: tubería conduit
- A round raceway of metal or plastic that protects conductors pulled through it. In the field the word covers EMT, RMC, IMC, PVC and others.
- Conduit body Conduletalso: cuerpo de conduit
- A fitting such as an LB, LL, LR, T or C with a removable cover that gives access to conductors at a bend or joint.
- Conduit fill Ocupación del tubo conduitalso: llenado de tubería
- The share of a raceway's inside area that conductors may occupy: 53% for one conductor, 31% for two and 40% for three or more.
- Electrical metallic tubing (EMT) Tubo conduit metálico ligero tipo EMTalso: tubo de pared delgada
- Thin-wall, unthreaded steel tubing joined with setscrew or compression fittings. It is the most common raceway in commercial buildings.
- Electrical nonmetallic tubing (ENT) Tubo conduit no metálico tipo ENTalso: tubo corrugado
- A corrugated, pliable plastic raceway that can be bent by hand. Electricians often call the blue version smurf tube.
- Flexible metal conduit (FMC) Tubo conduit metálico flexible tipo FMCalso: tubo flexible (greenfield)
- Spiral interlocked metal conduit used for short flexible runs to motors and equipment. Trade name: greenfield.
- Handhole enclosure Registro
- An underground enclosure with an open or closed bottom, big enough to reach into but not to enter.
- Intermediate metal conduit (IMC) Tubo conduit metálico semipesado tipo IMCalso: tubo semipesado
- Threaded steel conduit with a wall thinner than RMC but thicker than EMT, permitted in the same places as RMC.
- Junction box Caja de empalmesalso: caja de conexiones
- A box where conductors are spliced, with a removable cover that must stay accessible.
- Liquidtight flexible metal conduit (LFMC) Tubo conduit metálico flexible hermético a los líquidos tipo LFMCalso: tubo flexible sellado (liquidtight)
- Flexible metal conduit with a liquidtight plastic jacket, used for wet or oily locations and equipment that vibrates.
- Nipple Niple
- A short piece of raceway, 24 inches or less, between boxes or enclosures. It may be filled to 60% and needs no ampacity adjustment.
- Outlet box Caja de salidaalso: chalupa
- A box at an outlet that holds a device or supports a luminaire. Its size must satisfy the box fill rules.
- Pull box Caja de pasoalso: caja de jalado
- A box placed in a raceway run to make pulling conductors easier. For 4 AWG and larger, its size is based on the raceway diameters entering it.
- PVC conduit Tubo conduit rígido de PVCalso: tubo PVC
- Rigid polyvinyl chloride conduit joined with solvent cement. It resists corrosion and needs expansion fittings where temperature changes a lot.
- Raceway Canalizaciónalso: tubería
- An enclosed channel made to hold wires, cables or busbars, such as conduit, tubing or wireway.
- Raceway bends Curvas en la canalizaciónalso: dobleces
- The total of all bends between pull points may not exceed 360 degrees. Each raceway article has the same limit.
- Rigid metal conduit (RMC) Tubo conduit metálico pesado tipo RMCalso: tubo de pared gruesa
- Heavy-wall threaded steel or aluminum conduit, permitted in almost all conditions, including severe physical damage.
- Volume allowance Volumen por conductor
- The cubic inches assigned to each conductor by size, for example 2.00 in³ for 14 AWG and 2.25 in³ for 12 AWG.
- Wireway Ducto metálico con tapaalso: canal (wireway)
- A sheet-metal trough with a hinged or removable cover, used to hold and lay in conductors.
Grounding and bonding
- Bonding Uniónalso: conexión equipotencial
- Connecting metal parts together so they are electrically continuous and at the same potential.
- Bonding jumper Puente de unión
- A reliable conductor that keeps electrical conductivity between metal parts that must be connected.
- Concrete-encased electrode Electrodo recubierto en concretoalso: electrodo Ufer
- At least 20 feet of rebar or bare copper in a footing or foundation that touches the earth. Its GEC never needs to be larger than 4 AWG copper.
- Effective ground-fault current path Trayectoria efectiva de la corriente de falla a tierra
- A low-impedance path built on purpose to carry fault current back to the source so the protective device opens quickly. The earth is never this path.
