SYSTEMSENSOR 2424AIT

INSTALLATION AND MAINTENANCE INSTRUCTIONS
2412AT, 2424AT, and 2424AIT
Direct Wire Photoelectronic with
Fixed Heat Smoke Detectors
Specifications
Diameter:
Height, with Thermal:
Weight:
Operating Temperature:
Operating Humidity:
Visual Indicator:
Locking Alarm:
Audible Signal:
Electrical Ratings:
Operating Voltage:
A Division of Pittway
3825 Ohio Avenue, St. Charles, Illinois 60174
1-800-SENSOR2, FAX: 630-377-6495
5.5 inches (14 cm)
3.19 inches (8.1 cm)
0.7 lb. (310 g)
0° to 38° C (32° to 100° F)
10% to 95% Relative Humidity Non-condensing
Solid State LED
Reset by momentary power interruption
85dBA minimum interrupted tone when individual unit is in alarm or when the
supply voltage is reversed.
2412AT
2424AT or 2424AIT
12VDC
24VDC
Full-wave, Unfiltered
Full-wave, Unfiltered
Current
Standby:
120 µA Max.
120 µA Max.
Alarm:
51mA
43mA
(Add 7mA Maximum with RA400Z Remote Annunciator LED)
Reversed Supply:
8mA
15mA
Start-up Time:
36 seconds maximum
Relay Characteristics:
One Form A (SPST-NO) for alarm initiation 1.25A at 30 VAC/DC
minimum tone when the individual detector alarms or
when the supply voltage polarity is reversed.
Before Installing
Please thoroughly read the System Sensor manual I56-407XX, 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. (For installations in Canada refer to CAN\ULCS524, Standard for the Installation of Fire Alarm Systems
and CEC Part 1, Sec. 32.)
An LED on each detector lights to provide a local alarm
indication and will remain on when the supply polarity is
reversed. A screw terminal is provided for a remote LED
annunciator optional accessory (RA400Z). These detectors
are listed to UL268 and are latching type system detectors.
The alarm can be reset only by momentary power
interruption. For testing, these detectors have a test switch
or may be tested by inserting a calibrated test card in a test
slot after removing the detector’s cover.
General Description
System
Sensor
2412AT,
2424AT
and
2424AIT
photoelectronic smoke detectors are designed to provide
open area protection and to be used with UL-listed 4-wire
control panels. The 2412AT operates at 12 VDC and the
2424AT and 2424AIT operate at 24 VDC. The sensor in this
detector operates on the light scattering principle and
features a unique photo-optic sensing chamber that
provides good smoke entry while minimizing the effects of
ambient light. These detectors also provide restorable
135°F fixed-temperature heat detection. The 2412AT and
2424AT heat detection unit is integrated with the
photoelectronic sensor while the 2424AIT’s heat detection
unit is isolated from the photoelectronic smoke sensor and
can be monitored separately. In addition, a piezoelectric
horn in each detector produces an interrupted, 85 dBA
D400-04-00
Each detector contains one Form A (SPST-NO) contact for
connection to an alarm-initiating circuit. Supervision of the
detector power is accomplished by installing a Power
Supervisory End-of-Line Relay Module (A77-716) at the end
of the detector power loop. When power is applied to and
through the detectors, the EOL Power Supervisory Module
is energized. Its relay contacts close and provide a closed
series circuit in the control panel’s alarm-initiating loop. A
power failure or break in the detector power loop deenergizes the EOL Module. The relay contacts open and
trigger a trouble signal at the control panel.
1
I56-288-05
Figure 1. Flush mounting of detector on 4-inch
octagon box:
Figure 2. Detector mounting bracket:
TAMPER
RESISTANT
TAB
A78-1411-00
TO MAKE DETECTOR TAMPER RESISTANT,
BREAK OFF TAB EXTENSION
AT SCRIBED LINE
Mounting Instructions
Each 2400 Series detector unit is supplied with a mounting
bracket kit that permits several mounting techniques:
1. Units may be mounted directly to a 3-inch or 4-inch octagonal,
11/2 inch deep electrical box. (See Figures 1 and 2.)
2. Units may be mounted to a 4-inch square electrical box by
using plaster ring with the supplied mounting bracket kit.
A78-534-00
system and all smoke alarms before the panel gives the
required battery-low signal. When the battery-low signal is
given, the battery should be capable of providing power for
another 7 days, after which the backup battery should have
enough energy left to allow a 4-minute alarm signal to be
given by all connected smoke alarms.
Wiring Installation Guidelines
All wiring must be in compliance with the National
Electrical Code and the applicable local codes, and any
special requirements of the local authority having
jurisdiction. Proper wire gauges should be used. The
conductors used to connect smoke detectors to control
panels and accessory devices should be color-coded to
prevent wiring mistakes. Improper connections can prevent
a system from responding properly in the event of a fire.
