209 terms

Electrical glossary for the Minnesota exam

Plain definitions of the words the exam, the code book and the Laws and Rules Booklet use, from journeyworker and registered unlicensed electrician to feeder and bonding jumper. Where it helps, each term names the 2026 NEC article to open and links a calculation drill.

Licensing and the exam

Approved
Acceptable to the authority having jurisdiction.NEC Article 100
Arc flash
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.NEC 110.16
Authority having jurisdiction (AHJ)
The organization, office or person who enforces the code and approves equipment and installations, usually the electrical inspector.NEC Article 100
Board of Electricity
The Minnesota board that adopts the electrical code and licensing rules. Its quarterly meeting minutes report exam pass rates.
Continuing education
Training needed to renew a license. Minnesota journeyworkers and masters need 16 hours per renewal, at least 12 of them on the NEC.
DLI
The Minnesota Department of Labor and Industry. It licenses electricians, runs the exams at its St. Paul office and inspects electrical work except where a city or other political subdivision runs its own inspections.
Electrical contractor
A business licensed by DLI to do electrical work for others. It must designate a responsible master electrician, give a $25,000 bond and carry general liability insurance.
Electrical permit
A request for inspection, sent with the fees at or before the start of work that must be inspected. In Minnesota it goes to DLI or to the city that runs its own inspections. Permits with fees of $1,000 or less are void 12 months after filing.
Exception
A stated case where a rule does not apply or applies differently. Use an exception on the exam only when the facts in the question meet it.
Informational note
Explanatory material in the NEC that is not an enforceable requirement.
Journeyworker electrician
Minnesota's Class A journeyworker license. It takes 48 months of acceptable experience and a passing score on DLI's 80-question exam. A journeyworker does electrical work for a licensed contractor or an employer.
Laws and Rules Booklet
The booklet DLI hands out in the exam room: the Minnesota Electrical Act and Minnesota Rules chapters 3800 and 3801.
Listed
Included in a list from a testing organization, such as UL, showing the product meets a standard for a stated use.NEC Article 100
Lockout/tagout
Locking a disconnect open and tagging it so no one can re-energize the circuit while someone works on it.
Maintenance electrician
A Minnesota license to maintain and repair electrical wiring and equipment while working for a contractor, or full time for one employer on property it owns or leases. It needs 48 months of experience; its exam has 70 questions.
Mandatory rule
A code requirement using the words shall or shall not.
Master electrician
Minnesota's Class A master license. You qualify for the exam with a four-year electrical degree, one year as a licensed journeyworker, or five years of planning, laying out, supervising and installing. A contractor names a master as its responsible licensed individual.
National Electrical Code (NEC)
The model electrical installation code published by NFPA as NFPA 70. Minnesota adopted the 2026 edition without amendments; it took effect Aug. 17, 2026.
NFPA 70E
The standard for electrical safety in the workplace, covering shock and arc-flash protection and safe work practices.
Open book exam
A test where reference books are allowed. Minnesota provides a soft-cover 2026 NEC with no tabs, the Laws and Rules Booklet and a calculator. Candidates bring nothing.
Personal protective equipment (PPE)
Gear such as rated gloves, face shields and arc-rated clothing that protects workers from shock and arc flash.
Power limited technician
A Minnesota license for technology circuits and systems, the power-limited work the Electrical Act defines. It needs 36 months of experience or a four-year electrical degree, and its exam has 80 questions.
Qualified person
Someone with the skills, knowledge and safety training to work on electrical equipment and recognize its hazards.NEC Article 100
Readily accessible
Reachable quickly for operation or inspection without tools, ladders or moving obstacles.NEC Article 100
Registered unlicensed electrician
A person registered with DLI to do electrical work before being licensed. The work must be directly supervised by a licensed journeyworker or master of the same employer, and one licensed electrician may supervise no more than two.
Responsible licensed individual
The master electrician or power limited technician a contractor designates as responsible for its license. The rules require 15 days' notice before that person resigns the role and a replacement within 30 days.
Untabbed code book
The exam copy of the NEC in Minnesota: soft cover, with no tabs or other aids. Finding an article through the table of contents and the index is a skill to practice.
Working space
The clear space required in front of equipment that may be serviced while energized, at least 30 inches wide, with depth set by voltage.NEC 110.26

