If a wire is broken in a Class B notification circuit, which devices will remain operational?

If a wire is broken in a Class B notification circuit, which devices will remain operational?

• A. All devices beyond the break
• B. Only devices near the panel
• C. All devices between the panel and the break
• D. None

Answer: (C)

Class B notification circuits are arranged as a single path from the control panel to the devices along that run. When a wire breaks, the circuit opens and power can no longer reach devices past the break. The portion of the circuit from the panel up to the break stays intact, so those devices remain operational. That’s why the correct answer is: all devices between the panel and the break. If the break were elsewhere, only the devices before that point would continue to run, while those beyond would be powerless. In contrast, a looped (Class A) circuit can still energize devices beyond a break due to the extra path.

Class B notification circuits are arranged as a single path from the control panel to the devices along that run. When a wire breaks, the circuit opens and power can no longer reach devices past the break. The portion of the circuit from the panel up to the break stays intact, so those devices remain operational. That’s why the correct answer is: all devices between the panel and the break. If the break were elsewhere, only the devices before that point would continue to run, while those beyond would be powerless. In contrast, a looped (Class A) circuit can still energize devices beyond a break due to the extra path.