24
Fig. 44 — Return Air Sampling Tube Location
(View reoriented to show opposite side for clarity.)
Completing Installation of Return Air Smoke
Detector
Use the following steps to complete the installation of the
return air smoke detector.
1. Unscrew the two screws holding the return air sensor
detector plate. See Fig. 45. Save the screws.
Fig. 45 — Return Air Smoke Detector Shipping Position
2. Remove the return air smoke sensor module and its
detector plate.
3. Rotate the detector plate so the sensor is facing outwards
and the sampling tube connection is on the bottom. See
Fig. 46.
4. Screw the sensor and detector plate into its operating position
using screws from Step 1. Ensure the sampling tube connec
-
tion is on the bottom and the exhaust tube is on the top.
5. Connect the flexible tube on the sampling inlet to the sam
-
pling tube on the basepan.
6. For units with an economizer, the sampling tube is inte
-
grated into the economizer housing but connecting the
flexible tubing to the sampling tube is the same.
Fig. 46 — Return Air Smoke Detector Operating Position
FIOP Smoke Detector Wiring and Response
ALL UNITS
The FIOP smoke detector is configured to automatically shut
down all unit operations when a smoke condition is detected.
See Fig. 47, Smoke Detector Wiring.
HIGHLIGHT A
Smoke detector NC contact set will open on smoke alarm con
-
dition, de-energizing the ORN conductor.
HIGHLIGHT B
24-v power signal using the ORN lead is removed at the smoke
detector input on UCB; all unit operations cease immediately.
RTU OPEN CONTROLS
Unit operating functions (fan, cooling and heating) are termi
-
nated as described above. In addition:
HIGHLIGHT C
On smoke alarm condition, the smoke detector NO Alarm con
-
tact will close, supplying 24-v power to GRA conductor.
HIGHLIGHT D
WHT lead at Smoke Alarm input on UCB provides 24-v signal
to FIOP DDC control.
RTU OPEN
The 24-v signal is conveyed to RTU Open-J1-10 input termi
-
nal. This signal initiates the FSD sequence by the RTU Open
control. FSD status is reported to connected BAS network.
USING REMOTE LOGIC
Six conductors are provided for field use (see Highlight E) for
additional annunciation functions.
ADDITIONAL APPLICATION DATA
Refer to the application data document “Factory Installed
Smoke Detectors for Small and Medium Rooftop Units 2 to 25
Tons” for discussions on additional control features of these
smoke detectors including multiple unit coordination.
RETURN AIR
SAMPLING TUBE
SAMPLE TUBE
SCREWS
FLEXIBLE EXHAUST TUBES
RETURN AIR SMOKE DETECTOR
(Operating Position Shown)
SCREWS (2)
SAMPLE TUBE
CONTROLLER
MODULE