Theory

Alternating current (AC)
Current that reverses direction many times a second. In the United States it alternates at 60 hertz.
Current
The flow of electric charge through a conductor, measured in amperes (A). Formulas write it as I.Practice →
Delta connection
A three-phase connection with the windings joined end to end in a closed loop. Line voltage equals winding voltage.Practice →
Direct current (DC)
Current that flows in one direction only, as from a battery or a PV module.
Efficiency
Output power divided by input power, as a percentage. A motor that is 90% efficient turns 10% of its input into heat.Practice →
Harmonics
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.
Impedance
The total opposition to alternating current, combining resistance and reactance, measured in ohms (Z).
Nominal voltage
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.NEC Article 100
Ohm's law
The rule that voltage equals current times resistance (E = I × R). Rearranged, it finds any one value from the other two.Practice →
Parallel circuit
A circuit with several branches across the same voltage. Total resistance is lower than the smallest branch resistance.Practice →
Power
The rate at which electrical energy is used or delivered, measured in watts. In a resistive circuit, P = E × I.Practice →
Power factor
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.Practice →
Resistance
Opposition to current flow in a material, measured in ohms. Longer and smaller conductors have more resistance.Practice →
Series circuit
A circuit with only one path, so the same current flows through every part. Total resistance is the sum of all resistances.Practice →
Three-phase
A system with three voltages 120 degrees apart. Power formulas for it include the square root of 3 (1.732).Practice →
True power
The power that does actual work or makes heat, measured in watts. It equals apparent power times power factor.Practice →
Volt-ampere (VA)
The unit of apparent power, volts times amperes. Load calculations are done in VA, and transformers are rated in kVA.Practice →
Voltage
The electrical pressure that pushes current through a circuit, measured in volts (V). Formulas write it as E or V.Practice →
Voltage to ground
For a grounded system, the highest voltage between a given conductor and the grounded point or conductor of the circuit.NEC Article 100
Wye connection
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.Practice →

Conductors

AC cable
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
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.Practice →
American Wire Gauge (AWG)
The US system of wire sizes. Smaller numbers are larger wires, and sizes above 4/0 AWG are given in kcmil.NEC Table 310.16Practice →
Ampacity
The most current a conductor can carry continuously under its conditions of use without going over its temperature rating.NEC Article 100Practice →
Circular mil
The area of a circle one mil (0.001 inch) across. Conductor areas in circular mils are used in voltage drop formulas.NEC Chapter 9, Table 8Practice →
Conductor color code
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
A conductor counted for adjustment factors. Equipment grounding conductors never count, and a neutral counts only in certain cases.Practice →
Flexible cord
A flexible cable for connecting portable equipment and appliances. It cannot be used as a substitute for permanent wiring.NEC Article 400
Insulation
The nonconducting layer around a conductor. Its letter type tells the temperature rating and where the wire may be used.NEC Article 310
kcmil
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.NEC Table 310.16Practice →
MC cable
Metal-clad cable: insulated conductors inside a metal armor, usually with a separate green grounding conductor. Common in commercial work.NEC Article 330
Neutral conductor
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.NEC Article 100Practice →
SE cable
Service-entrance cable, used mainly for service-entrance conductors and, with conditions, for feeders and branch circuits.NEC Article 338
Ungrounded conductor
A circuit conductor that is not intentionally grounded, often called the hot or phase conductor.NEC Article 100