For signal wiring (the wiring between interconnected
detectors), wire no smaller than 18 AWG is recommended.
Wire sizes up to 12 AWG may be used. For best system
performance, the power (+and –) loop wires should be
twisted pair and installed in separate grounded conduit or
shielded cable to protect the loop from extraneous electrical
interference. If a cable shield is provided, the shield connection to and from the detector must be continuous by
using wire nuts, crimping, or soldering as appropriate for a
reliable connection.
Wire connections are made by stripping about 3/8" of
insulation from the end of the wire (use strip gauge molded
in base), sliding the bare end of the wire under the
clamping plate, and tightening the clamping plate screw.
Do not loop the wire under the clamping plate.
Tamper-proof Feature
This detector includes a tamper-proof feature that, when
activated, prevents removal of the detector without the use
of a tool. To activate this feature, cut off smaller tab at the
scribe line on tamper-proof tab located on the detector
mounting bracket (see Figure 2). Install the detector. To
remove the detector from the bracket once the tamperproof feature has been activated, depress the tamper-proof
tab located in the slot on the mounting bracket and turn the
detector counterclockwise for removal.
Installation In Australia Only
The installation temperature range for Australia is 5° to
45°C and has been tested per the Australian Standard.
Ignore installation temperatures specified for all other
applications when installing detectors in Australia.
Detectors should be installed by qualified technicians.
Installation of a mains connected power supply unit must
be performed by qualified electricians only. The primary
power will be provided by a panel type system. A rechargeable battery is required as a backup to the external power
supply in case of a mains failure. In standby operation, the
backup battery (fully charged) must be capable of
providing uninterrupted power for at least 7 days to the
Figure 3. Class A or Class B wiring diagram for model 2412AT and 2424AT detectors used with four-wire
control panels:
D400-04-00
2
I56-288-05
Figure 4. Additional wiring needed for the isolated thermal unit of the 2424AIT detector thermal units are
wired to a separate loop:
UL LISTED
TWO OR FOUR
WIRE PANEL
4
4
5
5
SUGGESTED
EOL
RESISTOR
+
INITIATING
LOOP
A78-1392-01
–
3. The detector should not alarm (wait at least 20
seconds).
4. Remove the test card by sliding it clockwise before
removing, then repeat with the ALARM end of test
card.
5. The LED should latch on within 20 seconds indicating
alarm and annunciating the panel.
6. Put the cover back by gently rotating it clockwise
until it locks in place.
C. Test Module (System Sensor Model No. MOD400R)
The MOD400R is used with an analog or digital
voltmeter to check the detector sensitivity as described
in the test module’s manual.
D. Aerosol Generator (GEMINI 501)
Set the generator to represent 4%/ft. to 5%/ft.
obscuration as described in the Gemini 501 manual.
Using the bowl shaped applicator, apply aerosol until
unit alarms.
E. Direct Heat Method (Hair dryer of 1000–1500 watts)
Direct the heat toward the bi-metallic collector. Hold the
heat source about 12 inches from the detector in order to
avoid damage to the plastic. When the heat rises to
greater than 135° F, the detector should latch in alarm.
The detector will reset only after it has had sufficient
time to cool and the power source has been momentarily
interrupted.
Notify the proper authorities tht the system is back on line.
CAUTION
Dust covers are an effective way to limit the entry of dust
into smoke detector sensing chambers. However, they may
not completely prevent airborne dust particles from
entering the detector. Therefore, System Sensor recommends the removal of detectors before beginning
construction or other dust producing activity. Be sure to
remove dust covers from any sensors that were left in place
during construction as part of returning the system to
service.
TESTING
NOTE: Before testing, notify the proper authorities that
the smoke detector system is undergoing maintenance, and therefore will temporarily be out of
service. Disable the zone or system undergoing
maintenance to prevent unwanted alarms.
Detectors must be tested after installation and periodic
maintenance. The 2412AT, 2424AT or 2424AIT may be
tested in the following ways:
NOTE: Before testing the detector check for the presence
of the flashing LED. If it does not flash, power has
been lost to the detector (check the wiring), or it is
defective (return for repair, see Warranty
information).
A. Recessed Test Switch
1. Push and hold the recessed test switch with a .1 inch
maximum diameter tool.
2. The LED should latch within 5 seconds indicating
alarm and annunciating the panel. The horn should
also sound.
B. Calibrated Test Card (System Sensor No. R59-18-00)
1. Remove the detector cover by placing a small bladed
screwdriver in the side slot of the detector cover,
twisting it slightly until the cover can be turned
counterclockwise for removal.
