Quick Hits

EPISODE 8 — Disconnecting Means Locking Marking Operation Isolating Switches (267.31(D)–(J))

Slide 1 — Hook "Finishing off the disconnecting means section — locking, indicating position, grounded conductor disconnection, and isolating switches."

Slide 2 — Locking, indicating, position & identification

• (D) Lockable open per 110.25 (fused cutouts are exempt from this).

• (E) Must clearly show open/off vs. closed/on.

• (F) Vertically operated handles: "up" = "on" (exception for multi-position switches like double-throw).

• (G) If a building has any combination of feeders/branch circuits/services passing through or supplying it, a permanent plaque/directory at each disconnect location must identify everything else supplying or passing through, and the area each one serves.

Slide 3 — Operation, grounded conductor & isolating switches

• (H) Manually operable (handle-equipped switch/breaker) OR power-operable (as long as it can be opened by hand during a power failure).

• (I) If the disconnect doesn't disconnect the grounded conductor itself, another means (like a pressure-connector terminal/bus) must be provided at that location — multisection switchgear can have this in any marked section.

• (J) If the disconnect lacks visible break contacts, a visible-break isolating switch (meeting specific 268.70(E) sub-requirements and 495.22) is required on its supply side — exempt only for removable truck panels/switchgear units that auto-disconnect when removed.

Slide 4 — Quiz + CTA Q: "For a vertically operated disconnect handle, which position indicates 'on' (absent a multi-position exception)?" A) Down B) Up C) Horizontal D) It doesn't matter

✅ Answer: B — 267.31(F): "up" = "on" for vertically operated handles.

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