Raceways and boxes

Box fill
The calculation that checks a box is big enough for its conductors, devices, clamps and fittings, each counted as conductor volume allowances.Practice →
Burial depth
The minimum cover over underground cables and raceways, which depends on the wiring method and location.NEC Article 300
Cable tray
An open support system of rails and rungs or a solid bottom for holding cables and raceways.NEC Article 392
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.Practice →
Conduit body
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.NEC Article 100Practice →
Electrical metallic tubing (EMT)
Thin-wall, unthreaded steel tubing joined with setscrew or compression fittings. It is the most common raceway in commercial buildings.NEC Article 358Practice →
Electrical nonmetallic tubing (ENT)
A corrugated, pliable plastic raceway that can be bent by hand. Electricians often call the blue version smurf tube.Practice →
Flexible metal conduit (FMC)
Spiral interlocked metal conduit used for short flexible runs to motors and equipment. Trade name: greenfield.Practice →
Handhole enclosure
An underground enclosure with an open or closed bottom, big enough to reach into but not to enter.NEC Article 100
Intermediate metal conduit (IMC)
Threaded steel conduit with a wall thinner than RMC but thicker than EMT, permitted in the same places as RMC.Practice →
Junction box
A box where conductors are spliced, with a removable cover that must stay accessible.NEC Article 314Practice →
Liquidtight flexible metal conduit (LFMC)
Flexible metal conduit with a liquidtight plastic jacket, used for wet or oily locations and equipment that vibrates.NEC Article 350Practice →
Outlet box
A box at an outlet that holds a device or supports a luminaire. Its size must satisfy the box fill rules.NEC Article 314Practice →
PVC conduit
Rigid polyvinyl chloride conduit joined with solvent cement. It resists corrosion and needs expansion fittings where temperature changes a lot.NEC Article 352Practice →
Raceway
An enclosed channel made to hold wires, cables or busbars, such as conduit, tubing or wireway.NEC Article 100Practice →
Rigid metal conduit (RMC)
Heavy-wall threaded steel or aluminum conduit, permitted in almost all conditions, including severe physical damage.Practice →
Wireway
A sheet-metal trough with a hinged or removable cover, used to hold and lay in conductors.

