Quick Hits

Episode 10 — Location in Circuit: Branch Taps and the 10-Ft/25-Ft Feeder Tap Rules

Covers: 240.21 (general), 240.21(A), 240.21(B)(1)–(2)

Hook: Overcurrent protection normally goes right where a conductor gets its power. Tap conductors are the big exception — this is the famous "10-foot tap rule."

Slide 2: The default: every ungrounded conductor gets protection at the point it receives its supply. Branch-circuit taps follow 210.19/210.20 instead. Feeder taps can skip protection at the tap point itself under specific conditions — and the round-up rule from 240.4(B) never applies to tap conductors.

Slide 3: The 10-ft tap rule: tap conductors up to 10 ft long can skip local OCPD protection if their ampacity covers the combined load and matches the downstream OCPD/equipment rating, they don't extend past the enclosure they feed into, they're enclosed in raceway except right at the tap connection, and — if they leave the enclosure where the tap is made — their ampacity is at least 1/10 of the feeder's OCPD rating. The 25-ft tap rule is similar but requires ampacity of at least 1/3 of the feeder OCPD, termination in a single breaker/fuse set, and raceway protection.

Quiz: Under the 10-ft tap rule, if the tap leaves its enclosure, what's the minimum tap conductor ampacity relative to the feeder OCPD?
Answer: At least 1/10 (10%) of the feeder OCPD rating.

CTA: Follow — transformer taps, high-bay taps, and outside taps are next.

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