- Equipment grounding conductor (EGC) Conductor de puesta a tierra de equiposalso: cable de tierra
- The conductive path that connects metal parts of equipment to the grounded conductor at the source, so a ground fault trips the breaker. Its minimum size comes from the OCPD rating.
- Ground Tierraalso: tierra física
- The earth itself.
- Ground fault Falla a tierra
- An unintended connection between an ungrounded conductor and grounded metal, an equipment grounding conductor or the earth.
- Ground rod Varilla de tierraalso: varilla copperweld
- A driven rod electrode at least 8 feet long. A single rod needs a second electrode unless it measures 25 ohms or less to earth.
- Grounded Puesto a tierraalso: aterrizado
- Connected to the earth or to a conductive body that extends the earth connection.
- Grounded conductor Conductor puesto a tierraalso: neutro (cuando es el neutro)
- A system or circuit conductor that is intentionally grounded, usually the white neutral. It carries normal current, unlike the grounding conductor.
- Grounding conductor Conductor de puesta a tierraalso: tierra
- A general term for a conductor that connects equipment or a system to ground. Do not confuse it with the grounded conductor (neutral).
- Grounding electrode Electrodo de puesta a tierra
- A conductive object that makes direct contact with the earth, such as a ground rod, concrete-encased electrode or metal water pipe.
- Grounding electrode conductor (GEC) Conductor del electrodo de puesta a tierraalso: cable a la varilla
- The conductor that connects the system grounded conductor or equipment to a grounding electrode. It is sized from the largest service-entrance conductor.
- Grounding electrode system Sistema de electrodos de puesta a tierra
- All grounding electrodes present at a building, bonded together to form one system.
- Intersystem bonding termination Terminal de unión entre sistemas
- A device at the service that gives phone, cable TV and other communication systems a place to bond to the building's grounding system.
- Main bonding jumper Puente de unión principal
- The connection at the service between the grounded conductor and the equipment grounding conductors. It is the only neutral-to-ground bond in a building on a service.
- Metal underground water pipe Tubería metálica subterránea para agua
- Metal water pipe in contact with the earth for 10 feet or more. It counts as an electrode but must always be supplemented by another one.
- Separately derived system Sistema derivado separadoalso: sistema derivado por separado
- A power source, such as a transformer or some generators, with no direct connection to the supply circuit conductors other than through grounding and bonding.
- Supply-side bonding jumper Puente de unión del lado del suministroalso: puente de unión del lado fuente
- A bonding jumper on the line side of the service or a separately derived system's overcurrent device. It is sized from the ungrounded supply conductors.
- System bonding jumper Puente de unión del sistema
- The connection between the grounded conductor and the equipment grounding conductor at a separately derived system, such as a transformer.
Overcurrent protection
- Available fault current Corriente de falla disponiblealso: corriente de cortocircuito disponible
- The largest current that could flow at a point during a short circuit. Service equipment in other than dwellings must be marked with it.
- Circuit breaker Interruptor automáticoalso: breaker, pastilla
- A device that opens a circuit automatically on overcurrent and can be reset and used again. In Mexico it is often called pastilla termomagnética.
- Dual-element time-delay fuse Fusible de doble elementoalso: fusible de acción retardada
- A fuse that rides through short inrush currents such as motor starting but still opens fast on a short circuit.
- Fuse Fusible
- A device with a metal link that melts and opens the circuit on overcurrent. It must be replaced after it operates.
- Ground-fault protection of equipment (GFPE) Protección de equipos contra fallas a tierra
- Protection that opens all ungrounded conductors at a set ground-fault level to prevent equipment damage. It is required on certain large solidly grounded wye services.
- Instantaneous trip circuit breaker Interruptor automático de disparo instantáneoalso: breaker solo magnético
- A breaker with no intentional delay, used only as part of a listed motor controller combination.
- Interrupting rating Capacidad de interrupciónalso: capacidad interruptiva
- The highest current at rated voltage that a fuse or breaker can safely interrupt. It must be at least the available fault current.
- Inverse time circuit breaker Interruptor automático de tiempo inversoalso: termomagnético
- A breaker that trips faster as current rises. This is the ordinary thermal-magnetic breaker.
- Next higher standard rating Tamaño estándar inmediato superioralso: regla del siguiente tamaño
- When a conductor's ampacity does not match a standard size, the next higher OCPD is allowed up to 800 A, with conditions.