Grounding and bonding

Bonding
Connecting metal parts together so they are electrically continuous and at the same potential.NEC Article 100
Bonding jumper
A reliable conductor that keeps electrical conductivity between metal parts that must be connected.
Effective ground-fault current path
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)
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.NEC 250.122Practice →
Ground
The earth itself.NEC Article 100
Ground fault
An unintended connection between an ungrounded conductor and grounded metal, an equipment grounding conductor or the earth.NEC Article 100
Grounded
Connected to the earth or to a conductive body that extends the earth connection.NEC Article 100
Grounded conductor
A system or circuit conductor that is intentionally grounded, usually the white neutral. It carries normal current, unlike the grounding conductor.NEC Article 100Practice →
Grounding conductor
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
A conductive object that makes direct contact with the earth, such as a ground rod, concrete-encased electrode or metal water pipe.NEC 250.52Practice →
Grounding electrode conductor (GEC)
The conductor that connects the system grounded conductor or equipment to a grounding electrode. It is sized from the largest service-entrance conductor.Practice →
Grounding electrode system
All grounding electrodes present at a building, bonded together to form one system.
Intersystem bonding termination
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
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.
Separately derived system
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.NEC 250.30
Supply-side bonding jumper
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
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
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
A device that opens a circuit automatically on overcurrent and can be reset and used again. In Mexico it is often called pastilla termomagnética.NEC Article 100Practice →
Dual-element time-delay fuse
A fuse that rides through short inrush currents such as motor starting but still opens fast on a short circuit.Practice →
Fuse
A device with a metal link that melts and opens the circuit on overcurrent. It must be replaced after it operates.NEC Article 100Practice →
Ground-fault protection of equipment (GFPE)
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.NEC 230.95
Instantaneous trip circuit breaker
A breaker with no intentional delay, used only as part of a listed motor controller combination.Practice →
Interrupting rating
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
A breaker that trips faster as current rises. This is the ordinary thermal-magnetic breaker.Practice →
Nontime-delay fuse
A fuse with no built-in delay, which opens quickly on any large overcurrent.Practice →
Overcurrent
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.NEC Article 100Practice →
Overcurrent protective device (OCPD)
A fuse or circuit breaker that opens a circuit on overcurrent to protect conductors and equipment.NEC Article 240Practice →
Overload
Running equipment or a conductor above its rating long enough to cause damaging heat. A short circuit or ground fault is not an overload.NEC Article 100Practice →
Short circuit
A low-resistance connection between conductors at different voltages, causing very high current.
Short-circuit current rating (SCCR)
The fault current an assembly such as a panel or control panel can withstand when protected as specified.
Tap conductor
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
The conductors between the final overcurrent device and the outlets.NEC Article 100Practice →
Building disconnecting means
The disconnect required at a separate building or structure supplied by a feeder or branch circuit.NEC 225.31
Drip loop
A downward loop in service conductors below the service head so rainwater drips off instead of entering the raceway.
Emergency disconnect
An outdoor, readily accessible disconnect for one- and two-family dwellings so first responders can shut off power.
Feeder
The conductors between the service or another power source and the final branch-circuit overcurrent device.NEC Article 100Practice →
Individual branch circuit
A branch circuit that supplies only one piece of utilization equipment.NEC Article 100
Multiwire branch circuit
A branch circuit with two or more ungrounded conductors sharing one neutral. Its breakers must open all ungrounded conductors together.NEC 210.4Practice →
Overhead service conductors
Customer-side overhead conductors from the service point to the first connection with the service-entrance conductors.NEC Article 100
Service
The conductors and equipment that deliver power from the serving utility to the premises wiring.NEC Article 100Practice →
Service clearances
Minimum heights of overhead service conductors above roofs, driveways, sidewalks and streets.NEC 230.24
Service disconnecting means
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
The overhead conductors between the utility's system and the service point.NEC Article 100
Service equipment
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.NEC Article 100
Service head
The rain-resistant fitting at the top of a service raceway or cable where overhead conductors enter. Electricians call it the weatherhead.
Service lateral
The underground conductors between the utility's system and the service point.NEC Article 100
Service point
The point where the utility's wiring ends and the premises wiring begins. The utility usually decides where it is.NEC Article 100
Service-entrance conductors
The service conductors between the end of the service drop, lateral or overhead conductors and the service equipment.NEC Article 100Practice →
Temporary wiring
Wiring for construction, remodeling, holiday lighting or emergencies, allowed for a limited time. Receptacles for workers need GFCI protection.NEC Article 590

Motors and controls

Adjustable-speed drive
Power electronics that change the frequency and voltage supplied to a motor to control its speed.NEC Article 100
Controller
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.NEC Article 100
Disconnecting means
A device or group of devices that can disconnect the conductors of a circuit from their source.NEC Article 100
Hermetic refrigerant motor-compressor
A compressor and motor sealed in the same housing, as in air conditioners and heat pumps.NEC Article 440
Horsepower
The output rating of a motor. One horsepower equals 746 watts of mechanical output.NEC Article 430Practice →
Locked-rotor current
The current a motor draws at start or when stalled, often around six times its full-load current.
Maximum overcurrent protection (MOCP)
The largest fuse or breaker allowed for A/C equipment, printed on its nameplate. Going above it violates the listing.NEC Article 440
Minimum circuit ampacity (MCA)
The conductor ampacity printed on A/C nameplates. Size the branch-circuit conductors from it.NEC Article 440
Motor overload protection
A device, often heaters or an electronic relay in the starter, that protects the motor and its conductors from overheating during running overloads.NEC 430.32Practice →
Motor starter
A controller with a contactor and overload relay that starts and stops a motor.NEC Article 430
Nameplate current (FLA)
The full-load amperes printed on the motor nameplate. It is used to size overload protection.NEC 430.6(A)(2)Practice →
Rated-load current (RLA)
The current of a hermetic motor-compressor at rated load, as marked by the equipment maker.NEC Article 440

