Tamper-Resistant Feature; General Description; Mounting; Wiring Installation Guidelines - System Sensor 2112ж 24ATR Installation And Maintenance Instructions

Figure 2. Surface mounting of 2112/24ATR smoke
1
detector on 3 / -inch and 4-inch octagonal box:
2
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

General Description

Model 2112/24ATR is a 4-wire photoelectronic smoke de-
tector that uses a state-of-the-art optical sensing chamber.
This detector also provides restorable, 135˚F fixed-tem-
perature heat detection. The units have a heat detection
unit that is integrated with the photoelectronic sensor.
In addition, a piezoelectric horn in each detector produces
an interrupted, 85 dBA tone when the individual detector
alarms or when the supply voltage polarity is reversed.
NOTE: In order for all detectors on a loop to sound when
the panel alarms, the panel must reverse the supply volt-
age polarity to that loop upon alarm. For panels that do
not reverse the polarity during alarm, a reversing relay,
such as Systems Sensor's RR-2, must be used. The RR-2
is designed to allow all the detectors in the same loop to
sound when one of the detectors goes into alarm. Some
panels may require the use of programmable outputs.
Refer to System Sensor literature for further information
on the RR-2.
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 range, the status LED blinks every ten seconds. The
LED also latches on in alarm.
If the LED stops blinking, the unit should be removed for
maintenance and inspection.
Figure 3. 2112/24ATR smoke detector mounting bracket:
D200-84-00
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
A78-2563-03
TAMPER SLOT
(DEPRESS TAB TO
REMOVE DETECTOR)
ALIGNMENT
ARROWS

Mounting

Each 2112/24ATR 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.
4. Directly to the ceiling using drywall anchors, if
permitted by local codes and/or the authority having
jurisdiction.

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 screw-
driver to depress the tamper-resistant tab, located in the
slot on the mounting bracket, and turn the detector coun-
terclockwise.

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.
TAMPER RESISTANT TAB
(CUT OFF SMALL TAB TO
ACTIVATE TAMPER-RESIST
FEATURE)
2
A78-2333-01
I56-1240-02R