Can branch circuits supplying fire alarm equipment be used to supply other loads?

The foundation for the correct answer lies in the safety requirements and operational integrity necessary for fire alarm systems. Fire alarm circuits must be kept separate from other loads to ensure their reliability and performance during emergencies. Fire alarm systems are critical life safety components, and if these circuits were to be shared with other loads, any issues like overloads or faults could compromise the function of the fire alarm, potentially leading to catastrophic consequences.

Having dedicated circuits for fire alarm systems is consistent with the National Fire Alarm and Signaling Code (NFPA 72), which mandates that fire alarm systems should have their own power supplies and circuits to ensure they are operational at all times, regardless of conditions that may affect other non-life-safety related circuits.

While it is acknowledged that some codes might allow for limited sharing under specific scenarios—typically involving very controlled environments—these exceptions are the minority and still require rigorous oversight to ensure that safety is not compromised. Therefore, the principle that fire alarm circuits must remain dedicated underscores the paramount importance of keeping life safety systems operational, particularly in emergencies.