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📱 EPISODE 1 — Article 330 (Part 1 of 3)

Type MC Cable — Scope, Listing & Uses Permitted

SLIDE 1 — What Is Type MC Cable?
🔌 METAL-CLAD CABLE BASICS

Type MC cable is rated up to 2000V in sizes 18 AWG+ (copper/nickel-coated copper) or 12 AWG+ (aluminum/copper-clad aluminum).

Variations to know:
🔹 2400V–35,000V → medium-voltage, marked "Type MV or MC," covered by Article 315
🔹 MC-HL → rated up to 35,000V, suitable for hazardous locations, gas/vapor tight sheath
🔹 MC-OF → composite electrical + optical fiber cable

Three sheath designs exist: interlocked metal tape, corrugated metal tube, smooth metal tube — sometimes with a nonmetallic jacket over the sheath.

📋 Listing (330.2): the CABLE, plus ties/staples/straps/hangers, AND the fittings used to connect it to boxes/equipment — ALL must be listed and identified.

SLIDE 2 — General Uses Permitted (330.10(A))
✅ WHERE MC CABLE CAN GO — IT'S VERSATILE

MC cable is permitted for:
✅ Services, feeders, AND branch circuits
✅ Power, lighting, control, signal circuits
✅ Indoors OR outdoors
✅ Exposed OR concealed
✅ Direct buried (if identified for it)
✅ Cable tray (if identified for it)
✅ Any raceway
✅ Aerial cable on a messenger
✅ Hazardous locations (where other articles specifically permit)
✅ Dry locations, embedded in plaster on brick/masonry (NOT damp/wet)

This is one of the most flexible wiring methods in the whole Code.

SLIDE 3 — Damp/Wet Locations & Grouping Rule
💧 DAMP OR WET LOCATIONS (330.10(A)(11))

MC cable CAN go in damp/wet locations IF a jacket is provided over the metallic covering AND one of these is true:
a) The metallic covering is moisture-impervious
b) A moisture-impervious jacket sits UNDER the metal covering
c) The insulated conductors under the covering are listed for wet locations

Exception: copper-alloy armor that's already moisture-impervious doesn't need the jacket.

⚡ SINGLE-CONDUCTOR GROUPING (330.10(A)(12))
Where single conductors are used, ALL phase conductors (and the grounded conductor, if used) must be GROUPED TOGETHER — this minimizes induced voltage on the sheath. Don't run them separately.

SLIDE 4 — Uses NOT Permitted + Exam Question
🚫 WHERE MC CABLE CANNOT GO (330.12)

❌ Subject to physical damage
❌ Destructive corrosive conditions UNLESS the sheath/armor resists it or is protected:

• Direct buried or embedded in concrete (unless identified for direct burial)

• Exposed to cinder fills, strong chlorides, caustic alkalis, chlorine/hydrochloric acid vapors

🧠 TEST YOURSELF

Q: Per 330.10(A)(12), where single-conductor cables are used, what must be done with the phase conductors (and grounded conductor, if used)?

A) They must be run in separate raceways
B) They must be grouped together to minimize induced voltage on the sheath
C) There is no requirement — they may be run individually
D) They must be spaced at least 6 inches apart

(Drop your answer 👇)

FOLLOW — Part 2 covers bending radius, securing/supporting, and installation specifics ⚡ #JoshTheSparky #NEC2026 #ElectricianLife

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