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📱 EPISODE 2 — Article 334 (Part 2 of 3)

Exposed Work, Bending Radius & Support

SLIDE 1 — Exposed Work Rules (334.15)
📍 FOLLOWING THE SURFACE

Cable in exposed work must closely follow the building finish surface or running boards (334.15(A)).

🛡️ PHYSICAL DAMAGE PROTECTION (334.15(B))
Where protection is needed: RMC, IMC, EMT, Schedule 80 PVC, RTRC-XW, or other approved means.
📏 Passing through a floor: protection must extend at least 6 in. (150mm) above the floor, with a bushing/adapter to prevent abrasion where the cable enters/exits.

Type NMC in shallow chases/grooves gets protected per 300.6(F) and covered with plaster/adobe/similar finish.

SLIDE 2 — Unfinished Basements & Crawl Spaces (334.15(C))
🏚️ SPECIAL RULES FOR BASEMENTS

Running cable at angles to joists in unfinished basements/crawl spaces:
✅ Cables with 2+ 6 AWG or 3+ 8 AWG conductors → CAN be secured directly to the lower edges of joists
✅ Smaller cables → must run through bored holes OR on running boards

On basement WALLS: NM can be in listed conduit/tubing (with abrasion protection at entry/exit), sheath must extend at least ¼ in. (6mm) into the box, and be secured within 12 in. of where it enters the conduit. Metal conduit/boxes need proper EGC connection per 250.86/250.148.

SLIDE 3 — Framing Members & Bending Radius
📐 THROUGH/PARALLEL TO FRAMING (334.17)

Protect per 300.6 — grommets required by 300.6(B)(1) must stay in place and be LISTED for cable protection.

🔄 CABLE ENTRIES (334.19)
Sheath must extend at least ¼ in. (6mm) beyond any cable clamp/entry point inside the box/enclosure.

📐 BENDING RADIUS (334.24)
Minimum bend radius = 5x the cable diameter. For FLAT cables: use the MINOR diameter when bending on the flat side; use the MAJOR diameter for all other bends.

Also — accessible attics (334.23) follow the same guard-strip rules referenced back in 320.23.

SLIDE 4 — Securing & Supporting + Exam Question
🛠️ SUPPORT INTERVALS (334.30)

✅ Support/secure at intervals not exceeding 4½ ft (1.4m)
✅ Within 12 in. (300mm) of every cable entry into a box/cabinet/fitting
✅ Max cable length between entry point and closest support: 18 in. (450mm)
🚫 Flat cables CANNOT be stapled on edge

Exceptions for unsupported cable (334.30(B)): fished through concealed spaces where impracticable, OR ≤4½ ft from last support to a luminaire/equipment connection in an accessible ceiling (dwellings only).

🧠 TEST YOURSELF

Q: Per 334.24, what is the minimum bending radius for Type NM or NMC cable?

A) 3 times the cable diameter
B) 5 times the cable diameter
C) 7 times the cable diameter
D) 10 times the cable diameter

(Comment your answer 👇)

FOLLOW — Part 3 wraps up boxes/fittings, ampacity, and construction specs ⚡ #JoshTheSparky #NEC2026 #ElectricianLife

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