Under what condition is electrical power allowed for manual actuation?

The correct answer is that electrical power is allowed for manual actuation when a reserve power supply is provided. This condition ensures that the manual actuation of the dry chemical extinguishing system can be performed reliably, even if there are issues with the main power supply. Having a reserve power supply guarantees that the system remains operational and accessible during a power failure or other emergencies, thus allowing for effective fire response.

In the context of the NFPA 17 Standard, it’s critical to ensure that fire suppression systems are designed with redundancy in mind. This safeguards against situations where manual actuation could be necessary, ensuring that the extinguishing agents can be released without delay or complication caused by power loss.

Without a reserve power supply, relying on electrical power during manual actuation could hinder the operation of the system. Hence, while testing and potential power failures are relevant considerations, they do not establish a reliable condition for operation compared to the certainty provided by having a reserve power supply in place.