- Nontime-delay fuse Fusible sin retardoalso: fusible de acción rápida
- A fuse with no built-in delay, which opens quickly on any large overcurrent.
- Overcurrent Sobrecorriente
- Any current above the rating of equipment or the ampacity of a conductor. It can come from an overload, a short circuit or a ground fault.
- Overcurrent protective device (OCPD) Dispositivo de protección contra sobrecorrientealso: protección contra sobrecorriente
- A fuse or circuit breaker that opens a circuit on overcurrent to protect conductors and equipment.
- Overload Sobrecarga
- Running equipment or a conductor above its rating long enough to cause damaging heat. A short circuit or ground fault is not an overload.
- Short circuit Cortocircuitoalso: corto
- A low-resistance connection between conductors at different voltages, causing very high current.
- Short-circuit current rating (SCCR) Corriente nominal de cortocircuitoalso: valor nominal de corriente de cortocircuito
- The fault current an assembly such as a panel or control panel can withstand when protected as specified.
- Small conductor rule Regla de conductores pequeños
- Overcurrent limits for small copper conductors: 15 A for 14 AWG, 20 A for 12 AWG and 30 A for 10 AWG, unless another article allows more.
- Standard ampere ratings Capacidades nominales estándaralso: tamaños estándar de breakers y fusibles
- The list of standard fuse and breaker sizes, such as 15, 20, 25, 30, 35, 40, 45, 50, 60 and 70 A.
- Tap conductor Conductor de derivaciónalso: derivación (tap)
- A conductor protected at a higher rating than its ampacity, allowed only under the tap rules for length and termination.
Services and feeders
- Branch circuit Circuito derivado
- The conductors between the final overcurrent device and the outlets.
- Building disconnecting means Medio de desconexión del edificio
- The disconnect required at a separate building or structure supplied by a feeder or branch circuit.
- Drip loop Gaza de goteoalso: bucle de goteo
- A downward loop in service conductors below the service head so rainwater drips off instead of entering the raceway.
- Emergency disconnect Medio de desconexión de emergencia
- An outdoor, readily accessible disconnect for one- and two-family dwellings so first responders can shut off power.
- Feeder Alimentador
- The conductors between the service or another power source and the final branch-circuit overcurrent device.
- Individual branch circuit Circuito derivado individual
- A branch circuit that supplies only one piece of utilization equipment.
- Multiwire branch circuit Circuito derivado multiconductor
- A branch circuit with two or more ungrounded conductors sharing one neutral. Its breakers must open all ungrounded conductors together.
- Overhead service conductors Conductores aéreos de acometida
- Customer-side overhead conductors from the service point to the first connection with the service-entrance conductors.
- Service Acometidaalso: servicio eléctrico
- The conductors and equipment that deliver power from the serving utility to the premises wiring.
- Service clearances Distancias libres de la acometidaalso: alturas mínimas
- Minimum heights of overhead service conductors above roofs, driveways, sidewalks and streets.
- Service disconnecting means Medio de desconexión de la acometidaalso: interruptor principal
- The switch or breaker that disconnects all building conductors from the service. It must be readily accessible, outside or nearest the point where conductors enter.
- Service drop Acometida aéreaalso: bajada de acometida
- The overhead conductors between the utility's system and the service point.
- Service equipment Equipo de acometida
- The main breaker or switch and fuses at the end of the service conductors that serve as the main control and cutoff of the supply.
- Service head Mufaalso: capuchón de acometida
- The rain-resistant fitting at the top of a service raceway or cable where overhead conductors enter. Electricians call it the weatherhead.
- Service lateral Acometida subterránea
- The underground conductors between the utility's system and the service point.
- Service point Punto de acometida
- The point where the utility's wiring ends and the premises wiring begins. The utility usually decides where it is.
- Service-entrance conductors Conductores de entrada de acometida
- The service conductors between the end of the service drop, lateral or overhead conductors and the service equipment.
- Temporary wiring Instalación provisional
- Wiring for construction, remodeling, holiday lighting or emergencies, allowed for a limited time. Receptacles for workers need GFCI protection.
Motors and controls
- Adjustable-speed drive Variador de frecuenciaalso: variador de velocidad (VFD)
- Power electronics that change the frequency and voltage supplied to a motor to control its speed.
- Controller Controlador
- A device or group of devices that controls the electric power to the equipment it serves, such as a starter or switch for a motor.
