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📱 EPISODE 2 — Article 348 (Part 2 of 2)

Securing, Supporting & Grounding — Article 348 Complete!

SLIDE 1 — Trimming & Securing (348.28, 348.30(A))
✂️ TRIMMING (348.28)

Cut ends must be TRIMMED to remove rough edges — UNLESS using fittings that thread directly into the convolutions.

🛠️ SECURING (348.30(A))
General rule: secured within 12 in. (300mm) of each box/cabinet/termination, supported at intervals not exceeding 4½ ft (1.4m). Cable ties used for this MUST be listed and identified for securement/support.

4 Exceptions for flexibility-driven installs:
1️⃣ Fished through concealed spaces where supporting is impracticable
2️⃣ Where flexibility is necessary AFTER install — lengths from last secure point capped by size: 3 ft (½–1¼ in.), 4 ft (1½–2 in.), 5 ft (2½ in.+)
3️⃣ ≤6 ft from luminaire terminal for tap connections (410.117(C))
4️⃣ ≤6 ft from last secure point, connecting within accessible ceiling to luminaire/equipment

SLIDE 2 — Supports & Couplings
🛠️ HORIZONTAL RUN SUPPORT (348.30(B))

Horizontal FMC runs supported through framing member openings at intervals ≤4½ ft, secured within 12 in. of termination points — permitted.

🔗 COUPLINGS/CONNECTORS (348.42)
Simple but important rule: angle connectors shall NOT be concealed — they need to stay accessible/visible.

SLIDE 3 — Grounding: The 6-Foot Rule (348.60)
⚠️ CRITICAL SAFETY RULE — MEMORIZE THIS

FMC is NOT reliably suited for grounding purposes when it exceeds a certain length. Per UL 1: FMC longer than 6 feet is NOT considered suitable for grounding.

🔑 The rule: if the total ground-fault return path through FMC exceeds 6 feet, OR the circuit's OCPD exceeds 20 amperes, a SEPARATE EGC must be installed with the circuit conductors (per 250.118(A)(5)).

📌 Classic use case: motor connections needing vibration isolation, or floodlights/equipment needing post-install adjustment — that's when FMC's flexibility matters, and that's exactly when this 6-ft/20A rule kicks in.

SLIDE 4 — Fixed vs. Flexible Installations + Final Exam Question
🔀 TWO SCENARIOS (348.60(A)–(D))

(A) Fixed installation: FMC CAN serve AS the EGC itself (per 250.118(A)(5)) — WHEN flexibility isn't required after installation.

(B) Flexible installation: a SEPARATE EGC is REQUIRED where flexibility is needed to minimize vibration transmission or allow equipment movement after install.

(C) & (D): EGCs follow 250.134; equipment bonding jumpers follow 250.102.

🎉 That wraps up Article 348 — Flexible Metal Conduit!

🧠 FINAL EXAM QUESTION FOR ARTICLE 348

Q: Per 348.60, FMC is not considered suitable for grounding purposes if the ground-fault return path exceeds what length, OR the circuit OCPD exceeds what rating?

A) 3 feet / 15 amperes
B) 6 feet / 20 amperes
C) 10 feet / 30 amperes
D) 6 feet / 15 amperes

(Drop your final answer 👇)

Article 348 = DONE ✅ FOLLOW for more daily quick-hit NEC study notes ⚡ #JoshTheSparky #NEC2026 #ElectricianLife

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