D200-62-00 1 I56-932-07
2112/24D(A) and 2112/24TD(A)
Photoelectronic Smoke Detectors
INSTALLATION AND MAINTENANCE INSTRUCTIONS
A Division of Pittway
3825 Ohio Avenue, St. Charles, Illinois 60174
1-800-SENSOR2, FAX: 630-377-6495
Before Installing
Please thoroughly read the System Sensor manual I56-407,
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-M91,
Standard for the Installation of Fire Alarm Systems
, and
CEC Part 1, sec. 32.)
NOTICE:
This manual should be left with the owner/user
of this equipment.
IMPORTANT:
This detector must be tested and maintained
following NFPA 72 requirements. The detector should be
cleaned at least once a year.
General Description
Model 2112/24D(A) is a 4-wire photoelectronic smoke de-
tector that uses a state-of-the-art optical sensing chamber.
This detector is designed to provide open area protection.
Model 2112/24TD(A) features a restoreable, built-in, fixed-
temperature (135°F) thermal detector.
Installation of these detectors is simplified by the use of a
mounting bracket and a plug-in screw terminal block that
can be prewired to the system, allowing the detector to be
easily installed or removed for cleaning. The detector’s
sensitivity can be tested in place using the MOD400R Test
Module.
An LED on the detector provides a local visual indication of
the detector’s status. If power is applied to the detector, and
it is functioning normally in standby, the status LED blinks
every ten seconds. The LED also latches on in alarm.
Models 2112/24D(A) and 2112/24TD(A) feature a visual
indication that maintenance is required – if the sensing
chamber drifts out of its sensitivity limits, the LED ceases
to blink.
Mounting
Each 2112/24D(A) and 2112/24TD(A) detector is supplied
with a mounting bracket that permits the detector to be
mounted:
1. To a single gang box, or
2. Directly to a 3
1
/
2
-inch or 4-inch octagonal box, or
3. To a 4 inch square electrical box by using a plaster ring.
Tamper-resistant Feature
This detector includes a tamper-resistant feature that pre-
vents its removal from the bracket without the use of a
Figure 1. Wiring diagram for the 2112/24D(A) and 2112/24TD(A) detectors:
OPTIONAL CLASS A WIRING
EOL RESISTOR
SPECIFIED BY
PANEL
MANUFACTURER
EOL POWER
SUPERVISION
RELAY (SHOWN
ENERGIZED)
A77-716 12/24V
POWER
TO
DETECTORS
UL LISTED
CONTROL
PANEL
INITIATING
LOOP
+
–
+
–
P
W
R
+
+
–
+
–
+
–
N.O.
C
P
W
R
+
+
–
N.O.
C
: Observe polarity in power and initiating loops when wiring.
NOTE
A78-2336-03
IMPORTANT: OBSERVE POLARITY
This detector requires that you observe polarity when wiring. If wiring polarity is not observed on the
initiating loop, the unit will send an alarm signal to the control panel to signify incorrect wiring.
firealarmresources.com
