Quick Hits

Episode 4: Surface Markings & The "FRR" Designation (772.120)

SLIDE 1 (HOOK / COVER) ⚡ NEC Quick Hit: Decoding "FRR" Cable Markings (Part 4) ⚡ 

What does "FRR" stamped on a cable jacket actually mean? Section 772.120 establishes mandatory surface markings for fire-resistive cable systems. Let's finish Article 772! 👇

SLIDE 2 (SURFACE MARKING REQUIREMENTS) What Must Be Printed on the Cable:

• The FRR Suffix: System cables and conductors must be surface marked with the suffix "FRR" (Fire-Resistive Rating).

• Duration & ID: Must also display the circuit integrity duration in hours (e.g., 2-hour rating) and the specific system identifier code.

SLIDE 3 (INSPECTING BEFORE THE PULL) Verification on the Job Site:

• Always verify that the jacket print matches the engineering submittal and the fire-resistive system listing before pulling wire into a stairwell or shaft.

• Inspect support hardware, boxes, and raceways to ensure every component bears the correct system identification.

SLIDE 4 (WRAP-UP) 💡 Apprentice Pro-Tip: 

Inspectors will look directly at the cable jacket print for the FRR marking and hour duration. Always leave a visible section of cable jacket exposed inside junction boxes for easy AHJ verification!

💬 Save this post for your final code review on fire-resistive cable systems! 🔗 

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