Fire Protection Design Manual - Office of Construction and Facilities ...

Explanation of Fire Alarm Interface with Elevators
September-2011
Notes:
• There can be many variations of the accompanying “Pictorial Representation of Fire Alarm Interface
with Elevators.”
• In this example, the smoke and heat detectors are addressable initiating devices and the operating
relays are “hardwired.”
• To achieve supervision, the relay circuits are operated from supervised control circuits. Sometimes
NACs (Notification Appliance Circuits) are used to accomplish this function.
• The supervisory initiating device that monitors the power for the shunt trip circuit is connected to a
supervisory IDC (Initiating Device Circuit).
• The scenario assumes that:
1. There is a sprinklered elevator hoistway.
2. Means to disconnect the main line power to the elevator is via a shunt trip breaker.
3. System operation is in accordance with NFPA 72.
4. Relay (R5) and an IDC (Initiating Device Circuit) have been included to provide indication
(via a supervisory alarm) of absence of voltage (power) to operate shunt trip breaker.
Components Function
R1 --------------- Signal to elevator controller for recall to designated level.
R2 --------------- Signal to elevator controller for recall to alternate level.
R3 --------------- Signal to elevator controller for firefighter notification.
R4 --------------- Signal to activate shunt trip relay.
R5 --------------- Supervisory relay to monitor presence of voltage (power) to operate shunt trip
breaker.
SCC1 ----------- Supervised Control Circuit for operating R1.
SCC2 ----------- Supervised Control Circuit for operating R2.
SCC3 ----------- Supervised Control Circuit for operating R3.
SCC4 ----------- Supervised Control Circuit for operating R4.
IDC1------------ Initiating Device Circuit to supervise R5 contacts (monitoring power to operate shunt
trip breaker).
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