System Sensor 2412 User manual

D400-06-00 1 I56-286-03
2412, 2412TH, 2424, and 2424TH
Direct Wire Photoelectronic
Smoke Detectors
INSTALLATION AND MAINTENANCE INSTRUCTIONS
A Division of Pittway
3825 Ohio Avenue, St. Charles, Illinois 60174
1-800-SENSOR2, FAX: [phone]
Before Installing
Please thoroughly read the System Sensor manual I56-407-
XX, Guide for Proper Use of System Smoke Detectors, which
provides detailed information on detector spacing, place-
ment, zoning, wiring, and special applications. Copies of
this manual are available at no charge from System Sensor.
(For installation in Canada, refer to CAN/ULC-S524, Stan-
dard for the Installation of Fire Alarm Systems and CEC
Part 1, Sec. 32.)
General Description
System Sensor 2412 and 2424 photoelectronic smoke detec-
tors utilize state-of-the-art, optical sensing chambers. These
detectors are designed to provide open area protection, and to
be used with compatible UL-listed 4-wire control panels only.
The 2412 applies to 12 volt panels and operates at 12VDC,
and the 2424 applies to 24 volt panels and operates at
24VDC. Operation and sensitivity can be tested in place.
Models 2412TH and 2424TH have the same specifications as
models 2412 and 2424, but in addition feature a built-in fixed
Specifications
Diameter: 5.5 inches (14 cm)
Height: 3.19 inches (81 mm); Add 0.5 inches (1.3 cm) for thermal units
Weight: 0.7 lb (310 g)
Operating Temperature Range: 2412 and 2424 — 0°to +49°C (32°to 120°F)
2412TH and 2424TH — 0°to +38°C (32°to 100°F)
Operating Humidity Range: 10% to 93% Relative Humidity
Maximum Air Velocity: 3000 Ft./Min. (15 M/S)
Latching Alarm: Reset by momentary power interruption.
Electrical Ratings 2412 2424
System Voltage: 12 24 DC (4V Maximum Ripple)
Supply Voltage: 11.3 20 VDC Minimum
17 29 VDC Maximum
Reset Voltage: .73 .8 VDC Minimum
Standby Current: 120 120 µ A Maximum
Alarm Currents: 35 21.3 mA Minimum
77 40.6 mA Maximum
The alarm and auxiliary relay operate within the specified voltage ratings.
Start-up Time: 34 34 S Maximum
EOL Relay: A77-716 A77-716
Reset Time: 0.3 0.3
Relay Contacts – resistive or inductive (60% power factor) load:
Form A: 2.0A @ 30VAC/DC
Form C:* 0.6A @ 110VDC; 2.0A @ 30VDC
1.0A @ 125VAC; 2.0A @ 30VAC
(*For Canadian installations, relay contact rating is 2.0A @ 30VAC/DC)
temperature (135°F) thermal detection unit.
An LED on each detector lights to provide a local alarm indi-
cation. It flashes every ten seconds indicating that power is
applied to the detector. The LED lights continuously in alarm.
These detectors also have the latching alarm feature that re-
sets only by a momentary power interruption.
Each detector contains one set of Form A contacts for connec-
tion to the alarm-initiating circuit, and one set of Form C aux-
iliary contacts. Supervision of detector power is
accomplished by installing a Power Supervisory End-of-Line
Relay Module (A77-716 Series) at the end of the detector
power loop. When power is applied to and through the detec-
tors, the EOL Power Supervisory Module is energized. Its re-
lay contacts close and provide a closed series circuit in the
control panel’s alarm-initiating loop. A power failure or a
break in the detector power loop de-energizes the EOL Mod-
ule. The relay contacts open and trigger a trouble signal at the
control panel.

D400-06-00 2 I56-286-03
Mounting
Each 2412 and 2424 detector is supplied with a mounting
bracket kit that permits the detector to be mounted:
1. Directly to a 3-1/2 inch or 4 inch octagonal, 1-1/2 inch
deep electrical box, (see Figure 1) or
2. To a 4 inch square electrical box by using a plaster ring
with the supplied mounting bracket kit.
Installation Wiring Guidelines
NOTE: Refer to releasing device manufacturer’s installa-
tion instruction for proper connections.
All wiring must be installed in compliance with the Na-
tional Electrical Code and all applicable local codes and
any special requirements of the authority having jurisdic-
tion, using the proper wire size. The conductors used to
connect smoke detectors to control panels and accessory
devices should be color-coded to reduce the likelihood of
wiring errors. Improper connections can prevent a system
from responding properly in the event of a fire.
