AL Electrician cheat sheet

NEC Chapters 1 through 4 apply generally; Chapters 5 through 7 supplement or modify them, and Chapter 8 is independent of Chapters 1 through 7.

A grounded conductor is intentionally connected to earth and carries current during normal operation; an equipment grounding conductor does not carry current except during a fault.

Continuous loads are calculated at 125 percent plus 100 percent of noncontinuous loads for branch-circuit, feeder, and service sizing.

NEC 110.26 requires working space at least 3 feet deep, 30 inches wide, and 6.5 feet high for equipment rated 600 volts or less, with depth increasing by voltage and condition.

NEC 110.14(C) limits conductor ampacity by termination temperature rating; 60°C is used for circuits 100 amperes or less unless the terminals are listed for 75°C.

Recommended voltage drop is a maximum of 3 percent on a branch circuit and 5 percent total for feeder plus branch circuit.

Tamper-resistant receptacles are required in dwelling units under NEC 406.12.

GFCI protection is required for personnel in specified locations under NEC 210.8, and AFCI protection is required for specified dwelling branch circuits under NEC 210.12.

Type NM cable is permitted in dry, protected locations but is restricted from wet or damp locations and from being embedded in masonry or concrete.

Type UF cable is listed for wet locations and direct burial and must be protected where exposed to physical damage.

EMT must be secured within 3 feet of boxes and supported at intervals not exceeding 10 feet under NEC 358.30.

Rigid metal conduit follows similar support rules: within 3 feet of boxes and at intervals not exceeding 10 feet.

PVC Schedule 40 support intervals vary by size: 3 feet for 1/2 through 1 inch, 5 feet for 1 1/4 through 2 inches, and longer intervals for larger sizes.

Raceway fill limits are 53 percent for one conductor, 31 percent for two conductors, and 40 percent for three or more conductors under NEC Chapter 9, Table 1.

Box fill is calculated with NEC Table 314.16(B); each equipment grounding conductor counts as one conductor, and each yoke or device counts as two conductors.

Type NM cable must be secured within 12 inches of a box and at intervals not exceeding 4.5 feet under NEC 334.30.

Parallel conductors must be 1/0 AWG or larger unless a specific exception in NEC 310.10(H) applies.

The equipment grounding conductor is sized from NEC Table 250.122 using the rating of the overcurrent device protecting the circuit.

The grounding electrode conductor is sized from NEC Table 250.66 based on the largest service or feeder conductor; 8 AWG copper is the minimum for service conductors 2 AWG copper or smaller.

A single rod, pipe, or plate grounding electrode requires a supplemental electrode under NEC 250.53.

Metal water piping systems must be bonded, and a bonding jumper is required around a water meter or other removable fitting.

The main bonding jumper connects the service neutral to the equipment grounding bus at the service equipment and must not be repeated downstream.

NEC 240.4(D) limits 14 AWG copper to 15 amperes, 12 AWG to 20 amperes, and 10 AWG to 30 amperes for small conductors.

Standard overcurrent device ratings include 15, 20, 25, 30, 35, 40, 45, 50, 60, 70, 80, 90, 100, 110, 125, 150, 175, 200, 225, 250, 300, and 400 amperes.

Ground-fault circuit interrupter protection protects people from shock, while arc-fault circuit interrupter protection detects hazardous arcing in branch circuits.

Service ground-fault protection is required for certain solidly grounded wye services rated 1000 amperes or more under NEC 230.95.

A one-family dwelling service disconnecting means must have a rating of at least 100 amperes under NEC 230.79(C).

Dwelling wall receptacles must be spaced so no point along the floor line is more than 6 feet from a receptacle, and wall spaces 2 feet or wider require an outlet.

Dwelling units require at least two 20-ampere small-appliance branch circuits for kitchen and dining receptacles.

A dwelling unit requires at least one 20-ampere laundry branch circuit and at least one 20-ampere bathroom receptacle branch circuit.

GFCI protection is required in dwelling bathrooms, kitchens, outdoors, garages, basements, crawl spaces, and other locations specified in NEC 210.8.

AFCI protection is required for branch circuits supplying outlets in dwelling living areas under NEC 210.12.

