Which cable type is permitted to be installed exposed in a plenum space?

Which cable type is permitted to be installed exposed in a plenum space?

• A. FPLP
• B. FPL
• C. NPLP
• D. NPLF

Answer: (A)

Plenum spaces require cables with a rating that ensures low smoke and flame spread when installed in air-handling spaces. The designation at the end of the cable type tells you its rating for that environment. FPLP has a P at the end, marking it as plenum-rated, so it’s approved to be installed exposed in a plenum. That’s why it’s the appropriate choice for a space that serves as a return air duct. The other options either lack the plenum rating or are suited to different installation conditions, so they aren’t permitted for exposed plenum use.

Plenum spaces require cables with a rating that ensures low smoke and flame spread when installed in air-handling spaces. The designation at the end of the cable type tells you its rating for that environment. FPLP has a P at the end, marking it as plenum-rated, so it’s approved to be installed exposed in a plenum. That’s why it’s the appropriate choice for a space that serves as a return air duct. The other options either lack the plenum rating or are suited to different installation conditions, so they aren’t permitted for exposed plenum use.