VA Electrician flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Continuous load definition

A load in which the maximum current is expected to continue for 3 hours or more. Branch-circuit and feeder overcurrent devices must be sized at 125 percent of this load.

Ohm's law and power

Voltage equals current multiplied by resistance, E = I × R. Power in a resistive circuit equals voltage times current, P = E × I, which is also I²R.

Dwelling receptacle spacing rule

In dwelling units, receptacles must be placed so no point along the floor line of a wall space is more than 6 feet from a receptacle, and wall spaces 2 feet or wider need one.

Working space in front of equipment

For equipment rated 600 volts or less, the clear workspace must be at least 3 feet deep, 30 inches wide, and 6 feet 6 inches high, and may not be used for storage.

Single-phase voltage drop formula

Voltage drop equals 2 × K × I × L divided by circular mils, where K is 12.9 for copper or 21.2 for aluminum, I is amperes, and L is one-way length in feet.

AFCI protection scope

Arc-fault circuit-interrupter protection is required on dwelling branch circuits supplying outlets in bedrooms, living rooms, dining rooms, kitchens, closets, hallways, laundry areas, and similar rooms.

NM cable support intervals

Nonmetallic-sheathed cable must be secured at intervals not exceeding 4½ feet and within 12 inches of every box or fitting that does not provide a cable clamp.

Box fill per 12 AWG conductor

Each 12 AWG conductor counts as 2.25 cubic inches of box volume, each 14 AWG counts 2.0 cubic inches, and each 10 AWG counts 2.5 cubic inches.

Grounding conductor box fill count

All equipment grounding conductors in a box together count as one conductor volume, while each device or yoke counts as two volumes based on the largest conductor connected.

Direct burial cover depth

Cables and conductors at 600 volts or less must be buried at least 24 inches deep, except 18 inches under one- and two-family driveways and 12 inches for GFCI-protected residential branch circuits.

EMT support requirements

Electrical metallic tubing must be fastened within 3 feet of each box or termination and supported at intervals not exceeding 10 feet along the run.

Raceway 40 percent fill rule

Where three or more conductors are installed in a raceway, their total cross-sectional area may not exceed 40 percent of the interior cross-sectional area of the raceway.

Motor branch conductor sizing

Motor branch-circuit conductors must have an ampacity of at least 125 percent of the motor full-load current taken from the NEC motor tables, unless the motor is marked otherwise.

Motor running overload protection

Overload protection guards the motor against overheating from overload currents and is separate from the short-circuit and ground-fault protection; it is sized from nameplate service factor or temperature rise.

Fixed space heating branch circuits

For fixed electric space-heating equipment, branch-circuit conductors and overcurrent devices must be sized at 125 percent of the total connected load.

Air-conditioning nameplate protection

For a hermetic refrigerant motor-compressor, the branch-circuit short-circuit and ground-fault protective device may not exceed the rating marked on the nameplate as maximum fuse or circuit breaker.

Switch mounting height

Switches and circuit breakers used as switches must be installed so the center of the grip is not more than 6 feet 7 inches above the floor or working platform.

Class I hazardous location

Class I locations are those in which flammable gases or vapors may be present in quantities sufficient to produce explosive or ignitable mixtures, covered by Article 501.

Division 1 versus Division 2

Division 1 covers conditions that exist during normal operation; Division 2 covers conditions that exist only under abnormal operation such as equipment failure or faulty operation.

Repair garage floor classification

In major repair garages, the space from the floor up to 18 inches above it is classified Class I, Division 2 because gasoline vapors are heavier than air.

Pool equipotential bonding grid

Article 680 requires a bonding grid connecting pool shells, reinforcing steel, metal fittings, and associated equipment to eliminate voltage gradients, typically using 8 AWG solid copper.

Hazardous location equipment marking

Equipment intended for hazardous locations must be marked with its class, division or zone, and gas or dust group so it matches the classification of the area.

Ground rod electrode

A rod or pipe grounding electrode must be at least 8 feet long and ½ inch in diameter, driven below permanent moisture level, and supplemented unless its resistance is 25 ohms or less.

Concrete-encased electrode

At least 20 feet of ½-inch or larger reinforcing steel, or 20 feet of bare 4 AWG copper, encased in at least 2 inches of concrete near the bottom of a footing.

Grounding electrode conductor sizing

Table 250.66 requires a 2 AWG copper grounding electrode conductor where the largest ungrounded service conductor is over 3/0 through 350 kcmil.

Equipment grounding conductor sizing

Table 250.122 requires 12 AWG copper for a 20-ampere device, 10 AWG for 60 amperes, 8 AWG for 100 amperes, and 6 AWG for 200 amperes.

Small conductor overcurrent limits

Unless specifically permitted, 14 AWG copper is limited to 15 amperes, 12 AWG copper to 20 amperes, and 10 AWG copper to 30 amperes.

Intersystem bonding termination

A visible and accessible intersystem bonding termination must be provided near the service equipment so communications, CATV, and radio systems can connect to the grounding electrode system.

Virginia electrician licensing authority

Electrician tradesman licenses in Virginia are issued by the Department of Professional and Occupational Regulation through the Board for Contractors, under Title 54.1 of the Code of Virginia.

Virginia electrician license levels

Virginia credentials electricians as apprentice, journeyman, and master; a separate electrical contractor license is required to contract with the public for electrical work.

Virginia excavation notice rule

Before excavating in Virginia, the excavator must notify the notification center at 811 at least 2 business days but not more than 10 business days before the planned start.

Virginia building code adoption

The Virginia Uniform Statewide Building Code adopts the National Electrical Code by reference, and local building officials enforce it through permits, inspections, and certificates of occupancy.