How many sprinkler tamper switches can you terminate to a single initiating zone on a fire alarm panel?
The magic number is set by your local AHJ, applicable building codes, and standards but averages around eight. Most AHJ’s would like to see separate annunciation for each switch or valve within a common sprinkler room and this is often possible with an addressable panel’s liquid crystal display (LCD). At the very least, they will insist on having a separate zone for the back-flow preventer which often utilizes two switches (one on the inlet side and one on the outlet side) or the main water entry valve. You must use common sense when laying out your sprinkler zones and the same applies to the control valves inside a common sprinkler room. Identifying a mis-aligned valve (or defective switch) can become more time consuming when they’re commoned to a single zone.
