Ancillary Functions & Interfaces
Relay modules, elevator recall, door release, sprinkler supervision, waterflow systems, monitored dry contacts, device compatibility, and end-of-line modules.
- Explain relay modules and monitored dry contact inputs
- Describe elevator recall and magnetic door release requirements
- Identify sprinkler supervision and waterflow monitoring methods
- Apply device compatibility and listing requirements for system components
Leçon 1
Relay Modules & Monitored Dry Contact Inputs
Control Relay Modules
Fire alarm systems use relay modules to interface with ancillary building systems. A relay module receives a command from the FACP and activates its contacts to control external equipment.
Common Relay Applications
- Elevator recall - sends elevators to ground floor
- Door release - releases magnetic door holders
- HVAC shutdown - stops air handling to prevent smoke spread
- Stairwell pressurization - activates fans to keep stairwells clear
- Monitoring station - transmits alarm signal
Monitored Dry Contact Inputs
A monitored input on the FACP accepts signals from external systems through dry contacts (voltage-free relay contacts). The FACP supervises the input wiring with an EOL resistor to detect faults.
- Sprinkler waterflow switches
- Sprinkler valve tamper switches
- Duct smoke detector contacts
- Kitchen suppression system contacts
Exam Tip
Dry contacts are relay contacts with no voltage applied - the FACP provides the supervision voltage. This is different from powered outputs where the external system provides voltage. Always use dry contacts for FACP inputs.
Relay modules allow the FACP to control building systems (elevators, doors, HVAC) during alarm. Monitored dry contact inputs accept signals from external systems (waterflow, tamper switches) with EOL supervision. Always use dry contacts for FACP input connections.