Where should a listed relay that initiates fire safety functions be located in relation to the controlled circuit?

Where should a listed relay that initiates fire safety functions be located in relation to the controlled circuit?

• A. Within 1 foot
• B. Within 3 feet
• C. Within 5 feet
• D. Within 10 feet

Answer: (B)

The key idea is that a listed relay which starts fire safety functions must be placed very close to the circuit it controls. Keeping the relay within three feet of the controlled circuit helps ensure a fast, reliable, and predictable initiation of those functions. Shorter control runs minimize impedance, reduce the chance of voltage drop or interference, and limit opportunities for stray coupling or misoperation that could delay or falsely trigger safety actions. It also keeps the relay and the devices it controls within the same protected signaling path, which aligns with listing requirements for ensuring the intended function performs as designed.

The key idea is that a listed relay which starts fire safety functions must be placed very close to the circuit it controls. Keeping the relay within three feet of the controlled circuit helps ensure a fast, reliable, and predictable initiation of those functions. Shorter control runs minimize impedance, reduce the chance of voltage drop or interference, and limit opportunities for stray coupling or misoperation that could delay or falsely trigger safety actions. It also keeps the relay and the devices it controls within the same protected signaling path, which aligns with listing requirements for ensuring the intended function performs as designed.