For signal wiring (the wiring between interconnected de-
tectors), it is recommended that the wire be no smaller
than AWG 18. However, the screws and clamping plate, in
the base, can accommodate wire sizes up to AWG 12. The
use of twisted pair wiring for the power (+ and –) loop is
recommended to minimize the effects of electrical interfer-
ence.
Smoke detectors and alarm system control panels have
specifications for allowable loop resistance. Consult the
control panel manufacturer’s specifications for the total
loop resistance allowed for the particular model control
panel being used before wiring the detector loops.
NOTE: For system supervision – for terminals 1, 2, 7, and
8, do not use looped wire under terminals. Break
wire run to provide system supervision of connec-
tions.
NOTE: Contacts are shown in stand-by mode and will
transfer in alarm condition.
Wire connections are made by stripping about 3/8 inch of
insulation from the end of the wire, sliding the bare end of
the wire under the clamping plate, and tightening the
clamping plate screw.
Tamper-resistance Feature
This detector includes a tamper-resistant feature that pre-
vents removal of the detector without the use of a tool. To
make the detector tamper-resistant, break off the smaller
tab at the scribed line on the Tamper Resistant Tab, on the
detector mounting bracket (see Figure 2), then install the
detector. To remove the detector from the bracket once it
has been made tamper-resistant, use a small screwdriver to
depress the tamper-resistant tab located in the slot on the
mounting bracket and turn the detector counterclockwise
for removal.
Installation
WARNING
Remove power from initiating-device circuits before install-
ing detectors.
1. Wire detector per installation guidelines.
TAMPER
RESISTANT
TAB
TO MAKE DETECTOR TAMPER RESISTANT,
BREAK OFF TAB EXTENSION
AT SCRIBED LINE
Figure 1. Flush mounting of 2412/2424 smoke
detector on 3-1/2 inch and 4-inch octagonal box:
Figure 2. 2412/2424 smoke detector mounting
bracket:
COMMON
N/O
N/C
AUXILIARY
CONTACTS
FORM C
456
78
21
+-
POWER
ALARM
CONTACTS
FORM A
N/O
A78-1811-00 A78-1554-01
COMMON
N/O
N/C
(OPTIONAL)
RELEASING
DEVICE
456
78
21
+-
COMMON
N/O
N/C
(OPTIONAL)
RELEASING
DEVICE
456
78
21
+-
EOL
POWER
SUPERVISION
RELAY
MODULE
SUGGESTED
EOL
RESISTOR
CLASS A OPTIONAL WIRING
INITIATING
LOOP
POWER
TO
DETECTORS
UL LISTED
CONTROL
PANEL
+
-
+
-
Figure 3. Wiring diagram for 2412/2424 series smoke detector used with 4-wire control panel:

D400-06-00 3 I56-286-03
2. Line up arrows on the detector with arrows on the
mounting bracket.
3. Turn the detector clockwise until the detector clicks into
place.
4. After all detectors have been installed, apply power to
the control unit.
5. Test the detector as described under TESTING.
6. Reset the detector at the System Control Panel.
7. Notify the proper authorities the system is in operation.
CAUTION
Dust covers provide limited protection against airborne
dust particles during shipping. Dust covers MUST be re-
moved before the smoke detectors can sense smoke. Re-
move sensors before beginning heavy remodeling or
construction.
Testing
Before testing, notify the proper authorities that the smoke
detector system is undergoing maintenance, and therefore
the system will temporarily be out of service. Disable the
zone or system undergoing maintenance to prevent un-
wanted alarms.
Before testing the detector, look 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 re-
pair).
Detectors must be tested after installation and following
periodic maintenance. The 2412 and 2424 may be tested as
follows:
A. Recessed Test Switch
1. A test switch is located on the detector housing (see
Figure 4).
2. Push and hold the recessed test switch with a 0.1 inch
maximum diameter tool.
3. The detector’s LED should light within 5 seconds.
B. Calibrated Test Card (Model R59-18-00)
TEST MODULE
SOCKET
LED
RECESSED TEST
SWITCH
PUSH RECESSED SWITCH WITH
A .1" MAX. DIAMETER TOOL
Figure 4. Top and side views showing position of recessed test switch:
A78-1393-00
1. Remove the detector cover by placing a small-bladed
screwdriver in the side slot of the detector cover,
twisting slightly until the cover can be turned coun-
terclockwise for removal.
2. Insert the NO ALARM end of the test card fully into
the test slot (see Figure 5), then slide it counterclock-
wise until it stops.
3. The detector should not alarm after 20 seconds.
4. Remove the test card by sliding it clockwise before re-
moving, then insert the ALARM end.
5. The LED should latch on within 20 seconds, indicat-
ing alarm and annunciating the panel.
6. Put the cover back by gently rotating it clockwise un-
til it locks in place.
