Code library
The electrical code, section by section
What the National Electrical Code actually requires, section by section, written for homeowners, contractors and property managers, plus what it means on a real job. Search it, browse it, or ask a question.
Every section has a diagram, free to share with credit: see all 143 diagrams
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General rules and working space
- NEC 90.4Who enforces the code and can approve alternativesHomes and commercial
- NEC 110.3(B)Install equipment per its listing instructionsHomes and commercial
- NEC 110.12Professional and skillful installation workHomes and commercial
- NEC 110.13Mounting equipment and California's ballasted solar ruleHomes and commercialCalifornia rule
- NEC 110.14(D)Tightening terminals to the required torqueHomes and commercial
- NEC 110.16Arc-flash warning labels on commercial equipmentCommercial
- NEC 110.21(B)Requirements for field-applied warning labelsHomes and commercial
- NEC 110.24Available fault current label at commercial servicesCommercial
- NEC 110.26(A)Working space in front of electrical panelsHomes and commercial
- NEC 110.26(C)(3)Exit doors and panic hardware for large electrical roomsCommercial
- NEC 110.26(E)Dedicated space above and around electrical panelsHomes and commercial
Branch circuits, GFCI and AFCI
- NEC 200.6How neutral wires must be identifiedHomes and commercial
- NEC 200.7Using a white or gray wire as a hot conductorHomes and commercial
- NEC 210.4Multiwire branch circuits and shared neutralsHomes and commercial
- NEC 210.8(A)GFCI protection in homesHomes
- NEC 210.8(B)GFCI protection in commercial buildingsCommercial
- NEC 210.8(D)GFCI for dishwashers, ranges, dryers and other appliancesHomes and commercial
- NEC 210.8(F)GFCI for outdoor outlets at homes, including A/C unitsHomes
- NEC 210.11(C)Required small-appliance, laundry, bath and garage circuitsHomes
- NEC 210.12Arc-fault (AFCI) protection in homesHomes
- NEC 210.12(E)AFCI protection when remodeling existing circuitsHomes
- NEC 210.19Branch-circuit wire size and minimum ampacityHomes and commercial
- NEC 210.23What loads 10-, 15- and 20-amp circuits may serveHomes and commercial
- NEC 210.52(A)Wall receptacle spacing in homes (the 6-ft rule)Homes
- NEC 210.52(C)Kitchen countertop and island receptaclesHomes
- NEC 210.52(D)Bathroom receptacle near the sinkHomes
- NEC 210.52(E)Outdoor receptacles at homes, decks and balconiesHomes
- NEC 210.52(G)Garage, basement and accessory building receptaclesHomes
- NEC 210.63Service receptacle for HVAC and electrical equipmentHomes and commercial
- NEC 210.70Required lighting outlets and switches in homesHomes
Load calculations
- NEC 220.14Load values for receptacles and other outletsHomes and commercial
- NEC 220.42General lighting load for non-dwelling buildingsCommercial
- NEC 220.53Demand factor for four or more fixed appliancesHomes
- NEC 220.54Electric clothes dryer load (5,000 VA minimum)Homes
- NEC 220.55Electric range and cooktop load calculationsHomes
- NEC 220.82Optional load calculation for a single homeHomes
- NEC 220.83Adding new loads to an existing home's serviceHomes
- NEC 220.87Using actual demand data to size added loadHomes and commercial
Services, feeders and outbuildings
- NEC 215.2Feeder wire size and minimum ampacityHomes and commercial
- NEC 225.30One supply per outbuilding: garages, ADUs and shopsHomes and commercial
- NEC 225.31(B)Disconnect location for detached buildingsHomes and commercial
- NEC 230.24Overhead service wire clearances over roofs and yardsHomes and commercial
- NEC 230.42Sizing service-entrance conductorsHomes and commercial
- NEC 230.67Whole-house surge protection at the serviceHomes and commercial
- NEC 230.70Where the main service disconnect must goHomes and commercial
