Quick Hits

Episode 4: Cable Substitutions & Application Matrix (722.120 – 722.122)

SLIDE 1 (HOOK / COVER) ⚡ NEC Quick Hit: Cable Substitutions & Applications (Part 4) ⚡

Got plenum cable on hand when you only need riser? Can you substitute it? Table 722.122 holds the answer. Let's master low-voltage cable substitutions! 👇

SLIDE 2 (THE CABLE SUBSTITUTION HIERARCHY) Decoding Table 722.122:

• Upgrading is Legal: You can always substitute a higher fire-resistant cable into a lower-requirement space (e.g., using Plenum CL3P in a Riser CMR or General Purpose application).

• Downgrading is Illegal: You can never install a general-purpose cable into a riser or plenum shaft!

SLIDE 3 (APPLICATION MATRIX - TABLE 722.120) Where Can Each Cable Go?

• Plenum (P): Permitted in air-handling ducts, plenums, risers, and general spaces.

• Riser (R): Permitted in vertical floor runs and general spaces (not air-handling plenums).

• General Purpose: Restricted to standard building runs (walls, ceilings) out of vertical risers and plenums.

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

Always check the cable jacket print before pulling! Pulling a general-purpose CM cable into a vertical riser shaft or air plenum will instantly fail your rough-in inspection.

💬 Save this post for your final code review on low-voltage cable pulling! 🔗

More code breakdowns and study tools at www.JoshTheSparky.com

← View Chapter 7 Home

← Back To Article 721 Home

← Back To Quick Hits Home