Which states are on NEC 2026?
NEC 2026 is current in nine jurisdictions: Arkansas, Colorado, Maine, Massachusetts, Minnesota, North Dakota, Oregon, Texas and Wyoming. Each state's page gives the date it took effect and names its primary source.
Which states are still on NEC 2020 or older?
NEC 2020 is the current statewide edition in Alabama, Alaska, Connecticut, Florida, Louisiana, New Mexico, North Carolina, Pennsylvania, South Carolina, Virginia and West Virginia. NEC 2017 is the current statewide edition in Tennessee. NEC 2014 is the current statewide edition in the District of Columbia. NEC 2008 is the current statewide edition in Indiana. The oldest edition still current statewide is NEC 2008. Where cities and counties adopt their own, the app cites NEC 2020 for Hawaii, Illinois, Maryland and Mississippi. Where cities and counties adopt their own, the app cites NEC 2017 for Kansas.
Which states have no statewide NEC adoption?
Arizona, Hawaii, Illinois, Kansas, Maryland, Mississippi, Missouri and Nevada have no statewide NEC adoption: cities and counties adopt their own edition, so the edition depends on where the job is. Check with the city or county building department.
How often does the NEC change?
NFPA publishes a new edition of the National Electrical Code every three years; the newest is NEC 2026. Each state adopts a new edition on its own schedule, often with amendments, and some stay several editions behind.
What changed in NEC 2026?
Of the 118 key sections in the app's code library, 67 changed. Article 220's load calculations became Article 120, the dwelling lighting load dropped from 3 to 2 VA per square foot, and GFCI protection for dwelling outdoor outlets now reaches 60 amperes.
What is the maximum voltage drop allowed by the NEC?
The NEC recommends, in informational notes rather than requirements, that voltage drop stay at or below 3% on a branch circuit or a feeder and 5% for the two combined (NEC 210.19 and 215.2). Voltage drop is 2 × K × I × L ÷ circular mils on a single-phase circuit and 1.732 × K × I × L ÷ circular mils on a three-phase circuit, with K = 12.9 for copper and 21.2 for aluminum.
How do you calculate box fill?
Add up the volume each item takes in cubic inches and compare it with the box's volume (NEC 314.16). Each conductor counts its size's allowance: 2 in³ for 14 AWG, 2.25 for 12 AWG, 2.5 for 10 AWG. A device yoke counts two of the largest conductor connected to it; all equipment grounding conductors together count one; internal clamps count one.
What is the maximum conduit fill?
Conductors may fill 53% of a conduit's internal area when there is one, 31% when there are two, and 40% when there are three or more (NEC Chapter 9, Table 1). Add the conductors' areas from Chapter 9, Table 5 and compare the total with that percentage of the conduit's area from Chapter 9, Table 4.
How do you find the ampacity of a wire?
Start from the conductor's ampacity in NEC Table 310.16 for its size, material and insulation temperature rating, multiply by the adjustment factor for more than three current-carrying conductors and the correction factor for an ambient above 30 °C, then apply the small-conductor limits of 240.4(D): 15 A for 14 AWG copper, 20 A for 12 AWG and 30 A for 10 AWG.
How do you calculate a residential service load?
The optional method for a dwelling (NEC 220.82; 120.82 in NEC 2026) adds the general lighting load per square foot, 1,500 VA for each small-appliance and laundry circuit and the nameplate of fixed appliances, takes the first part at 100% and the rest at 40%, then adds the larger of the air conditioning or heating load. NEC 2026 cut the lighting load from 3 to 2 VA per square foot and the first part from 10 to 8 kVA.
Can an app tell me if my work will pass inspection?
No. The Authority Having Jurisdiction decides what passes, under the edition and amendments it enforces. An app can point to likely violations and the sections behind them; verify them against the code book and in the field. Electrician Helper Pro is an advisory tool, and its output is AI-generated and can be wrong.
Code adoption cycles change. Always confirm the edition and amendments in force with your Authority Having Jurisdiction (AHJ) before permitting work. Questions about the app itself, plans and privacy are answered on the support page.