2. Insert the NO ALARM end of the test card fully into
the test slot (see Figure 6) then slide it
counterclockwise until it stops.
D400-04-00
Figure 5. Bottom and side views showing position of
test switch:
LED
RECESSED TEST
SWITCH
TEST MODULE
SOCKET
PUSH RECESSED SWITCH WITH
A .1" MAX. DIAMETER TOOL
1410-00
3
I56-288-05
Detectors that fail these tests should be cleaned as
described under MAINTENANCE and retested. If the
detectors still fail these tests they should be returned for
repair.
aligns with the field test socket on the detector. Carefully
push the screen into place, making sure it fits tightly to
the chamber.
6. Replace the cover by gently rotating it clockwise until it
locks in place.
Maintenance
NOTE: Before cleaning, notify the proper authorities that
the smoke detector system is undergoing
maintenance, and will be temporarily out of service. Disable the system undergoing maintenance
to prevent unwanted alarms.
1. Remove the detector cover by placing a small bladed
screwdriver in the side slot of the detector cover,
twisting it slightly until the cover can be turned
counterclockwise for removal.
2. Vacuum the screen carefully without removing it. If
further cleaning is required continue with Step 3,
otherwise skip to Step 6.
3. Remove the screen by pulling it straight out. Vacuum the
inside.
4. Clean the vaned chamber piece by vacuuming out dust
and particles.
5. To replace the screen, orient it so that the arrow on top
Figure 6:
WARNING
The Limitations of Property Protection Smoke Detectors
fast, flaming fires than slow, smoldering fires. Photoelectronic detectors
sense smoldering fires better than flaming fires. Because fires develop in
different ways, and are often unpredictable in their growth, neither type
of detector is always best, and a given detector may not always provide
warning of a fire. In general, detectors cannot be expected to provide
warnings for fires resulting from inadequate fire protection practices,
violent explosions, escaping gas, improper storage of flammable liquids
like cleaning solvents, other safety hazards, or arson. Smoke detectors
used in high air velocity conditions may fail to alarm due to dilution of
smoke densities created by such frequent and rapid air exchanges. Additionally, high air velocity environments may create increased dust contamination, demanding more frequent maintenance.
Smoke detectors are designed to activate and initiate emergency action,
but will do so only when used in conjunction with other equipment.
These detectors are designed for installation in accordance with NFPA
standard 72.
Smoke detectors will not work without power. AC or DC powered
smoke detectors will not work if the power supply is cut off for any
reason.
Smoke detectors will not sense fires which start where smoke does
not reach the detectors. Smoke from fires in chimneys, in walls, on
roofs, or on the other side of closed doors may not reach the smoke detector and alarm it.
Smoke detectors cannot last forever. Smoke detectors contain electronic parts. Even though detectors are made to last over 10 years, any of
these parts could fail at any time. Therefore, test your smoke detector
system per NFPA 72E at least semiannually. Clean and take care of your
smoke detectors regularly. Taking care of the fire detection system you
have installed will measurably reduce your product liability risks.
A detector may not detect a fire developing on another level of a
building. For this reason, detectors should be located on every level of a
building.
Smoke detectors have sensing limitations, too. Ionization detectors offer broad range fire-sensing capability, but they are better at detecting
Three-Year Limited Warranty
ment, RA #__________, 3825 Ohio Avenue, St. Charles, IL 60174. Please
include a note describing the malfunction and suspected cause of failure.
The Company shall not be obligated to repair or replace units which are
found to be defective because of damage, unreasonable use, modifications, or alterations occurring after the date of manufacture. In no case
shall the Company be liable for any consequential or incidental damages
for breach of this or any other Warranty, expressed or implied whatsoever,
even if the loss or damage is caused by the Company’s negligence or fault.
Some states do not allow the exclusion or limitation of incidental or consequential damages, so the above limitation or exclusion may not apply to
you. This Warranty gives you specific legal rights, and you may also have
other rights which vary from state to state.
System Sensor warrants its enclosed smoke detector to be free from defects in materials and workmanship under normal use and service for a
period of three years from date of manufacture. System Sensor makes no
other express warranty for this smoke detector. No agent, representative,
dealer, or employee of the Company has the authority to increase or alter
the obligations or limitations of this Warranty. The Company’s obligation
of this Warranty shall be limited to the repair or replacement of any part of
the smoke detector which is found to be defective in materials or workmanship under normal use and service during the three year period commencing with the date of manufacture. After phoning System Sensor’s toll
free number 800-SENSOR2 (736-7672) for a Return Authorization number,
send defective units postage prepaid to: System Sensor, Repair DepartD400-04-00
4
I56-288-05
© System Sensor 1996