- NEC 230.71How many service disconnects are allowedHomes and commercial
- NEC 230.79Minimum service size, including 100 A for homesHomes and commercial
- NEC 230.85Outdoor emergency disconnect for homesHomes
- NEC 230.95Ground-fault protection on large commercial servicesCommercial
Overcurrent protection
- NEC 240.4(D)Breaker limits for small wires: 14, 12 and 10 AWGHomes and commercial
- NEC 240.6Standard breaker and fuse sizesHomes and commercial
- NEC 240.21(B)Feeder taps: the 10-foot and 25-foot rulesCommercial
- NEC 240.24Where breakers and fuses may be locatedHomes and commercial
- NEC 240.67Arc energy reduction for fuses of 1,200 A and upCommercial
- NEC 240.87Arc energy reduction for breakers of 1,200 A and upCommercial
Grounding and bonding
- NEC 250.24Grounding and bonding at the serviceHomes and commercial
- NEC 250.32Grounding at detached garages, ADUs and outbuildingsHomes and commercial
- NEC 250.50Bonding all grounding electrodes togetherHomes and commercial
- NEC 250.52What counts as a grounding electrodeHomes and commercial
- NEC 250.53Ground rod installation and the 25-ohm ruleHomes and commercial
- NEC 250.66Sizing the grounding electrode conductorHomes and commercial
- NEC 250.68Grounding electrode connections and the 5 ft ruleHomes and commercial
- NEC 250.94Bonding point for phone, cable TV and internet linesHomes and commercial
- NEC 250.104Bonding water pipes, gas pipes and structural steelHomes and commercial
- NEC 250.118What can serve as the equipment groundHomes and commercial
- NEC 250.122Sizing the equipment ground wireHomes and commercial
- NEC 250.130(C)Adding a ground to an old two-prong outletHomes
- NEC 250.142(B)No neutral-to-ground connection past the mainHomes and commercial
Wiring methods, conductors and boxes
- NEC 300.4Protecting cables from nails and screwsHomes and commercial
- NEC 300.5How deep to bury underground wiringHomes and commercial
- NEC 300.11Supporting wiring above suspended ceilingsHomes and commercial
- NEC 300.15When a junction box is requiredHomes and commercial
- NEC 310.12Sizing service wires for a house: the 83% ruleHomes
- NEC 310.15Derating wire for heat and crowded conduitsHomes and commercial
- NEC 310.16Wire ampacity table and the 60/75 °C terminal ruleHomes and commercial
- NEC 314.16Box fill: how many wires fit in a boxHomes and commercial
- NEC 314.20Setting boxes flush with the wall surfaceHomes and commercial
- NEC 314.27(C)Ceiling boxes for paddle fansHomes
- NEC 314.29Junction boxes must stay accessibleHomes and commercial
- NEC 334.10Where NM cable (Romex) is allowedHomes and commercial
- NEC 334.12Where NM cable (Romex) is not allowedHomes and commercial
- NEC 334.15Protecting exposed NM cableHomes
- NEC 334.30Stapling and supporting NM cableHomes
- NEC 334.80NM cable ampacity and bundlingHomes
- NEC 352.44Expansion fittings on PVC conduitHomes and commercial
- NEC 394.12Knob-and-tube wiring and insulationHomesCalifornia rule
Switches, receptacles, panels and lighting
- NEC 404.2(C)Neutral wire required at light switchesHomes and commercial
- NEC 404.4Switches in wet locations and near tubsHomes and commercial
- NEC 404.8Switch accessibility and mounting heightHomes and commercial
- NEC 404.9(B)Grounding switches and metal cover platesHomes and commercial
- NEC 406.4(D)Replacing receptacles: GFCI, AFCI and TR rulesHomes and commercial
- NEC 406.9Receptacles outdoors and near tubs and showersHomes and commercial
- NEC 406.12Tamper-resistant receptaclesHomes and commercial
- NEC 408.2California: reserved breaker spaces in new homesHomesCalifornia rule
- NEC 408.4Panel circuit directory and labelingHomes and commercial
- NEC 408.36Overcurrent protection for panelboardsHomes and commercial
- NEC 408.41One neutral per terminal in panelsHomes and commercial
- NEC 410.10(D)Light fixtures over tubs and showersHomes and commercial