- Disconnecting means Medio de desconexiónalso: desconectador
- A device or group of devices that can disconnect the conductors of a circuit from their source.
- Full-load current (FLC) Corriente a plena carga
- The motor current listed in NEC Tables 430.247 to 430.250 by horsepower and voltage. It is used to size conductors, OCPD and disconnects, not the nameplate value.
- Generator Generadoralso: planta de emergencia, planta de luz
- A machine that turns mechanical energy into electricity. Its output conductors are generally sized at 115% of nameplate current.
- Hermetic refrigerant motor-compressor Motocompresor hermético de refrigeración
- A compressor and motor sealed in the same housing, as in air conditioners and heat pumps.
- Horsepower Caballos de fuerza (hp)
- The output rating of a motor. One horsepower equals 746 watts of mechanical output.
- In sight from A la vista de
- Visible and no more than 50 feet away. A motor disconnect generally must be in sight from the motor and the controller.
- Locked-rotor current Corriente de rotor bloqueadoalso: corriente de arranque
- The current a motor draws at start or when stalled, often around six times its full-load current.
- Maximum overcurrent protection (MOCP) Protección máxima contra sobrecorriente
- The largest fuse or breaker allowed for A/C equipment, printed on its nameplate. Going above it violates the listing.
- Minimum circuit ampacity (MCA) Ampacidad mínima del circuito
- The conductor ampacity printed on A/C nameplates. Size the branch-circuit conductors from it.
- Motor branch-circuit conductors Conductores del circuito derivado del motor
- Conductors that supply a single continuous-duty motor must have an ampacity of at least 125% of its full-load current.
- Motor branch-circuit short-circuit and ground-fault protection Protección del circuito derivado del motor contra cortocircuito y falla a tierra
- The fuse or breaker that protects a motor circuit against shorts and ground faults. It is sized as a percentage of FLC from Table 430.52 and may be larger than the conductor ampacity.
- Motor feeder Alimentador de motores
- A feeder supplying several motors, sized at 125% of the largest motor's FLC plus the FLC of all the others plus other loads.
- Motor overload protection Protección contra sobrecarga del motoralso: relevador de sobrecarga (térmico)
- A device, often heaters or an electronic relay in the starter, that protects the motor and its conductors from overheating during running overloads.
- Motor starter Arrancadoralso: arrancador magnético
- A controller with a contactor and overload relay that starts and stops a motor.
- Nameplate current (FLA) Corriente de placa (FLA)also: corriente nominal de placa de datos
- The full-load amperes printed on the motor nameplate. It is used to size overload protection.
- Rated-load current (RLA) Corriente de carga nominal
- The current of a hermetic motor-compressor at rated load, as marked by the equipment maker.
- Service factor Factor de servicio
- A multiplier showing how much overload a motor can handle continuously. With a service factor of 1.15 or more, overloads may be sized at 125% of nameplate current.
- Temperature rise Aumento de temperaturaalso: elevación de temperatura
- How much hotter than ambient the motor runs at full load. A marked rise of 40°C or less allows overloads at 125% of nameplate current.
Transformers
- Buck-boost transformer Transformador reductor-elevadoralso: buck-boost
- A small transformer wired as an autotransformer to raise or lower voltage a few percent, such as 208 V to 230 V.
- kVA rating Capacidad en kVAalso: potencia nominal en kVA
- The apparent power a transformer can deliver. Full-load current is kVA × 1,000 ÷ voltage, also divided by 1.732 for three-phase.
- Percent impedance Impedancia porcentual (%Z)
- A nameplate value that tells how much a transformer limits fault current. Lower impedance means more available fault current.
- Primary winding Devanado primarioalso: primario
- The winding connected to the supply.
- Secondary winding Devanado secundarioalso: secundario
- The winding connected to the load.
- Step-down transformer Transformador reductor
- A transformer whose secondary voltage is lower than its primary voltage, such as 480 V to 208Y/120 V.
- Transformer Transformador
- A device with no moving parts that changes AC voltage up or down through magnetic coupling between windings.
- Transformer overcurrent protection Protección contra sobrecorriente del transformador
- Fuses or breakers sized as a percentage of the transformer's rated currents, on the primary alone or on both primary and secondary.
- Transformer secondary conductors Conductores del secundario del transformador
- Conductors from a transformer secondary, which may run limited distances to their overcurrent device under the secondary conductor rules.
