Quick Hits

Episode 3: Environmental Air Spaces & Plenums (Table 723.20 & Table 723.30)

SLIDE 1 (HOOK / COVER) ⚡ NEC Quick Hit: Low-Voltage Pathways in Plenums (Part 3) ⚡

Can you run open plastic data troughs above a drop ceiling used for return air? Let's check the NEC application tables for environmental air spaces! 👇

SLIDE 2 (FABRICATED DUCTS vs. OTHER PLENUM SPACES) Where Can Nonmetallic Pathways Go?

• Fabricated Ducts (720.22(B)): STRICTLY PROHIBITED. No communications raceways or cable routing assemblies are permitted inside environmental air ducts.

• Other Plenum Spaces (720.22(C) Drop Ceilings): Only Plenum-rated communications raceways and Plenum-rated cable routing assemblies are permitted in ceiling plenums!

SLIDE 3 (OPEN METAL CABLE TRAYS) Supporting Pathways in Ceiling Plenums:

• Plenum-rated communications raceways and plenum-rated cable routing assemblies are permitted when supported by open metal cable trays within air-handling spaces.

• General-Purpose and Riser pathways are completely forbidden in drop-ceiling plenums!

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

Always verify if a ceiling space is an "environmental air plenum" before installing nonmetallic raceways or trough systems. Running standard orange or yellow general-purpose troughs above a return-air drop ceiling will trigger an automatic red tag!

💬 Save this post for your next commercial ceiling inspection! 🔗

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

← View Chapter 7 Home

← Back To Article 722 Home

← Back To Quick Hits Home