Cause And Effect Matrix For Fire Alarm System Hot! -
Master Guide to the Cause and Effect Matrix for Fire Alarm Systems
The matrix was developed based on:
A poorly designed Cause and Effect matrix is why, in some buildings, a small puff of smoke from toast will shut down the entire HVAC system, recall all elevators, and evacuate 50 floors — while a real fire in a stairwell triggers nothing. cause and effect matrix for fire alarm system
| Cause (Input) | Effect (Output Action) | Delay (sec) | Notes | | :--- | :--- | :--- | :--- | | | O3 (AHU shutdown) | 0 | Immediate stop of HVAC to prevent smoke spread | | | O4 (Stair fan) | 0 | Start pressurization only if multiple detectors confirm | | I2 (Area Smoke - Zone 5) | O1 (Alarm - Zone 5 only) | 0 | Local alarm | | | O2 (Door release - Zone 5) | 0 | Contain smoke | | | O6 (Damper - Zone 5) | 0 | Close associated dampers | | I3 (Pull Station) | O1 (Global Alarm) | 0 | All notification appliances building-wide | | | O5 (Elevator recall) | 10 | Allow elevator to finish descent, then shunt trip | | I4 (Heat Detector - Kitchen) | O1 (Alarm - Local floor only) | 0 | No sprinkler activation (heat detector is supervisory) | | I5 (Sprinkler Flow) | O1 (Global Alarm) | 0 | Confirms fire, overrides smoke detector logic | | | O2 (All doors release) | 0 | Entire floor | | | O3 (AHU shutdown) | 0 | Confirmed fire | | | O5 (Elevator recall) | 0 | Immediate | | I6 (Tamper Switch) | Supervisory signal only | N/A | No evacuation; alert facility manager | Master Guide to the Cause and Effect Matrix
