Quick Hits

📱 EPISODE 1 — Article 336 (Part 1 of 2)

Type TC Cable — Scope & Uses Permitted

SLIDE 1 — What Is Type TC Cable?
🔌 POWER AND CONTROL TRAY CABLE

Article 336 covers Type TC cable — used for power, lighting, control, and signal circuits, tested to ANSI/UL 1277. Listing (336.2) covers the cable itself, PLUS ties/cleats/staples/straps/hangers, AND connecting fittings.

This is a workhorse cable in industrial and commercial settings — especially anywhere cable trays are used.

SLIDE 2 — Core Uses Permitted (336.10)
✅ THE BASICS

✅ Power, lighting, control, and signal circuits
✅ Cable trays (including ones with mechanically discontinuous segments up to 1 ft)
✅ Raceways
✅ Outdoor, supported by a messenger wire
✅ Class 1 circuits per Article 724
✅ Non-power-limited fire alarm circuits (if conductors comply with 760.49)
✅ Direct buried (if identified for the use)
✅ Hazardous locations (where other articles specifically permit)
✅ Must resist moisture/corrosive agents in wet locations

SLIDE 3 — TC-ER: Exposed Runs Without a Raceway
🔓 THE TC-ER EXCEPTION — CABLE TRAY TO EQUIPMENT

TC-ER cable (surface marked "TC-ER") can run EXPOSED between a cable tray/raceway/enclosure and utilization equipment IF:
✅ Installed in industrial establishments, qualified-persons-only maintenance
✅ Continuously supported/protected against physical damage (struts, angles, channels)
✅ Secured at max 6 ft intervals
✅ EGC provided within the cable (or, for conductors ≤6 AWG, one or more insulated conductors identified as the EGC per 250.119)

📌 Exception: if NOT subject to physical damage, TC-ER can transition up to 6 ft WITHOUT continuous support between tray/raceway/enclosure/equipment — but it must still be mechanically supported to maintain the minimum bend radius.

SLIDE 4 — TC-ER-JP for Dwellings + Service-Entrance Use + Exam Question
🏠 RESIDENTIAL USE (336.10(9))

Type TC-ER-JP (power + control conductors combined) IS permitted for branch circuits/feeders in ONE- and TWO-family dwellings! Interior wiring follows Article 334 Part II rules; exterior wiring follows Article 340 Part II rules.

⚡ Exception: when connecting a generator + associated equipment with 75°C+ rated terminals, ampacity ISN'T limited by 334.80/340.80.

🔌 SERVICE-ENTRANCE USE (336.10(12))
TC cable CAN be used as service-entrance conductors — but ONLY if identified for that use and marked Type TC-ER.

🧠 TEST YOURSELF

Q: Per 336.10(9), Type TC-ER-JP cable is permitted for branch circuits and feeders in what type of occupancy?

A) Multi-family dwellings only
B) Commercial buildings only
C) One- and two-family dwelling units
D) Industrial establishments only

(Drop your answer 👇)

FOLLOW — Part 2 wraps up bending radius, support, ampacity, and construction specs ⚡ #JoshTheSparky #NEC2026 #ElectricianLife

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