4 Conventional Products—2400AT and 2400AIT Direct 2-Wire Smoke Detector
!
CAUTION: Equipment hazard. Do not use in potentially
explosive atmospheres. Do not leave unused
wires exposed.
The 2400AT and 2400AIT photoelectronic smoke detectors, listed to
UL 268, provide open area protection and are intended for use with
UL Listed, compatible, 2-wire control panels. The sensor in this detector
operates on the light scattering principle and features a unique photo-optic
sensing chamber that optimizes smoke entry while minimizing the effects
of ambient light.
These detectors also provide restorable, 135°F fixed-temperature heat
detection. The 2400AT heat detection unit is integrated with the
photoelectronic detector; in contrast, the 2400AIT’s heat detection unit is
isolated from the photoelectronic smoke detector and can be monitored
separately. In addition, a piezoelectric horn in each detector produces an
interrupted, 85 dBA tone when the individual detector alarms or when the
supply voltage polarity is reversed.
A Light Emitting Diode (LED) on each detector lights to provide a local
alarm indication. When the control panel receives the alarm signal, the
supply polarity is reversed on the system to sound all the devices. Once
the signal circuit is deactivated, the polarity is reset to the original state.
A screw terminal is provided for a remote LED annunciator optional
accessory (RA400Z). These detectors also have the latching feature.
The alarm can be reset only by momentary power interruption.
Table 1: 2400 Series Direct Wire Smoke Detectors
Model
Control
Description
Operating
Current Consumption
Panel
Voltage
Standby
(Min)
Alarm
(Max)
2400
2-wire
Photo Detector
12/24 VDC
120 µA
—
2400TH
2-wire
Photo Detector with Fixed
Heat Sensor
12/24 VDC
120 µA
—
2400AT
2-wire
Photo Detector with Fixed
Heat Sensor and Horn
24 VDC
120 µA
67 mA
2400AIT
2-wire
Photo Detector with
Isolated Heat Sensor
24 VDC
120 µA
67 mA
2412AT
4-wire
Photo Detector with Fixed
Heat Sensor and Horn
24 VDC
120 µA
51 mA
2424AT
4-wire
Photo Detector with Fixed
Heat Sensor and Horn
24 VDC
120 µA
43 mA
2424AIT
4-wire
Photo Detector with
Isolated Heat Sensor and
Horn
24 VDC
120 µA
43 mA
General
Description
