NBFAA minimum wire size for protective circuit wiring?

NBFAA minimum wire size for protective circuit wiring?

• A. 20 AWG
• B. 22 AWG
• C. 24 AWG
• D. 26 AWG

Answer: (B)

Minimum protective circuit wiring must be thick enough to keep resistance and wear within safe, reliable levels for signaling loops. The NBFAA standard specifies 22 AWG as the smallest allowed for protective circuits, balancing durability, insulation compatibility, and signal integrity for low‑voltage alarm wiring. That’s why 22 AWG is the correct choice: thinner wires (24 AWG or 26 AWG) would have higher resistance and be more prone to damage or voltage drop, and a thicker wire like 20 AWG is acceptable but not the minimum.

Minimum protective circuit wiring must be thick enough to keep resistance and wear within safe, reliable levels for signaling loops. The NBFAA standard specifies 22 AWG as the smallest allowed for protective circuits, balancing durability, insulation compatibility, and signal integrity for low‑voltage alarm wiring. That’s why 22 AWG is the correct choice: thinner wires (24 AWG or 26 AWG) would have higher resistance and be more prone to damage or voltage drop, and a thicker wire like 20 AWG is acceptable but not the minimum.