- Turns ratio Relación de transformaciónalso: relación de vueltas
- The ratio of primary to secondary turns, which sets the voltage ratio. Current changes in the opposite direction.
Load calculations
- Clothes dryer Secadora de ropa
- An electric dryer is counted at 5,000 W or its nameplate rating, whichever is larger, with demand factors for five or more dryers.
- Commercial kitchen equipment Equipo de cocina comercial
- Cooking and other kitchen equipment in restaurants and similar places. Three or more units may take a demand factor, but never below the two largest loads.
- Continuous load Carga continua
- A load whose maximum current is expected to last 3 hours or more. Conductors and OCPD are generally sized at 125% of it.
- Counter-mounted cooking unit Parrilla eléctrica empotradaalso: estufa de empotrar (cooktop)
- A cooktop built into a counter. In load calculations it is treated with the range demand rules.
- Demand factor Factor de demanda
- The ratio of the maximum demand of a system to its total connected load, used because not everything runs at once.
- Dwelling unit Unidad de viviendaalso: unidad habitacional
- One or more rooms used as a home by one or more people, with permanent provisions for living, sleeping, cooking and sanitation.
- Fastened-in-place appliance Aparato fijo en su lugaralso: aparatos fijos
- An appliance such as a dishwasher, disposal or water heater that is attached in place. Four or more in a dwelling may take a 75% demand factor.
- General lighting load Carga de alumbrado general
- A load figured from floor area times a volt-ampere-per-square-foot value for the occupancy type, with demand factors applied.
- Household range Estufa eléctricaalso: cocina eléctrica
- A freestanding electric cooking appliance. Its load comes from the range demand table, often 8 kW for one range of 12 kW or less.
- Laundry branch circuit Circuito derivado para lavanderíaalso: circuito de la lavadora
- A 20 A circuit for the laundry receptacle in a dwelling, counted at 1,500 VA in the load calculation.
- Load calculation Cálculo de cargas
- The NEC method for finding the minimum size of a service, feeder or branch circuit from the connected loads and demand factors.
- Multifamily dwelling Vivienda multifamiliaralso: edificio de departamentos
- A building with three or more dwelling units.
- Neutral load Carga del neutroalso: desequilibrio máximo
- The maximum unbalanced load between the neutral and any ungrounded conductor. Some loads, such as ranges and dryers, may be reduced for the neutral.
- Noncoincident loads Cargas no coincidentes
- Loads that do not run at the same time, such as heating and air conditioning. Only the larger one is counted.
- Noncontinuous load Carga no continua
- A load that does not run at full current for 3 hours or more. It is counted at 100% when sizing conductors and OCPD.
- Optional method Método opcional
- A simpler dwelling calculation that takes most loads at a single demand percentage. Use it on the exam only when the question says so.
- Receptacle load Carga de receptáculosalso: carga de contactos
- In non-dwelling calculations, each single or multiple receptacle on one yoke counts 180 VA, and a demand factor applies above 10 kVA.
- Show window Aparadoralso: escaparate, vitrina
- A window used to display goods or advertising, usually open or partly open at the back. Its lighting load is figured per linear foot of window.
- Sign outlet Salida para letreroalso: salida para anuncio
- A commercial building with ground-floor pedestrian access needs an outlet for a sign, counted at 1,200 VA minimum in the load calculation.
- Small-appliance branch circuit Circuito derivado para pequeños aparatos
- A 20 A circuit for kitchen, dining and pantry receptacles in a dwelling. At least two are required, each counted at 1,500 VA in the load calculation.
- Standard method Método estándaralso: método general
- The step-by-step NEC load calculation with separate demand factors for lighting, appliances, cooking, dryers and HVAC.
- Unit load Carga unitariaalso: VA por pie cuadrado
- The VA per square foot assigned to each occupancy type for the general lighting calculation.
- Wall-mounted oven Horno de paredalso: horno empotrado
- An oven built into a wall. A cooktop and up to two ovens in the same room may be added together and treated as one range.
- Water heater Calentador de aguaalso: boiler
- A storage water heater of 120 gallons or less is treated as a continuous load, so its branch circuit is rated at least 125% of the nameplate.
Devices and equipment
- Appliance Aparatoalso: electrodoméstico
- Utilization equipment, usually not industrial, built in standard sizes for jobs such as cooking, laundry or cooling.
- Arc-fault circuit interrupter (AFCI) Interruptor de circuito por falla de arcoalso: ICFA, AFCI
- A device that detects the signature of a dangerous arc and opens the circuit to prevent fires.
- Bathroom Cuarto de bañoalso: baño
- An area with a basin plus a toilet, tub, shower, urinal or bidet. Bathroom receptacles need GFCI protection.
- Damp location Lugar húmedo
- A protected location exposed to some moisture, such as under a roofed open porch or in some basements.
- Device Dispositivo
- A part of the wiring system that carries or controls current but does not use it, such as a switch or receptacle.
- Enclosure Envolventealso: caja, gabinete
- The case or housing of equipment that keeps people from touching live parts and protects the equipment.
- Ground bar Barra de tierras
- The terminal bar, bonded to the enclosure, where equipment grounding conductors land.
- Ground-fault circuit interrupter (GFCI) Interruptor de circuito por falla a tierraalso: ICFT, GFCI
- A device that de-energizes a circuit when current leaking to ground goes over a small set value (about 4 to 6 mA), to protect people from shock.
- Kitchen Cocina
- An area with a sink and permanent provisions for preparing and cooking food. The definition matters for GFCI and receptacle rules.
- Load center Centro de cargaalso: panel residencial
- The trade name for a residential or light-commercial panelboard with plug-in breakers.
- Luminaire Luminariaalso: luminario
- A complete lighting unit with its light source, parts to position and protect it, and connection to power.
- Multioutlet assembly Ensamble de salidas múltiplesalso: multicontacto
- A surface or flush raceway with receptacles along it. In loads it counts 180 VA per 5 feet, or per foot where many appliances run at once.
- Neutral bar Barra de neutros
- The terminal bar where grounded (neutral) conductors land. It is bonded to the enclosure only at the service or a separately derived system.
- Outlet Salida
- A point in the wiring system where current is taken to supply utilization equipment, such as a receptacle or luminaire outlet.
- Panelboard Tablero de alumbrado y controlalso: panel, tablero
- A panel with buses and overcurrent devices for lighting, heat or power circuits, placed in a cabinet and reachable only from the front.
- Receptacle Receptáculoalso: contacto, tomacorriente
- A contact device installed at an outlet for connecting an attachment plug. A duplex receptacle is two receptacles on one yoke.
- Safety switch Interruptor de seguridadalso: desconectador de cuchillas
- An enclosed knife switch, fused or not, used as a disconnecting means for equipment or a service.
- Surge protective device (SPD) Dispositivo de protección contra sobretensiones (SPD)also: supresor de picos
- A device that limits transient voltage spikes by diverting surge current. Dwelling services now require one.
- Switchboard Tablero de distribuciónalso: switchboard
- A large freestanding panel or assembly of panels with switches, overcurrent devices and buses, usually reachable from the front and rear.
- Tamper-resistant receptacle Receptáculo a prueba de manipulaciones (TR)also: receptáculo resistente a la manipulación
- A receptacle with shutters that block objects from being pushed into one slot. Required in dwellings and many other places.
- Three-way switch Apagador de tres víasalso: apagador de escalera
- A switch used in pairs to control a light from two places.
- Transfer switch Interruptor de transferenciaalso: desconectador de transferencia, transferencia
- An automatic or manual switch that moves loads from one power source to another, such as from the utility to a generator, without connecting the two.
- Weather-resistant receptacle Receptáculo resistente a la intemperie (WR)
- A receptacle built to resist moisture and UV, required for 15 A and 20 A receptacles in damp and wet locations.
- Wet location Lugar mojado
- A location exposed to weather, saturated with water, or underground, including the inside of underground raceways.
- Yoke Yugoalso: soporte del dispositivo
- The metal mounting strap of a device. Each yoke counts as two conductors of the largest size connected to it in box fill.
Special occupancies
- Class I location Área Clase Ialso: gases y vapores inflamables
- A hazardous location where flammable gases, vapors or liquid-produced vapors may be present in ignitible amounts.
- Class II location Área Clase IIalso: polvos combustibles
- A hazardous location made dangerous by combustible dust, such as grain elevators.
- Conduit seal Selloalso: accesorio sellador
- A fitting filled with sealing compound that stops gases and flames from traveling through conduit in a Class I location.