Transformers

Buck-boost transformer
A small transformer wired as an autotransformer to raise or lower voltage a few percent, such as 208 V to 230 V.
kVA rating
The apparent power a transformer can deliver. Full-load current is kVA × 1,000 ÷ voltage, also divided by 1.732 for three-phase.Practice →
Percent impedance
A nameplate value that tells how much a transformer limits fault current. Lower impedance means more available fault current.
Primary winding
The winding connected to the supply.Practice →
Secondary winding
The winding connected to the load.Practice →
Step-down transformer
A transformer whose secondary voltage is lower than its primary voltage, such as 480 V to 208Y/120 V.Practice →
Transformer
A device with no moving parts that changes AC voltage up or down through magnetic coupling between windings.NEC Article 450Practice →
Transformer overcurrent protection
Fuses or breakers sized as a percentage of the transformer's rated currents, on the primary alone or on both primary and secondary.Practice →
Transformer secondary conductors
Conductors from a transformer secondary, which may run limited distances to their overcurrent device under the secondary conductor rules.NEC 240.21(C)Practice →
Turns ratio
The ratio of primary to secondary turns, which sets the voltage ratio. Current changes in the opposite direction.Practice →

Load calculations

Commercial kitchen equipment
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.NEC Article 120Practice →
Counter-mounted cooking unit
A cooktop built into a counter. In load calculations it is treated with the range demand rules.NEC Article 120
Demand factor
The ratio of the maximum demand of a system to its total connected load, used because not everything runs at once.NEC Article 100Practice →
Dwelling unit
One or more rooms used as a home by one or more people, with permanent provisions for living, sleeping, cooking and sanitation.NEC Article 100Practice →
General lighting load
A load figured from floor area times a volt-ampere-per-square-foot value for the occupancy type, with demand factors applied.NEC Article 120Practice →
Load calculation
The NEC method for finding the minimum size of a service, feeder or branch circuit from the connected loads and demand factors.NEC Article 120Practice →
Multifamily dwelling
A building with three or more dwelling units.NEC Article 100Practice →
Neutral load
The maximum unbalanced load between the neutral and any ungrounded conductor. Some loads, such as ranges and dryers, may be reduced for the neutral.NEC Article 120Practice →
Noncoincident loads
Loads that do not run at the same time, such as heating and air conditioning. Only the larger one is counted.NEC Article 120Practice →
Optional method
A simpler dwelling calculation that takes most loads at a single demand percentage. Use it on the exam only when the question says so.NEC Article 120Practice →
Show window
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.NEC Article 100Practice →
Standard method
The step-by-step NEC load calculation with separate demand factors for lighting, appliances, cooking, dryers and HVAC.NEC Article 120Practice →
Unit load
The VA per square foot assigned to each occupancy type for the general lighting calculation.NEC Article 120Practice →
Wall-mounted oven
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.NEC Article 120

