28
Controller
The controller (see Fig. 34) includes a controller housing,
a printed circuit board, and a clear plastic cover. The
controller can be connected to one or two compatible duct
smoke sensors. The clear plastic cover is secured to the
housing with a single captive screw for easy access to the
wiring terminals. The controller has three LEDs: Power,
Trouble and Alarm. A manual test/reset button is located
on the cover face.
Controller Housing
and Electronics
Conduit Couplings
(supplied by installer)
Fastener
(2X)
Alarm
Trouble
Power
Test/Reset
Switch
Controller Cover
Cover Gasket
(ordering option)
Terminal Block Cover
Conduit Support Plate
Conduit Nuts
(supplied by installer)
Duct Smoke Sensor
Controller
C08208
Fig. 34
−
Controller Assembly
Sensor
The sensor (see Fig. 35) includes a plastic housing, a
printed circuit board, a clear plastic cover, a sampling
tube inlet and an exhaust tube. The sampling tube, when
used, and exhaust tube are attached during installation.
The sampling tube varies in length depending on the size
of the rooftop unit. The clear plastic cover permits visual
inspections without having to disassemble the sensor. The
cover attaches to the sensor housing using four captive
screws and forms an airtight chamber around the sensing
electronics. Each sensor includes a harness with an RJ45
terminal for connecting to the controller. Each sensor has
four LEDs: Power, Trouble, Alarm and Dirty. A manual
test/reset button is located on the left side of the housing.
Air is introduced to the duct smoke detector sensor’s
sensing chamber through a sampling tube that extends into
the HVAC duct and is directed back into the ventilation
system through a (shorter) exhaust tube. The difference in
air pressure between the two tubes pulls the sampled air
through the sensing chamber. When a sufficient amount of
smoke is detected in the sensing chamber, the sensor
signals an alarm state and the controller automatically
takes the appropriate action to shut down fans and
blowers, change over air handling systems, notify the fire
alarm control panel, etc.
The sensor uses a photoelectric (light scattering principle)
process called
differential sensing
to prevent gradual
environmental changes from triggering false alarms. A
rapid change in environmental conditions, such as smoke
from a fire, causes the sensor to signal an alarm state but
dust and debris accumulated over time does not.
See Detail A
Detail A
Plug
Sampling Tube
(ordered separately)
Coupling
Magnetic
Test/Reset
Switch
Alarm
Trouble
Power
Dirty
Sensor Cover
Cover Gasket
(ordering option)
Sensor Housing
and Electronics
Exhaust Gasket
Exhaust Tube
Duct Smoke Sensor
Intake
Gasket
TSD-CO2
(ordering option)
C08209
Fig. 35
−
Smoke Detector Sensor
For installations using two sensors, the duct smoke
detector does not differentiate which sensor signals an
alarm or trouble condition.
Smoke Detector Locations
Supply Air
The Supply Air smoke detector sensor is located to the
left of the unit’s indoor (supply) fan. See Fig. 36. Access
is through the fan access panel. There is no sampling tube
used at this location. The sampling tube inlet extends
through the side plate of the fan housing (into a high
pressure area). The controller is located on a bracket to
the right of the return filter, accessed through the lift
−
off
filter panel.
Summary of Contents for 581J-17-28
Page 73: ...73 APPENDIX IV WIRING DIAGRAMS cont C160042 Fig 72 581J D17 D28 Power Diagram 208 230 3 60 ...
Page 74: ...74 APPENDIX IV WIRING DIAGRAMS cont C160043 Fig 73 581J D17 D28 Power Diagram 460 3 60 ...
Page 75: ...75 APPENDIX IV WIRING DIAGRAMS cont C160044 Fig 74 581J D17 D28 Power Diagram 575 3 60 ...
Page 80: ...80 APPENDIX IV WIRING DIAGRAMS cont C160049 Fig 79 RTU OPEN Wiring Diagram ...