- Division 1 División 1
- A hazardous location where the hazard is likely present during normal operation.
- Division 2 División 2
- A hazardous location where the hazard is present only under abnormal conditions, such as a leak or equipment failure.
- Electric vehicle supply equipment (EVSE) Equipo de suministro para vehículo eléctrico (EVSE)also: cargador de vehículo eléctrico
- The equipment that delivers power to an electric vehicle, commonly called the charger. EV charging loads are treated as continuous.
- Emergency system Sistema de emergencia
- A legally required system that supplies power for life safety, such as exit and egress lighting, within 10 seconds of losing normal power.
- Energy storage system (ESS) Sistema de almacenamiento de energíaalso: baterías
- Batteries or other equipment that store energy and supply it later, often paired with PV.
- Equipotential bonding Unión equipotencial
- Bonding pool steel, metal parts, deck and water together, usually with 8 AWG solid copper, so no dangerous voltage difference exists.
- Explosionproof equipment Equipo a prueba de explosión
- Equipment in an enclosure that can contain an internal explosion and cool escaping gases so the surrounding atmosphere does not ignite.
- Hazardous (classified) location Área peligrosa (clasificada)also: lugar peligroso
- A place where fire or explosion hazards exist from flammable gases, vapors, combustible dust or ignitible fibers.
- Information technology equipment room Sala de equipo de tecnología de la informaciónalso: cuarto de cómputo
- A room for computers and data equipment that may use special wiring under a raised floor and a remote disconnect.
- Inverter Inversor
- Equipment that changes DC from PV modules or batteries into AC.
- Legally required standby system Sistema de reserva legalmente requerido
- A standby system required by law for loads that could create hazards or hamper rescue if power is lost, restored within 60 seconds.
- Manufactured home Casa prefabricadaalso: vivienda manufacturada
- A factory-built dwelling transported in sections and set on site, built to the federal standard for manufactured housing.
- Marina Marinaalso: puerto deportivo
- A facility for mooring boats, with rules for shore power receptacles, ground-fault protection and wiring over water.
- Mobile home Casa móvilalso: tráiler
- A factory-built home on a permanent chassis that can be moved and is used as a dwelling with or without a permanent foundation.
- Motor fuel dispensing facility Gasolineraalso: estación de servicio
- A place where fuel is dispensed into vehicles. Areas around the dispensers and tanks are classified as hazardous.
- Optional standby system Sistema de reserva opcional
- A standby generator system the owner chooses to install, such as a home backup generator.
- Photovoltaic (PV) system Sistema solar fotovoltaicoalso: paneles solares
- A system of solar modules, wiring and inverters that turns sunlight into electricity.
- Rapid shutdown Apagado rápido
- A PV function that lowers the voltage of conductors on or in a building within seconds so firefighters can work safely.
- Recreational vehicle (RV) Vehículo de recreo (RV)also: vehículo recreativo, motorhome
- A vehicle-type unit used as temporary living quarters for camping or travel, such as a motor home or travel trailer.
- RV park Estacionamiento para vehículos de recreoalso: parque de RV
- A lot with RV sites. Article 551 sets the site receptacles (20, 30 and 50 A) and the demand factors for the park's service.
- Signs and outline lighting Letreros eléctricos e iluminación de contornosalso: anuncios luminosos
- Electric signs and lighting that outlines buildings, with rules for disconnects, branch circuits and listing.
- Spa or hot tub Spa o tina de hidromasajealso: jacuzzi
- A hydromassage pool for recreation that is not drained after each use.
- Special occupancies Ocupaciones especialesalso: ambientes especiales
- NEC Chapter 5 locations with extra rules, such as hazardous areas, health care, assembly, mobile homes, RVs and marinas.
- Swimming pool Albercaalso: piscina
- A permanently installed or storable pool. Article 680 covers its wiring, bonding, GFCI protection and clearances.
- Wet-niche luminaire Luminaria de nicho húmedo
- An underwater pool light installed in a forming shell, with water around it.
Safety, licensing and the exam
- Apprentice electrician Aprendiz de electricistaalso: aprendiz
- A registered learner who works under licensed electricians. Texas apprentices need no exam but renew yearly with 4 hours of CE or enrollment in an apprenticeship program.
