System Sensor 2400AT and 2400AIT Direct Wire - Manual (Page 2)

D400-03-00 2 I56-287-02
Installation Wiring Guidelines
All wiring must comply with the National Electrical Code
and the applicable local codes, and any special require-
ments of the authority having jurisdiction, using the proper
wire gauges. The conductors used to connect smoke detec-
tors to control panels and accessory devices should be
color-coded to reduce the likelihood of wiring errors. Im-
proper connections can prevent a system from responding
properly in the event of a fire.
For signal wiring (wiring between interconnected detec-
tors), wiring no smaller than AWG 18 is recommended. The
clamping plates in the base can accept wire sizes up to
AWG 12. For best system performance, the power (+and –)
loop wires should be twisted pair and installed in separate
grounded conduit or shielded cable to protect the loop from
extraneous electrical interference. If a cable shield is pro-
vided, the shield connection to and from the detector must
be made continuous by using wire nuts, crimping, or sol-
dering, as appropriate for a reliable connection.
Wire connections are made by stripping about 3/8” insula-
tion from the end of the wire, sliding the bare end of the
wire under the clamping plate, and tightening the clamping
plate screw. Do NOT loop the wire under the terminals.
System Sensor smoke detectors are marked with a compat-
ibility identifier located as the last digit of a five-digit code
stamped on the back of the product. Connect detectors only
to compatible control units as indicated in System Sensor’s
compatibility chart. This chart contains a current list of UL-
listed control units and detector combinations and is avail-
able from System Sensor upon request.
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 remodeling or heavy
construction.
Tamper-resistance Feature
The Tamper Resistant Tab, in the detector mounting
bracket, can make the detector tamper-resistant by making
it necessary to use a pocket screwdriver, or similar tool, to
detach the detector from the bracket.
To make the detector tamper-resistant, use needle-nose pli-
ers to break the smaller tab at the scribed line on the
Tamper Resistant Tab. Figure 2 shows the location of this
tab on the detector mounting bracket.
To remove a detector from the bracket after it has been
made tamper-resistant, use a pocket screwdriver, or other
similar tool, to depress the Tamper Resistant Tab, in the slot
on the mounting bracket, and rotate the detector counter-
clockwise.
Testing
NOTE: Before testing, notify the proper authorities that the
smoke detector system is undergoing maintenance
and, therefore, the system will be temporarily out
of service. Disable the zone or system undergoing
maintenance to prevent unwanted alarms.
Figure 1. Flush mounting of detector on 4-inch
octagonal box:
TAMPER
RESISTANT
TAB
TO MAKE DETECTOR TAMPER RESISTANT,
BREAK OFF TAB EXTENSION
AT SCRIBED LINE
Figure 3. Wiring diagram for 2400AT detector with two-wire control panel:
Figure 2. Detector mounting bracket:
A78-534-00 A78-1394-00