D200-83-00
2
I56-1239-01
Figure 2. Surface mounting of 2112/24R and
2112/24TR smoke detector on 3
1
/
2
-inch and 4-inch
octagonal box:
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A78-2563-01
Figure 3. 2112/24R and 2112/24TR smoke detector mounting bracket:
A78-2333-04
If the LED stops blinking, the unit should be removed for
maintenance and inspection.
Mounting
Each 2112/24R and 2112/24TR 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
tool. To make the detector tamper-resistant, remove the
smaller tab by breaking it at the scribed line on the tamper
resistant tab on the detector mounting bracket (see Figure
3), 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, lo-
cated in the slot on the mounting bracket, and turn the de-
tector counterclockwise.
Wiring Installation Guidelines
All wiring must be installed in compliance with the Na-
tional Electrical Code, applicable local codes, and any spe-
cial 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 reduce the likelihood of
wiring errors. Improper connections can prevent a system
from responding properly in the event of a fire.
The screw terminal block accepts 14 – 22 gauge wire. For
best system performance, all wiring should be installed in
separate grounded conduit. Do not mix fire system wiring
in the same conduit as any other electrical wiring. Twisted
pair may be used to provide additional protection against
electrical interference.
Smoke detectors and alarm system control panels have
specifications for allowable loop resistance. Consult the
control panel specifications for the total loop resistance al-
lowed for the control panel being used before wiring the
detector loops.
Before Installing
Please thoroughly read the System Sensor manual I56-407,
Guide for Proper Use of System Smoke Detectors, which pro-
vides 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 shall 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
Models 2112/24R and 2112/24TR are 4-wire photoelectronic
smoke detectors that use a state-of-the-art optical sensing
chamber. The 2112/24TR also provides restorable, 135˚F
fixed-temperature heat detection. The 2112/24TR heat-de-
tection unit is integrated with the photoelectronic sensor.
Installation of this detector 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 within the listed sensi-
tivity ranges, the status LED blinks every ten seconds. The
LED also latches on in alarm.
TAMPER SLOT
(DEPRESS TAB TO
REMOVE DETECTOR)
TAMPER RESISTANT TAB
(CUT OFF SMALL TAB TO
ACTIVATE TAMPER-RESIST
FEATURE)
ALIGNMENT
ARROWS
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