- Approved Aprobado
- Acceptable to the authority having jurisdiction.
- Arc flash Relámpago de arcoalso: arco eléctrico
- A burst of heat and light from an electric arc through air. Equipment likely to be worked on while energized needs an arc-flash warning label.
- Authority having jurisdiction (AHJ) Autoridad competentealso: inspector
- The organization, office or person who enforces the code and approves equipment and installations, usually the electrical inspector.
- Calculations exam Examen de cálculos
- The separate calculations portion of the Texas journeyman and master exams. Each portion must be passed with 70%.
- Candidate Information Bulletin Boletín Informativo para Candidatos
- The PSI booklet that lists exam content, rules, fees, allowed references and how to schedule.
- Continuing education Educación continua
- Training required to renew a license. Most Texas electrician licenses need 4 hours per license term covering the NEC, state law and rules, and safety.
- Electrical contractor Contratista eléctrico
- A business licensed by TDLR to do electrical work for the public. It needs no exam but must have a master electrician of record and insurance.
- Exception Excepción
- A stated case where a rule does not apply or applies differently. On the Texas exam, do not use exceptions unless the question tells you to.
- Informational note Nota informativa
- Explanatory material in the NEC that is not an enforceable requirement.
- Journeyman electrician Electricista oficial
- A Texas license for electricians who have 8,000 hours of experience under a master electrician and pass the TDLR exam. A journeyman works under a master's supervision.
- Journeyman industrial electrician Oficial electricista industrial
- A Texas license limited to industrial sites such as plants, refineries, pipelines and oil and gas facilities.
- Listed Listadoalso: certificado
- Included in a list from a testing organization, such as UL, showing the product meets a standard for a stated use.
- Lockout/tagout Bloqueo y etiquetadoalso: candadeo
- Locking a disconnect open and tagging it so no one can re-energize the circuit while someone works on it.
- Maintenance electrician Electricista de mantenimiento
- A Texas license for maintaining and repairing existing electrical systems on premises the employer owns or manages.
- Mandatory rule Regla obligatoria
- A code requirement using the words shall or shall not.
- Master electrician Maestro electricistaalso: electricista maestro
- The top Texas electrician license. It requires holding a journeyman license for two years, 12,000 hours of experience and passing the master exam.
- National Electrical Code (NEC) Código Eléctrico Nacional (NEC)also: NFPA 70
- The model electrical installation code published by NFPA as NFPA 70. Texas has used the 2026 edition since September 1, 2026.
- NEC knowledge exam Examen de conocimientos del NEC
- The code-knowledge portion of the Texas journeyman and master exams, separate from the calculations portion.
- NFPA 70E NFPA 70Ealso: norma de seguridad eléctrica en el trabajo
- The standard for electrical safety in the workplace, covering shock and arc-flash protection and safe work practices.
- Open book exam Examen a libro abierto
- A test where you may use your own NEC. Texas allows a soft-bound 2026 NEC with highlighting, notes and publisher-made permanent tabs, but no homemade tabs.
- Personal protective equipment (PPE) Equipo de protección personal (EPP)
- Gear such as rated gloves, face shields and arc-rated clothing that protects workers from shock and arc flash.
- PSI PSIalso: empresa de exámenes PSI
- The testing company that gives the Texas electrician exams at its test centers. It offers the exams in English or Spanish at no extra cost.
- Qualified person Persona calificada
- Someone with the skills, knowledge and safety training to work on electrical equipment and recognize its hazards.
- Readily accessible Fácilmente accesiblealso: de fácil acceso
- Reachable quickly for operation or inspection without tools, ladders or moving obstacles.
- Residential wireman Instalador eléctrico residencialalso: electricista residencial
- A Texas license for wiring one- and multifamily dwellings up to four stories. It requires 4,000 hours or an approved program, plus the exam.
- TDLR TDLR (Departamento de Licencias y Regulación de Texas)
- The Texas Department of Licensing and Regulation, the state agency that licenses electricians and sets the exam rules.
- Working space Espacio de trabajo
- The clear space required in front of equipment that may be serviced while energized, at least 30 inches wide, with depth set by voltage.
No term matches that.
Spanish technical terms follow NOM-001-SEDE (Mexico's code, which uses the NEC article numbers) and US industry usage; job-site words are listed as "also". NEC references are there so you can open your own 2026 book.