Overhead service conductors require 10 feet of clearance above finished grade, 12 feet over residential driveways, and 18 feet over public streets subject to truck traffic.

Feeder and service neutral loads are calculated under NEC 220.61, with demand factors applied where permitted.

Motor branch-circuit conductors are sized at 125 percent of motor full-load current from NEC Tables 430.248 through 430.250.

Motor overload protection is sized to the motor nameplate current and is separate from branch-circuit short-circuit and ground-fault protection.

Motor short-circuit and ground-fault protection is selected from NEC Table 430.52, with permitted increases where the standard rating does not allow starting.

A motor disconnecting means must be within sight of the motor and controller under NEC 430.102 unless a permitted exception applies.

Transformer primary overcurrent protection under NEC 450.3(B) is generally 125 percent of primary current for transformers over 9 amperes, 167 percent for 2 through 9 amperes, and 300 percent for less than 2 amperes.

Transformer secondary overcurrent protection is generally 125 percent of secondary current for transformers over 9 amperes and 167 percent for less than 9 amperes.

A separately derived system requires a system bonding jumper and grounding electrode conductor connection at the transformer or source.

Hazardous locations are classified by class and division or zone, and equipment must be listed and marked for the specific location.

Health care facilities require selected receptacles on the critical branch to be supplied by the essential electrical system.

Ohm’s law states V = I × R, and power formulas include P = V × I, P = I²R, and P = V²/R.

Balanced three-phase real power equals √3 times line-to-line voltage times line current times power factor.

NEC Chapter 9 permits 53 percent conduit fill for one conductor, 31 percent for two conductors, and 40 percent for three or more conductors.

Box fill volume allowances in NEC Table 314.16(B) are 2.0 cubic inches for 14 AWG, 2.25 for 12 AWG, 2.5 for 10 AWG, 3.0 for 8 AWG, and 5.0 for 6 AWG.

Each equipment grounding conductor counts as one conductor for box fill, each cable clamp counts as one, and each yoke or device counts as two conductors.

Ampacity adjustment for bundled conductors is 80 percent for 4 through 6 current-carrying conductors, 70 percent for 7 through 9, and 50 percent for 10 through 20.

Ambient temperature correction factors are applied to conductor ampacity using NEC Table 310.15(B)(1).

Single-phase voltage drop is calculated as VD = 2 × K × I × L ÷ circular mils; three-phase voltage drop uses √3 in place of 2.

In a balanced three-phase linear system, the neutral current is zero, but harmonic loads can produce neutral current.

A CAT III meter is rated for distribution-level circuits such as panelboards and feeders; CAT IV is for service entrance, and CAT II is for receptacle circuits.

Live-dead-live voltage verification checks the tester on a known live source, then the de-energized circuit, then the known source again.

Lockout/tagout isolates energy sources and requires verification of absence of voltage at the load side before work.

Insulation resistance is measured with a megohmmeter on de-energized conductors to detect moisture, damage, or deterioration.

A clamp meter measures current by sensing the magnetic field around one conductor; it must not encircle both supply and return conductors.

A continuity test confirms a low-resistance path and is performed on de-energized circuits.

Arc-rated PPE and approach boundaries are determined by incident energy and NFPA 70E requirements.

A GFCI tester can trip a GFCI receptacle but does not replace a voltage verification or live-dead-live test.

OSHA requires hazard assessment, training, and appropriate PPE for electrical work.

The Alabama Electrical Contractors Board licenses electrical contractors in Alabama and administers qualification, examination, and disciplinary requirements.

Local jurisdictions in Alabama may require separate permits, inspections, and local business licenses in addition to state licensing.

A project estimate includes direct labor, materials, equipment, subcontractors, overhead, profit, and contingency.

Labor units are expressed as hours per item, and productivity factors adjust for job conditions, weather, access, and crew efficiency.

Change orders should be written and signed before changed work is performed, documenting scope, price, and schedule impact.

Alabama mechanic’s lien law may allow a contractor to claim a lien for unpaid labor or materials, subject to required notices and deadlines.

Permit and inspection fees are project costs and should be confirmed with the authority having jurisdiction before bidding.

A construction contract should define scope, price, schedule, payment terms, warranties, and dispute resolution.

Project records should include contracts, permits, inspection results, change orders, payroll, and tax documents.