Use and Care Manual
15
• When alarms are hardwire interconnected, all interconnected units must be powered from a single circuit.
• A maximum of 24 Kidde Safety devices may be interconnected in a multiple station arrangement. The intercon-
nect system should not exceed the NFPA interconnect limit of 12 smoke alarms and/or 18 alarms total (smoke, CO,
Smoke/ CO Combination, heat, etc.). With 18 alarms interconnected, it is still possible to interconnect up to a total of
6 remote signaling devices and / or relay modules.
• The maximum wire run distance between the first and last unit in an interconnected system is 1000 feet.
• Figure 9-A illustrates interconnection wiring. Improper connection will result in damage to the alarm, failure to
operate, or a shock hazard.
• Make certain alarms are wired to a continuous (non-switched) power line.
NOTE: Use standard UL Listed household wire (as required by local codes) available at all electrical supply
stores and most hardware stores.
• For best results to minimize nuisance alarms, interconnected alarms should be on a dedicated line. If not on a dedi-
cated line, it is suggested that the smoke alarms share a lighting load circuit that does not have a dimmer associated
with it. If receptacles must be placed on the same line it is suggested that they be placed ahead of the smoke alarms
(see Figure 9-C). This will prevent large voltage drops from occurring between the first and last alarm in the circuit.
Figure 9-A, Interconnect Wiring Diagram
Existing Kidde
AC Connector
(either connector
can be used for
this model)
AC connector
shipped with
product
Wires on alarm harness: Connected to:
Black: Hot side of AC line
White: Neutral side of AC line
Red: Interconnect lines (red wires) of other
units in the multiple station set-up
Figure 9-C
Figure 9-B
Service
Panel
Receptacles Interconnected alarms
Wiring practice that has had good results
in preventing nuisance alarms
Additional
Alarm
WHITEWHITE BLACK
RED
Additional
Alarm
WHITE
BLACK
RED
FUSE OR CIRCUIT BREAKER
RED
BLACK
Kidde Relay Module
SM120X, CO120X
or both
Optional
Accessory
First
Alarm