Sparky Edition #020NEC 110.9–110.10 Interrupting Rating & SCCR (3/10)

A breaker with an adequate interrupting rating does not automatically make downstream equipment acceptable.

Permit Proof Chain

01Code TriggerIdentify why the section applies.
02Sheet EvidenceShow the requirement where the reviewer needs it.
03Coordination OwnerTie the requirement to the responsible discipline or party.
04Field ProofConfirm the installed condition can be verified.

110.9 Interrupting rating

Equipment intended to interrupt current at fault levels must have an interrupting rating at the circuit’s nominal voltage that is at least equal to the available fault current at its line terminals. Think: available fault current ≤ interrupting rating.

110.10 Available fault current, SCCR

The overcurrent protective devices, equipment short-circuit current ratings, and other circuit characteristics must be selected and coordinated with the available fault current so a fault is cleared without extensive damage to the electrical equipment.

The example from Daily Code Talk

Available fault current = 22 kA. Breaker interrupting rating = 35 kA. Equipment SCCR = 10 kA. The breaker may interrupt the fault. The equipment SCCR is still below the available fault current. That equipment is not adequately rated for that location.

Field tip

For VFDs, control panels, HVAC equipment, and pump packages, compare available fault current vs equipment SCCR vs OCPD interrupting rating. All three matter. Hub: SCCR hub. Next: 110.11–110.13.

Code basis

NEC 2026 Article 110 education from the owner-provided Daily Code Talk. Confirm adopted edition and the project short-circuit study. Not a coordination study.

PE-led project support

Need this applied to a live project?

MasterBuild Consulting helps owners, architects, GCs, and project teams turn code questions into permit-ready MEP decisions before review comments, field changes, or inspection issues cost more time.

Sparky Edition uses the 2026 NEC as model-code education. Verify the locally adopted NEC edition, amendments, listings, and AHJ path before project use.

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