Which statement about pre-discharge alarms is true?

Which statement about pre-discharge alarms is true?

• A. They may be powered by backup electrical power
• B. They must be pneumatically powered
• C. They can be powered by solar power
• D. They do not require a decibel rating

Answer: (B)

Pre-discharge alarms must warn occupants before a suppression agent is released, and they have to stay reliable even if electrical power fails during a fire. Because of that, the alarm signaling is typically driven by a pneumatic (air pressure) source, which remains operable independent of electrical power conditions. Solar power isn’t a practical or reliable method for these critical, always-on signals, and backup electrical power alone doesn’t guarantee operation if the electrical system is compromised or if the pneumatic path is the intended fail-safe. Additionally, audible warnings for these alarms require a defined decibel rating to ensure the sound level is adequate for occupants to hear and respond.

Pre-discharge alarms must warn occupants before a suppression agent is released, and they have to stay reliable even if electrical power fails during a fire. Because of that, the alarm signaling is typically driven by a pneumatic (air pressure) source, which remains operable independent of electrical power conditions. Solar power isn’t a practical or reliable method for these critical, always-on signals, and backup electrical power alone doesn’t guarantee operation if the electrical system is compromised or if the pneumatic path is the intended fail-safe. Additionally, audible warnings for these alarms require a defined decibel rating to ensure the sound level is adequate for occupants to hear and respond.