Quick Hits

EPISODE 14 — Braid-Covered Conductors for 1kva, Insulation Shielding & Danger Signs — Article 305 FINALE (305.38, 305.40, 305.42)

Slide 1 — Hook "Final episode of Article 305! Closing with three sections that have NO Article 300 counterpart — unique to medium/high-voltage installations."

Slide 2 — 305.38 Braid-covered insulated conductors

• Exposed runs of braid-covered insulated conductors need a FLAME-RETARDANT braid. If the conductor doesn't have that built in, a flame-retardant saturant has to be applied to the braid after installation.

• At terminations, the treated braid covering gets stripped back a safe distance based on operating voltage — where practicable, not less than 1" per kV of conductor-to-ground voltage.

Slide 3 — 305.40 & 305.42

• 305.40 Insulation shielding: metallic/semiconducting shielding components on shielded cable must be removed for a distance based on circuit voltage and insulation type, with stress-relief means provided at all factory-applied shielding terminations. Metallic shielding (tapes/wires/braids or combinations) must connect to an EGC, equipment grounding busbar, or grounding electrode.

• 305.42 Danger signs: DANGER signs must be conspicuously posted at every access point to conductors in raceway and cable systems — meeting 110.21(B), readily visible, reading exactly: "DANGER — HIGH VOLTAGE — KEEP OUT."

Slide 4 — Quiz + CTA Q: "What exact wording must a required danger sign display at medium/high-voltage conductor access points?" A) "WARNING — ELECTRICAL HAZARD" B) "DANGER — HIGH VOLTAGE — KEEP OUT" C) "CAUTION — QUALIFIED PERSONNEL ONLY" D) "NOTICE — HIGH VOLTAGE AREA"

✅ Answer: B — 305.42 specifies this exact wording.

CTA: 🎉 That's a wrap on ALL of Article 305 — General Requirements for Wiring Methods Over 1000V! Follow for more daily quick-hit study notes as we move into the cable-type articles next (starting with Article 310, Conductors for General Wiring).

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