INSTALLATION AND MAINTENANCE INSTRUCTIONS
FOR MODEL 2312/24TB
Before installing detectors, please thoroughly read System Sensor Manual I56-407-XX,
Guide for Proper Use of System Smoke
Detectors,
which provides detailed information on detector spacing, placement, zoning, wiring, and special applications. Copies of this
manual are available at no charge from System Sensor.
GENERAL DESCRIPTION:
Model 2312/24TB is a 4-wire combination smoke/heat detector. In addition to photoelectronic smoke detection, two supervised elec-
tronic thermistors provide restorable 135°F fixed temperature heat detection. The installation is simplified by the use of an adaptor
bracket and a plug-in screw terminal block which can be pre-wired to the system allowing the detector to be easily installed or removed
for cleaning. It is designed to provide open area protection, and to be used with UL listed 4-wire control panels. The detector’s sen-
sitivity can be tested in place using the MOD400R field sensitivity test module.
The 2312/24TB is listed to UL 268 and is a latching type system detector. When latched in alarm, the detector must be reset by a
momentary power interruption.
An LED on the detector provides a local indication of the detector’s status. If power is applied to the detector, and the detector is
functioning properly in standby, the status LED will blink every 10 seconds. The detector performs a self-test on its smoke sensing
chamber and internal electronics every 40 seconds. If this test fails, the detector stops blinking the status LED in standby, and the
LED will remain off. In alarm, the LED will be latched on continuously until the detector is reset.
SPECIFICATIONS:
Diameter: 5.5 inches (14 cm)
Height: 2.5 inches (6.4 cm)
Weight: 0.7 lb (310 gm)
Operating Temperature Range: 0° to +38° C (32° to 100° F)
Operating Humidity Range: 10% to 90% Relative Humidity Non-condensing
Latching Alarm: Reset by momentary power interruption.
Test Feature: Recessed test switch.
Maximum Air Velocity: 3000 Ft./Min. (15 Meters/Sec.).
Sensitivity: Nominal 3%/Ft.
Heat Sensor: 135°F Fixed Temperature Electronic Thermistor
ELECTRICAL RATINGS:
System Voltage nominal: 12 or 24 VDC
minimum: 8.5 VDC
maximum: 35 VDC
Maximum Ripple Voltage: 30% of nom. Voltage (peak to peak)
Standby Current: 120
µ
A max.
Alarm Current: 10mA minimum. 50mA maximum.
Reset Voltage: 0.8 VDC minimum
Reset Time: 6 Sec. maximum
Start-up Time: 34 Sec. maximum
(After 60 Sec. Reset)
EOL relay: A77-716B, 12/24 Volt
ALARM INITIATION CONTACT RATINGS:
Resistive or inductive load (60% power factor):
Form A: 2.0A @ 30 VAC/DC
S0175-00
Figure 1. 2312/24TB Smoke/Heat Detector
D300-05-00 I56-431-06
System Sensor, 3825 Ohio Avenue, St. Charles, Illinois 60174, 1-800-SENSOR2, FAX: 708-377-6495
