Class 4 fault-managed power is a distribution category introduced in NEC Article 726 (2023 edition) for systems that deliver hundreds of watts over small-gauge cable while continuously monitoring for faults and interrupting power in milliseconds. It gives high-power DC lighting and digital-electricity systems a code pathway beyond Class 2 limits.
Fault-managed power continuously monitors the circuit and cuts power in milliseconds when a fault signature appears, which is what lets it carry hundreds of watts on small-gauge cable safely.
Adoption is edition-dependent: engage the AHJ early — a documented DC-adoption failure point — and treat 450V DC fault-managed platforms as the higher-power adjacency to 48V systems.
We advise before we quote. Tell us what you are working on and we will tell you whether this applies to your project.
Assess whether fault-managed power fits your project
