Smoke Detector Specifications
Electrical Specifications
LED Modes
LED Mode
Power up
Operating Voltage
Nominal: 12/24 V non-polarized
2-wire: 8.5 V - ꢀ5 V
Green LED Red LED
Condition
Duration
Blink every Blink every 10 Initial LED
80 seconds
4-wire: 10 V - ꢀ5 V
10 seconds seconds
status
Maximum Ripple Voltage ꢀ0% of applied voltage (peak to peak)
indication
Standby Current
2-wire: 50 µA maximum average
4-wire: 50 µA maximum average
Normal
(standby)
Blink every 5 off
seconds
Peak Standby Current
Maximum Alarm Current
2-wire: 100 µA
4-wire: n/a
Out of
sensitivity
off
off
off
Blink every 5
seconds
2-wire: 2WTR-B: 1ꢀ0 mA limited by control
panel
2WTA-B: 1ꢀ0 mA**
4-wire: 4WTA-B, 4WTR-B: ꢀ5 mA
4WTAR-B, 4WITAR-B: 50 mA
**Direct Power (Non-reverse Polarity): 1ꢀ0
mA limited by panel. Reverse Polarity Power:
ꢀ0 mA for the 2WTA-B in alarm; 12 mA for all
other 2WTA-B units on the loop. Add 25 mA
for the RRS-MOD reversing relay alarm current.
Freeze
trouble
Blink every 10
seconds
Alarm
Solid
Power Up Sequence for LED Indication
Condition
Duration
Initial LED
status
indication
80 seconds
Architect/Engineer Specifications
Alarm Contact Ratings
2-wire: n/a
4-wire: 0.5 A @ ꢀ0V AC/DC
Smoke detector shall be a System Sensor i3 Series model number_______,
listed to Underwriters Laboratories UL 268 for Fire Protection Signaling
Systems. The detector shall be a combination photoelectric/thermal
equipped with a sounder (model 2WTA-B, 4WTA-B), a Form C relay (model
2WTR-B), a combination sounder/relay (model 4WTAR-B) or an isolated
thermal/sounder/relay (model 4WITAR-B). The detector shall include a
mounting base for mounting to ꢀ½-inch and 4-inch octagonal, single gang,
and 4-inch square back boxes with a plaster ring, or direct mount to the
ceiling using drywall anchors. Wiring connections shall be made by means
of SEMS screws. The detector shall allow pre-wiring of the base and the
head shall be a plug-in type. The detector shall have a nominal sensitivity
of 2.5% per foot nominal as measured in the UL smoke box. The detector
shall be capable of automatically adjusting its sensitivity by means of drift
compensation and smoothing algorithms. The detector shall provide dual
color LED indication which blinks to indicate power-up, normal standby, out
of sensitivity, alarm, and freeze trouble conditions. When used in conjunction
with the 2W-MOD2 module, 2-wire models shall include a maintenance
signal to indicate the need for maintenance at the alarm control panel, and
shall provide a loop testing capability to verify the circuit without testing each
detector individually. When used in conjunction with the RRS-MOD module,
all iꢀ sounder models on a loop shall sound when one alarms, all shall be
synchronized, and all sounders may be silenced from the panel.
Form C Contact Ratings
2A @ ꢀ0V AC/DC
Physical Specifications
Operating Temperature
Range
ꢀ2°F–100° F (0°C–ꢀ7.8° C)
Operating Humidity
Range
0 to 95% RH non-condensing
Thermal Sensor
Freeze Trouble
Sensitivity
1ꢀ5° F (57.2° C) fixed
41° F (5° C)
2.5%/ft. nominal
14–22 AWG
Input Terminals
Dimensions (including
base)
5.ꢀ inches (1ꢀ4 mm) diameter, 2.0 inches (51
mm) height
Approximate Weight
7.1 oz. (200 grams)
Sound Pressure Output
85 dBA (models 2WTA-B, 4WTA-B, 4WTAR-B,
and 4WITAR-B only)
Mounting
ꢀ½-inch octagonal back box, 4-inch octagonal
back box, Single gang back box, 4-inch square
back box with a plaster ring, Direct mount to
ceiling
Ordering Information
Model
Thermal
Wiring
Alarm Current
Model
Description
2WTA-B
Yes
2-wire
1ꢀ0 mA max. limited by
control panel
RRS-MOD
2W-MOD2
SENS-RDR
RT
Reversing relay/synchronization module
2-wire loop test/maintenance module
Sensitivity reader
2WTR-B
Yes
2-wire
1ꢀ0 mA max. limited by
control panel
Removal/replacement tool
Retrofit adapter bracket
4WTA-B
4WTR-B
4WTAR-B
4WITAR-B
Yes
Yes
Yes
Yes
4-wire
4-wire
4-wire
4-wire
ꢀ5 mA
ꢀ5 mA
50 mA
50 mA
A77-AB2
©2006 System Sensor.
ꢀ825 Ohio Avenue • St. Charles, IL 60174
Phone: 800-SENSOR2 • Fax: 6ꢀ0-ꢀ77-6495
Product specifications subject to change without notice. Visit systemsensor.com for
current product information, including the latest version of this data sheet.
A05-0ꢀ48-00ꢀ • 7/06 • #1676
