Quick Hits

📱 EPISODE 1 — Article 350 (Part 1 of 2)

Liquidtight Flexible Metal Conduit (LFMC) — Scope, Uses & Sizing

SLIDE 1 — What Is LFMC?
💧 FLEXIBLE + LIQUIDTIGHT — "SEALTITE"

Article 350 covers LFMC — flexible metal conduit designed for WET locations or exposure to oil/coolants, max temp 140°F (60°C). NOT intended for gasoline or light petroleum solvents UNLESS specifically marked for that use.

If properly marked, LFMC CAN be used for direct burial. It's also on the permitted wiring methods list for services (230.43) — but limited to 6 ft max with an equipment bonding jumper per 250.102. Beyond that, unlimited lengths ARE allowed if a separate EGC is installed.

📋 Listing (350.2): LFMC AND its fittings — both listed.

♻️ Reconditioned equipment (350.3): LFMC and its fittings are NOT permitted to be reconditioned and installed.

SLIDE 2 — Uses Permitted (350.10)
✅ WHERE LFMC EXCELS

✅ Where flexibility OR protection from machine oils, liquids, vapors, or solids is needed
✅ Hazardous (classified) locations, where Chapter 5 specifically permits
✅ Direct burial — IF listed and marked for that purpose
✅ Conductors/cables rated HIGHER than LFMC's listed temp rating CAN be used inside — as long as they don't OPERATE above LFMC's rating
✅ Encased in concrete — IF listed/marked for direct burial AND installed per 350.42

🚫 USES NOT PERMITTED (350.12)
Simple: NOT permitted where subject to physical damage.

SLIDE 3 — Sizing Rules (350.20)
📏 MINIMUM & MAXIMUM

Minimum: trade size ½ — Exception: trade size ⅜ permitted under the SAME limited conditions as FMC (per 348.20(A))
Maximum: trade size 4

🔢 CONDUCTOR FILL (350.22)
🔹 Trade sizes ½–4 → per Chapter 9, Table 1 percentage fill
🔹 Trade size ⅜ → per Table 348.22, using the "Fittings Outside Conduit" columns specifically

SLIDE 4 — Bends & Trimming + Exam Question
🔄 BENDS (350.24)

• Manual bending permitted, no auxiliary equipment needed

• Bend radius per Chapter 9, Table 2, "Other Bends" column

• Max 360° total bends per run between pull points

✂️ TRIMMING (350.28)
Cut ends must be trimmed INSIDE AND OUTSIDE to remove rough edges. This matters extra here — proper trimming is necessary for correctly installing the STEEL GROUNDING FERRULE, which maintains ground continuity of the steel sheath.

🧠 TEST YOURSELF

Q: Per the informational note in 350.1, what is the maximum length LFMC can be used for services (per 230.43) without requiring a separate EGC, as long as an equipment bonding jumper is installed?

A) 3 feet
B) 6 feet
C) 10 feet
D) Unlimited length

(Drop your answer 👇)

FOLLOW — Part 2 covers securing/supporting and the grounding rules ⚡ #JoshTheSparky #NEC2026 #ElectricianLife

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