Q: When the code refers to a fire alarm system or sprinkler system being off-line for four or more hours in a 24 hour period (fire watch and fire department notification), does the entire system have to be off-line or just a portion to invoke the notification requirement?
A: The NFPA standards do not specifically address this issue, but I have seen The Joint Commission address this in one of their many publications, many years ago. I believe it was the EC News.
Essentially, the answer is no… the entire system does not have to be out of service before it qualifies for the fire watch and notification of the local fire department. Joint Commission said (and I’m paraphrasing here) that a single device out of service does not constitute the need for the fire watch and fire department notification, but an individual circuit or branch would. Many hospitals towers have two sprinkler zones per floor. If one of those zones were out of service for repairs for 4 or more hours in a 24 hour period, then a fire watch and fire department notification would be required.
Other AHJs have taken on the same interpretation as well.