D400-08-00 REV#-002
2
I56-007-000
Mounting
Each 42A and 424A detector is supplied with a mount-
ing bracket kit that permits the detector to be mounted:
. Directly to a 3-/2 inch or 4 inch octagonal, -/2 inch
deep electrical box, or
2. To a 4 inch square electrical box by using a plaster ring
with the supplied mounting bracket kit.
Spacing
Spacing of 30 ft. on a smooth ceiling as per CAN/ULC-
S536. Where conditions or response requirements vary,
other spacing may apply.
Wiring Installation Guidelines
All wiring must be installed in compliance with the Na-
tional Electrical Code and the applicable local codes, and
any special requirements of the local authority having
jurisdiction. Proper wire gauges should be used. The con-
ductors used to connect smoke detectors to control panels
and accessory devices should be color-coded to prevent
wiring mistakes. Improper connections can prevent a sys-
tem from responding properly in the event of a fire.
NOTE:
Refer to releasing device manufacturer’s instal-
lation instruction for proper connections.
NOTE:
Contacts are shown in stand-by mode and will
transfer in alarm condition.
CAUTION
For system supervision: for terminals , 2, 7, and 8, do not
use looped wire under terminals. Break wire run to provide
system supervision of connections.
For signal wiring (the wiring between interconnected de-
tectors), it is recommended that the wire be no smaller
than 8 gauge. Wire sizes up to 2 gauge wire may be
used. For best system performance, the power (+) and (–)
loop wires should be twisted pair and installed in separate
grounded conduit to protect the loop from extraneous elec-
trical interference.
Smoke detectors and alarm system control panels have
specifications for allowable loop resistance. Consult the
control panel manufacturer’s specifications for the total
loop resistance allowed for the particular model control
panel being used before wiring the detector loops.
Wire connections are made by stripping about 3/8
"
of insu-
lation from the end of the wire (use strip gauge molded in
base), sliding the bare end of the wire under the clamping
TAMPER
RESISTANT
TAB
TO MAKE DETECTOR TAMPER RESISTANT,
BREAK OFF TAB EXTENSION
AT SCRIBED LINE
Figure 1. Flush mounting of detector on 4 inch oc-
tagonal box:
Figure 2. Detector mounting bracket:
A78-554-02
A78-534-00
COMMON
N/O
N/C
AUXILIARY
CONTACTS
FORM C
4
5
6
7
8
2 1
+
-
POWER
ALARM
CONTACTS
FORM A
N/O
COMMON
N/O
N/C
(OPTIONAL)
RELEASING
DEVICE
4 5
6
7 8
2 1
+
-
COMMON
N/O
N/C
(OPTIONAL)
RELEASING
DEVICE
4 5
6
7 8
2 1
+
EOL
POWER
SUPERVISION
RELAY
MODULE
A77-716B
SUGGESTED
EOL
RESISTOR
CLASS A OPTIONAL WIRING
INITIATING
LOOP
POWER
TO
DETECTORS
ULC LISTED
COMPATIBLE
CONTROL
PANEL
+
-
+
-
-
A78-8-00
A78-554-0
Figure 3. Wiring diagram for models 1412A and 1424A detectors used with Class A
or Class B four-wire control panels.