C. Test Module (System Sensor Model No. MOD400R)
The MOD400R is used with an analog or digital voltme-
ter to check the detector sensitivity as described in the
MOD400R manual.
D. Aerosol Generator (Gemini 501)
Set the generator to represent 4%/Ft. to 5%/Ft. obscura-
tion as described in the Gemini 501 manual. Using the
bowl shaped applicator, apply aerosol until unit alarms.
Detectors that fail these tests should be cleaned as de-
scribed under MAINTENANCE and retested. If the detec-
tors still fail these tests, they should be returned for
repair.
E. Direct Heat Test (Models 2412TH & 2424TH only)
To test the bi-metallic thermal collector on the Models
2412TH and 2424TH, use a low powered heat gun or
blow dryer, aiming the heat source across the detector.
Hold the heat source about 12 inches (30 cm) from the
detector to avoid damaging the plastic. When the heat
rises to greater than 135°F, the detector will latch in
alarm. After the test, the bi-metallic collector will self-re-
store.
Notify the proper authorities that the system is back on
line when tests are complete.

D400-06-00 4 I56-286-03
© System Sensor 1996
Three-Year Limited Warranty
System Sensor warrants its enclosed smoke detector to be free from de-
fects 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 work-
manship under normal use and service during the three year period com-
mencing 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 Depart-
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, modifica-
tions, 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 conse-
quential 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.
This smoke detector is designed to activate and initiate emergency ac-
tion, but will do so only when it is used in conjunction with an authorized
fire alarm system. This detector must be installed 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.
Smoke detectors will not sense fires which start where smoke does not
reach the detectors. Smoldering fires typically do not generate a lot of
heat which is needed to drive the smoke up to the ceiling where the
smoke detector is usually located. For this reason, there may be large de-
lays in detecting a smoldering fire with either an ionization type detector
or a photoelectric type detector. Either one of them may alarm only after
flaming has initiated which will generate the heat needed to drive the
smoke to the ceiling.
Smoke from fires in chimneys, in walls, on roofs or on the other side of a
closed door(s) may not reach the smoke detector and alarm it. A detector
cannot detect a fire developing on another level of a building quickly or at
all. For these reasons, detectors shall be located on every level and in
every bedroom within a building.
Smoke detectors have sensing limitations, too. Ionization detectors and
photoelectric detectors are required to pass fire tests of the flaming and
smoldering type. This is to ensure that both can detect a wide range of
types of fires. Ionization detectors offer a broad range of fire sensing capa-
bility but they are somewhat better at detecting fast flaming fires than
slow smoldering fires. Photoelectric detectors sense smoldering fires better
than flaming fires which have little, if any, visible smoke. Because fires de-
velop in different ways and are often unpredictable in their growth, nei-
ther type of detector is always best, and a given detector may not always
provide early warning of a specific type of fire.
In general, detectors cannot be expected to provide warnings for fires re-
sulting from inadequate fire protection practices, violent explosions, es-
caping gases which ignite, improper storage of flammable liquids like
cleaning solvents which ignite, other similar safety hazards, arson, smok-
ing in bed, children playing with matches or lighters, etc. Smoke detectors
used in high air velocity conditions may have a delay in alarm due to dilu-
tion of smoke densities created by frequent and rapid air exchanges. Addi-
tionally, high air velocity environments may create increased dust
contamination, demanding more frequent maintenance.
Smoke detectors cannot last forever. Smoke detectors contain electronic
parts. Even though smoke detectors are made to last over 10 years, any
part can fail at any time. Therefore, smoke detectors shall be replaced after
being in service for 10 years. The smoke detector system that this detector
is used in must be tested regularly per NFPA 72. This smoke detector
should be cleaned regularly per NFPA 72 or at least once a year.
WARNING
The Limitations of Property Protection Smoke Detectors
REMOVABLE COVER
CLEANABLE SCREEN
P/N RS24 (W/O THERMAL)
RS24T (W/THERMAL)
TEST SLOT
VANED CHAMBER
A78-1390-00
Maintenance
NOTE: Before removing the detector cover, notify the
proper authorities that the smoke detector system
is undergoing maintenance, and therefore the sys-
tem will be temporarily out of service. Disable the
zone or 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 fur-
ther cleaning is required, continue with step 3, other-
wise skip to step 6.
3. Remove the screen by pulling it straight out (see Figure
5). Vacuum the inside.
4. Clean the vaned chamber piece by vacuuming or blow-
ing out dust and particles.
5. To replace the screen, orient it so that the arrow on top
aligns with the test module socket of the detector. Care-
fully push the screen onto the base, making sure it fits
tightly to the chamber.
Figure 5. Removal of cover and screen for cleaning:
6. Replace the cover by gently rotating it clockwise until it
locks in place.
7. Notify the proper authorities the system is back on line.