1. Damaged wiring methods and conductors must be replaced

This first change is found in 2026 NEC Sec. 300.4(C). It addresses wiring methods and conductors that have been damaged by conditions such as water, fire, overloading, corrosion, or similar events. Once the wiring method or conductor is determined to be damaged, the Code treats it as no longer suitable for continued use and requires replacement.

The important field issue is determining whether actual damage exists. A superficial mark on a jacket is not automatically the same as insulation that has been heat degraded, submerged, charred, overloaded, or corroded. The Informational Notes direct users toward industry guidance for evaluating damage.

This is also different from the rules that may permit certain electrical equipment to be reconditioned. For conductors and wiring methods covered here, the practical message is simple: Once they are damaged, do not depend on tape, a patch, or wishful thinking. Replace them.

Key takeaway: Actual damage triggers replacement; the inspection question is whether the wiring method or conductor is truly damaged.

2. 10A branch circuits introduced

The 2026 NEC now formally recognizes 10A branch circuits, but the permission is intentionally narrow. Section 210.23(A) limits these circuits to lighting outlets and dwelling unit exhaust fans installed on bathroom or laundry room lighting circuits. They are not general-purpose receptacle circuits.

That limitation is the most important teaching point. An installer cannot simply place ordinary receptacles on a 10A circuit or assume that every smaller conductor and every breaker is automatically suitable. The branch-circuit rating, conductor size, overcurrent protective device, terminals, wiring method, and equipment listings must all be coordinated.

This change reflects the much lower demand of modern lighting, particularly LED lighting, while still preventing the 10A circuit from becoming a general-purpose substitute for a traditional 15A or 20A circuit.

Key takeaway: 10A is permitted for specific lighting-related loads, not for ordinary general-purpose receptacles.

3. Dwelling general lighting load reduced

Load calculations have been reorganized into Art. 120, and one of the most noticeable dwelling changes appears in Sec. 120.41. For feeder and service calculations, the dwelling general-lighting load is reduced from 3VA/sq ft to 2VA/ft2.

Using the 3,000-sq ft example on the slide, the general-lighting load changes from 9,000VA to 6,000VA before the applicable demand factors are applied. That is a 3,000VA reduction, or approximately one-third.

The caution is that this does not mean every dwelling lighting calculation everywhere in the Code becomes 2VA/ft2. The branch-circuit calculation remains separate. In other words, do not use the reduced feeder-and-service value to incorrectly reduce the required branch-circuit capacity.

Key takeaway: 2VA/ft² applies to the dwelling feeder/service general-lighting calculation; do not apply it indiscriminately to branch-circuit calculations.