Duct Smoke Detector 2:1 Capability

InnovairFlex™ 2 Sensors to 1 Power Board Capability
Duct Smoke Detector 2:1 Capability
InnovairFlex 4-wire duct smoke detector has the ability to power two sensors
from one power board. With its 2:1 sensor-to-power board capability the
power board of the D4120 may be used to monitor a second D4S sensor
simultaneously. This is perfect for applications where monitoring both supply
and return are required.
For applications where space is at premium try the fully distributed option with
a separate power board (D4P120) and up to two sensors (D4S). Mount the
power board (D4P120) remotely in a convenient and accessible location and
mount the sensor components where needed to monitor air moving through
the HVAC system.
Code required remote monitoring can be accomplished with the RTS2 or
RTS2-AOS remote test accessory which has the capability of monitoring
two separate sensors tied back to one power board.
2:1 Sensor-to-Power Board Configuration
The D4120 duct smoke detector or D4P120 power board only is capable of
controlling a second housed sensor. The additional sensor, model D4S, can
be wired to the power board per the following:
1. C
onnect wires to the four wire terminals in the corner of the D4S sensor
housing designated as Tamper (Y,Y), +R, and –B. Route wires through the
conduit openings in the sensor housing and D4120 power board housing.
2. C
onnect the opposing ends of the wires to the terminal connections
marked “Sensor 2” on the Power board. Ensure that wires are
connected to the appropriate terminal locations. A No. 0 or 1 phillips
screwdriver should be used for terminal connection. The tamper
terminals are not polarity sensitive.
3. Adjust the middle dip switch on the power board to indicate (2) sensors.
4. The D4S can only be used with InnovairFlex models and is not
compatible with previously sold detectors.
5. Where RTS2 or RTS2-AOS is required, the wiring configuration is as follows:
(-) ACC
(+) ACC
ACC (+)
(-) AUX
ACC (-)
AUX (+)
AUX (-)
(+) AUX
NOTE: If polarity of Acc. (+) and Acc. (­—)
are reversed, an Amber LED on sensor 2
of the duct smoke detector power board
will exist indicating a trouble condition.
*It is recommended that 18 awg or greater
wire be used and limit wire runs to 25
ohms or less per interconnecting wire.
w w w. sys te m s e n s o r. c o m / fl ex
HVFL30201 • 7/13