D400-03-00
1
I56-287-02
2400AT and 2400AIT Direct Wire
Photoelectronic with Fixed Heat
Smoke Detectors
INSTALLATION AND MAINTENANCE INSTRUCTIONS
A Division of Pittway
3825 Ohio Avenue, St. Charles, Illinois 60174
1-800-SENSOR2, FAX: 630-377-6495
Specifications
Size: Diameter:
5.5 inches (140 mm)
Height:
3.19 inches (81 mm); add 0.5 inches (13 mm) for thermal units
Weight:
0.7 lb. (310 g)
Air Velocity:
3000 ft/min (15 M/s)
Operating Temperature:
0
°
C to 38
°
C (0
°
to 100
°
F)
Operating Humidity:
10% to 93% Relative Humidity, noncondensing
Visual Indicator:
Solid State LED
Latching Alarm:
Reset by Momentary Power Interruption
Audible Signal:
85dBA minimum interrupted tone when in alarm or supply voltage polarity is reversed
Fixed Temperature Thermal:
135
°
F (57
°
C)
Electrical Ratings
System Voltage:
24 VDC
Maximum Ripple Voltage:
4 Volts peak-to-peak
Start-up Capacitance:
.02
µ
F Maximum
Start-up Time:
36 Sec. Maximum
Voltage Limits:
10 – 32 VDC
Current Limits
Standby:
120
µ
A Maximum; 100
µ
A Nominal
Alarm Current:
15mA at 10V; 67mA at 32V; 48mA at 24V
Reversed Supply:
5mA at 10V; 19mA at 32V; 15mA at 24V (Detector not in Alarm)
Alarm Impedance:
666 ohms Maximum; 478 ohms Minimum
Alarm Signal:
15mA Minimum in Alarm
Before Installing
Please thoroughly read the System Sensor manual I56-407-
XX,
Guide for Proper Use of System Smoke Detectors
. This
manual provides detailed information on detector spacing,
placement, zoning, wiring, and special applications. It is
available at no charge from System Sensor. (For installa-
tions in Canada refer to CAN/ULC4-S524,
Standard for the
Installation of Fire Alarm Systems
and CEC Part 1, Sec. 32.)
General Description
System Sensor 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 mini-
mizing the effects of ambient light.
These detectors also provide restorable, 135
°
F fixed-tem-
perature heat detection. The 2400AT heat detection unit is
integrated with the photoelectronic sensor while the
2400AIT’s heat detection unit is isolated from the photo-
electronic smoke sensor 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.
An LED on each detector lights to provide a local alarm in-
dication and will remain on until the supply polarity is re-
versed. 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.
Mounting
Each 2400 Series detector is supplied with a mounting
bracket kit to permit mounting in either of two ways:
1. Directly to a 3- or 4-inch octagonal, 1
1
/
2
-inch deep elec-
trical box (See Figures 1 and 2).
2. To a 4-inch square electrical box by using a plaster ring
with the mounting bracket kit supplied.
Spacing
NFPA 72E defines the spacing requirements for smoke de-
tectors. Typically, this is 30 feet when the detectors are in-
stalled on a smooth ceiling. However, ALL installations
must comply with NFPA 72E and/or special requirements
of the authority having jurisdiction.
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