Devices and equipment

Appliance
Utilization equipment, usually not industrial, built in standard sizes for jobs such as cooking, laundry or cooling.NEC Article 100Practice →
Arc-fault circuit interrupter (AFCI)
A device that detects the signature of a dangerous arc and opens the circuit to prevent fires.NEC 210.12
Bathroom
An area with a basin plus a toilet, tub, shower, urinal or bidet. Bathroom receptacles need GFCI protection.NEC Article 100
Damp location
A protected location exposed to some moisture, such as under a roofed open porch or in some basements.NEC Article 100
Device
A part of the wiring system that carries or controls current but does not use it, such as a switch or receptacle.NEC Article 100
Enclosure
The case or housing of equipment that keeps people from touching live parts and protects the equipment.NEC Article 100
Ground bar
The terminal bar, bonded to the enclosure, where equipment grounding conductors land.Practice →
Kitchen
An area with a sink and permanent provisions for preparing and cooking food. The definition matters for GFCI and receptacle rules.NEC Article 100
Load center
The trade name for a residential or light-commercial panelboard with plug-in breakers.NEC Article 408
Luminaire
A complete lighting unit with its light source, parts to position and protect it, and connection to power.NEC Article 100
Neutral bar
The terminal bar where grounded (neutral) conductors land. It is bonded to the enclosure only at the service or a separately derived system.Practice →
Outlet
A point in the wiring system where current is taken to supply utilization equipment, such as a receptacle or luminaire outlet.NEC Article 100
Panelboard
A panel with buses and overcurrent devices for lighting, heat or power circuits, placed in a cabinet and reachable only from the front.NEC Article 408
Receptacle
A contact device installed at an outlet for connecting an attachment plug. A duplex receptacle is two receptacles on one yoke.NEC Article 100Practice →
Safety switch
An enclosed knife switch, fused or not, used as a disconnecting means for equipment or a service.
Surge protective device (SPD)
A device that limits transient voltage spikes by diverting surge current. Dwelling services now require one.
Switchboard
A large freestanding panel or assembly of panels with switches, overcurrent devices and buses, usually reachable from the front and rear.NEC Article 408
Tamper-resistant receptacle
A receptacle with shutters that block objects from being pushed into one slot. Required in dwellings and many other places.NEC Article 406
Three-way switch
A switch used in pairs to control a light from two places.NEC Article 404
Transfer switch
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.NEC Article 100
Wet location
A location exposed to weather, saturated with water, or underground, including the inside of underground raceways.NEC Article 100
Yoke
The metal mounting strap of a device. Each yoke counts as two conductors of the largest size connected to it in box fill.NEC 314.16(B)Practice →

Special occupancies

Class I location
A hazardous location where flammable gases, vapors or liquid-produced vapors may be present in ignitible amounts.
Class II location
A hazardous location made dangerous by combustible dust, such as grain elevators.
Conduit seal
A fitting filled with sealing compound that stops gases and flames from traveling through conduit in a Class I location.
Division 1
A hazardous location where the hazard is likely present during normal operation.
Division 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)
The equipment that delivers power to an electric vehicle, commonly called the charger. EV charging loads are treated as continuous.NEC Article 625
Energy storage system (ESS)
Batteries or other equipment that store energy and supply it later, often paired with PV.NEC Article 706
Explosionproof equipment
Equipment in an enclosure that can contain an internal explosion and cool escaping gases so the surrounding atmosphere does not ignite.NEC Article 100
Hazardous (classified) location
A place where fire or explosion hazards exist from flammable gases, vapors, combustible dust or ignitible fibers.NEC Article 500
Information technology equipment room
A room for computers and data equipment that may use special wiring under a raised floor and a remote disconnect.NEC Article 645
Inverter
Equipment that changes DC from PV modules or batteries into AC.NEC Article 690
Manufactured home
A factory-built dwelling transported in sections and set on site, built to the federal standard for manufactured housing.NEC Article 550
Marina
A facility for mooring boats, with rules for shore power receptacles, ground-fault protection and wiring over water.NEC Article 555
Mobile home
A factory-built home on a permanent chassis that can be moved and is used as a dwelling with or without a permanent foundation.NEC Article 550
Motor fuel dispensing facility
A place where fuel is dispensed into vehicles. Areas around the dispensers and tanks are classified as hazardous.NEC Article 514
Optional standby system
A standby generator system the owner chooses to install, such as a home backup generator.
Photovoltaic (PV) system
A system of solar modules, wiring and inverters that turns sunlight into electricity.NEC Article 690
Rapid shutdown
A PV function that lowers the voltage of conductors on or in a building within seconds so firefighters can work safely.NEC 690.12
Recreational vehicle (RV)
A vehicle-type unit used as temporary living quarters for camping or travel, such as a motor home or travel trailer.NEC Article 551
Signs and outline lighting
Electric signs and lighting that outlines buildings, with rules for disconnects, branch circuits and listing.NEC Article 600
Spa or hot tub
A hydromassage pool for recreation that is not drained after each use.NEC Article 680
Wet-niche luminaire
An underwater pool light installed in a forming shell, with water around it.

NEC references are there so you can find the rule in the code book. Licensing terms follow Minnesota Statutes 326B and Minnesota Rules 3800. We never print NEC text or tables.