- NEC 410.16Light fixtures in clothes closetsHomes
- NEC 410.71Disconnects for fluorescent and LED tube fixturesCommercial
- NEC 410.116Recessed lights and insulation (IC vs non-IC)Homes
Appliances, HVAC, motors and generators
- NEC 409.110Industrial control panel markings and SCCRCommercial
- NEC 422.3California: electric-ready water heater, cooktop, dryerHomesCalifornia rule
- NEC 422.5GFCI protection for appliancesHomes and commercial
- NEC 422.16Cords for dishwashers, disposals and range hoodsHomes
- NEC 422.31Disconnects for hardwired appliancesHomes and commercial
- NEC 430.32Overload protection for motorsCommercial
- NEC 430.102Motor disconnect locationHomes and commercial
- NEC 440.3California: heat-pump-ready circuit at gas furnacesHomesCalifornia rule
- NEC 440.14Air-conditioner disconnect locationHomes and commercial
- NEC 445.18Generator disconnect and emergency shutdownHomes and commercial
Special locations
EV charging, pools and solar
- NEC 625.1.1California EV-ready rules for new constructionHomes and commercialCalifornia rule
- NEC 625.40Dedicated circuits for EV chargersHomes
- NEC 625.42EV charger ratings and load managementHomes and commercial
- NEC 625.43Disconnects for large EV chargersHomes and commercial
- NEC 625.52Ventilation for indoor EV chargingHomes and commercialCalifornia rule
- NEC 625.54GFCI for EV charging receptaclesHomes and commercial
- NEC 680.21GFCI protection for pool pump motorsHomes
- NEC 680.22Pool area receptacles and lightingHomes
- NEC 680.26Equipotential bonding for poolsHomes
- NEC 680.44GFCI protection for spas and hot tubsHomes
- NEC 680.71Hydromassage bathtub circuits and GFCIHomes
- NEC 690.8Solar PV circuit current and wire sizingHomes and commercial
- NEC 690.12Solar rapid shutdownHomes and commercial
- NEC 690.13Solar PV system disconnectHomes and commercial
Backup power, solar interconnection and batteries
- NEC 700.12Emergency power sources and the 10-second ruleCommercial
- NEC 701.12Legally required standby power sourcesCommercial
- NEC 702.4Sizing whole-home generators and backup batteriesHomes
- NEC 702.5Transfer switches and interlocks for standby powerHomes
- NEC 705.11Supply-side (line-side tap) solar and battery connectionsHomes and commercial
- NEC 705.12The 120% rule for solar and battery breakersHomes and commercial
- NEC 705.13Energy management systems (formerly PCS) for solarHomes and commercial
- NEC 705.20Disconnects for solar and other power sourcesHomes and commercial
- NEC 706.10California battery-ready rules for new homesHomesCalifornia rule
- NEC 706.15Disconnects and emergency shutdown for battery systemsHomes and commercial
- NEC 710.15Off-grid (stand-alone) power systemsHomes and commercial
Low-voltage and fire alarm
Tables
California’s own rules
Where the 2025 California Electrical Code adds to or changes the national code.
- NEC 110.13Mounting equipment and California's ballasted solar ruleHomes and commercialCalifornia rule
- NEC 394.12Knob-and-tube wiring and insulationHomesCalifornia rule
- NEC 408.2California: reserved breaker spaces in new homesHomesCalifornia rule
- NEC 422.3California: electric-ready water heater, cooktop, dryerHomesCalifornia rule
- NEC 440.3California: heat-pump-ready circuit at gas furnacesHomesCalifornia rule
- NEC 625.1.1California EV-ready rules for new constructionHomes and commercialCalifornia rule
- NEC 625.52Ventilation for indoor EV chargingHomes and commercialCalifornia rule
- NEC 706.10California battery-ready rules for new homesHomesCalifornia rule
- NEC 760.1.1California fire alarm wiring and NFPA 72CommercialCalifornia rule
Federal OSHA electrical rules
29 CFR 1910 Subpart S (general industry) and 1926 Subpart K (construction), in full, with a one-line summary of each section.
San Clemente · South OC to North County San Diego
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