D200-63-00
1
I56-931-06
1112/24D Ionization Smoke Detector
INSTALLATION AND MAINTENANCE INSTRUCTIONS
3825 Ohio Avenue, St. Charles, Illinois 60174
1-800-SENSOR2, FAX: 630-377-6495
Before Installing
Please thoroughly read System Sensor Manual I56-407,
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.
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
The 1112/24D is a 4-wire ionization smoke detector that
uses a state-of-the-art sensing chamber. This detector is
designed to provide open area protection.
Installation of this detector is simplified by the use of an
adapter 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
sensitivity can be tested in place using the MOD400R
Test Module.
An LED on the detector provides local visual indication of
the detector status. If power is applied to the detector, and
it is functioning normally in standby, the status LED blinks
every five seconds. The LED also latches on in alarm.
The 1112/24D also features visual indication that mainte-
nance is required; if the sensing chamber drifts out of its
sensitivity limits, the LED ceases to blink.
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.
A78-2336-05
OPTIONAL CLASS A WIRING
EOL RESISTOR
SPECIFIED BY
PANEL
MANUFACTURER
EOL POWER
SUPERVISION
RELAY (SHOWN
ENERGIZED)
A77-716B 12/24V
POWER
TO
DETECTORS
UL LISTED
CONTROL
PANEL
INITIATING
LOOP
+
–
+
–
+
+
+
–
–
+
–
N.O.
C
+
+
–
N.O.
C
: Observe polarity in power and initiating loops when wiring.
NOTE
Figure 1. Wiring diagram for the 1112/24D detector:
