FIGURE 1. WIRING DIAGRAM:
3
2
1
3
2
1
+
–
–
+
+–
REMOTE ANNUNCIATOR
CAUTION: DO NOT LOOP WIRE 
UNDER TERMINAL 1 OR 2.
BREAK WIRE RUN TO PROVIDE 
SUPERVISION OF CONNECTIONS.
UL LISTED COMPATIBLE 
CONTROL PANEL
OPTIONAL RETURN LOOP
C0100-01
FIGURE 2. ROTARY ADDRESS SWITCHES:
TENS ONES
9
10
11
1 2
1 3
1 4
1 5
8
7
6
5
4
3
2
1
0
9
8
7
6
5
4
3
2
1
0
C0162-00
TAMPER-RESISTANCE
Models SD355, SD355T and AD355 include a tamper-resistant capability that 
prevents its removal from the bracket without the use of a tool. Refer to the 
base manual for details on making use of this capability.
TESTING
Before  testing,  notify  the  proper  authorities  that  the  system  is  undergoing 
maintenance, and will temporarily be out  of  service. Disable  the  system to 
prevent unwanted alarms.
All sensors must be tested after installation and periodically thereafter. Test-
ing  methods  must  satisfy  the  Authority Having Jurisdiction (AHJ). Sensors 
offer maximum performance when tested and maintained in compliance with 
NFPA 72. The sensor can be tested in the following ways:
A.  Functional: Magnet Test (P/N M02-04-01 or M02-09-00) 
   This sensor can be functionally tested with a test magnet. The test mag-
net electronically simulates  smoke in the  sensing chamber, testing the 
sensor electronics and connections to the control panel.
  1.  Hold the test magnet in the magnet test area as shown.
  2.  The sensor should alarm the panel.
   Two LEDs on the sensor are controlled by the panel to indicate sensor 
status. Coded  signals, transmitted from the panel, can  cause the LEDs 
to blink, latch on, or latch off. Refer to the control panel technical docu-
mentation for sensor LED operation and expected delay to alarm.
FL-400-002  1  I56-3660-002R
This sensor must  be installed in compliance with the control panel  system 
installation manual. The installation must meet the requirements of the Au-
thority Having Jurisdiction (AHJ). Sensors offer maximum performance when 
installed in compliance with the National Fire Protection Association (NFPA); 
see NFPA 72. 
GENERAL DESCRIPTION
Model  SD355, SD355T and  AD355  are  addressable sensors that combine  a 
state-of-the-art photoelectronic sensing chamber with communications. The 
sensors transmit an analog representation of smoke density over a communi-
cation line to a control panel. Rotary decade switches are provided for setting 
the sensor’s address.
Two LEDs on the sensor are controlled by the panel to indicate sensor status. 
An output is provided for connection to an optional remote LED annunciator 
(P/N RA400Z). Models AD355 and SD355T combine a photoelectronic sens-
ing chamber and 135°F (57.2°C) fixed temperature heat detector.
SPACING
Fire-Lite recommends spacing sensors in compliance with NFPA 72. In low 
air flow applications with smooth ceilings, space sensors 30 feet apart. For 
specific information regarding sensor spacing, placement, and special appli-
cations, refer to  NFPA  72 or the System Smoke Detector Application Guide 
available from Fire-Lite.
WIRING INSTRUCTIONS
All wiring must be installed in compliance with the National Electrical Code, 
applicable local codes, and any special requirements of the Authority Having 
Jurisdiction. Proper wire gauges should be used. The installation wires should 
be color-coded to limit wiring mistakes and ease system troubleshooting. Im-
proper connections  will  prevent  a  system  from  responding properly in  the 
event of a fire.
Remove power from the communication line before installing sensors.
1.   Wire the sensor base (supplied separately) per the wiring diagram, see 
Figure 1.
2.   Set the desired address on the sensor address switches, see Figure 2.
3.   Install the  sensor  into the  sensor  base. Push the  sensor into the  base 
while turning it clockwise to secure it in place.
4.   After all sensors have been installed, apply power to the control unit and 
activate the communication line.
5.   Test the sensor(s) as described in the TESTING section of this manual.
Dust covers provide limited protection against airborne dust particles during 
shipping. Dust covers must be removed before the sensors can sense smoke. 
Remove sensors prior to heavy remodeling or construction.
I56-3660-002R
INSTALLATION AND MAINTENANCE INSTRUCTIONS
SD355, SD355T and AD355
Addressable Photoelectric Smoke Sensors
SPECIFICATIONS
Operating Voltage Range:  15 to 32 VDC
Standby Current:  300µA @ 24 VDC (one communication every 5 seconds with LED blink enabled)
Maximum Alarm Current (LED on):  6.5 mA @ 24 VDC
Operating Humidity Range:  10% to 93% Relative Humidity, Non-condensing
Operating Temperature Range:  32°F to 120°F (0°C to 49°C); SD355
Operating Temperature Range:  32°F to 100°F (0°C to 38°C); SD355T and AD355
Height:  2.0˝ (51 mm) installed in B350LP Base
Diameter:  6.2˝ (155 mm) installed in B350LP Base
Weight:  5.2 oz. (147 g)
One FireLite Place
Northford, CT 06472
Phone: 203.484.7161