System Sensor DNR — InnovairFlex intelligent (addressable) non-relay photoelectric duct smoke detector housing, UL 268A listed for air handling systems, with an adjustable body that fits both square and rectangular mounting footprints and mounts to round or rectangular duct.
The DNR monitors air moving through HVAC ductwork so the fire alarm system can shut down fans and dampers before smoke is distributed through a building. It is an addressable device powered from the communication line only, with no on-board relay — the housing has space to mount a relay module if the application needs dry contacts. The detector head and the sampling tube are ordered separately: choose a sampling tube from the DST range to match duct width, and pair the housing with a compatible plug-in sensor head whose code wheels set the address. Patented tool-free plug-in sampling tubes install from the front or the back of the housing, a ¾″ conduit knockout and enlarged wiring space simplify termination, and a clear cover allows visual inspection without opening the unit. A cover tamper feature reports a trouble signal if the sensor cover is removed or improperly fitted. The InnovairFlex line is compatible with previous Innovair models, including remote test accessories, which makes retrofits straightforward.
Specifications
| Model |
DNR (InnovairFlex intelligent non-relay duct smoke detector) |
| Type |
Intelligent/addressable, photoelectric, integrated low-flow technology; non-relay |
| Detector head |
Sold separately |
| Power |
Communication line power only |
| Electrical ratings |
Per the detector head installation manual — the housing data sheet publishes no separate voltage or current figures |
| Air duct velocity |
100 to 4,000 ft/min (0.5 to 20.32 m/s) |
| Operating temperature |
−4°F to 158°F (−20°C to 70°C) |
| Storage temperature |
−22°F to 158°F (−30°C to 70°C) |
| Operating humidity |
0% to 95% RH, non-condensing |
| Size, rectangular configuration |
14.38″ (37 cm) length × 5″ (12.7 cm) width × 2.5″ depth |
| Size, square configuration |
7.75″ (19.7 cm) length × 9″ (22.9 cm) width × 2.5″ depth |
| Weight |
1.6 lb (0.73 kg) |
| Terminals |
Strip and clamp, 12–18 AWG |
| Conduit knockout |
¾″ |
| Environmental rating |
None on DNR — NEMA 4 applies to the DNRW only |
| Testing |
Local test by magnetic switch; remote test via RTS151 or RTS151KEY remote test station |
| DCOIL current (if fitted) |
17.5–26.4 VDC, 95 mA max |
| RA100Z accessory current at 24 VDC |
0 mA standby, 12 mA max alarm |
| RTS151 / RTS151KEY current at 24 VDC |
0 mA standby, 12 mA max alarm |
| Listing |
UL 268A, for use in air handling systems |
Installation notes
-
Head and sampling tube are not included: the DNR is the housing. Order a compatible plug-in sensor head and a DST sampling tube sized to the duct — DST1 up to 1 ft, DST1.5 for 1–2 ft, DST3 for 2–4 ft, DST5 for 4–8 ft, DST10 for 8–12 ft. An ETX metal exhaust tube and P48-21-00 end cap complete the assembly.
-
Non-relay means no dry contacts: the DNR signals through the addressable loop only. If the job requires contacts for fan shutdown or damper control, mount a relay module in the space the housing provides, or specify a relay version.
-
Remote test needs both a coil and its own supply: using an RTS151 or RTS151KEY requires the separately sold DCOIL accessory, and the test coil circuit requires an external UL listed 24 VDC power supply — it is not powered from the communication line. Alternatively, an “R” remote-test-capable detector head works with the RTS151/RTS151KEY without the DCOIL.
-
Air velocity limits are hard limits: smoke entry depends on differential pressure across the sampling tube. Below 100 ft/min or above 4,000 ft/min the detector is outside its listing; verify design airflow at the mounting location, not just at the fan.
-
Cover tamper is a trouble, not an alarm: a removed or improperly seated sensor cover initiates a trouble signal. Expect it at the panel during head replacement and reseat the cover fully.
-
Indoor housing: the DNR carries no enclosure rating. For rooftop or wet locations use the DNRW, whose NEMA 4 watertight UV-resistant housing removes the need for a separate enclosure, or fit the DH400OE-1 weatherproof enclosure.
-
Sampling tube orientation: the InnovairFlex tube can be inserted from the front or the back of the detector and locks in place; it is released with the front or rear locking tab. Tube inlet holes must face into the airflow.
Related models and accessories
-
DNRW — same intelligent non-relay duct detector in a watertight NEMA 4, UV-resistant housing for outdoor and wash-down locations
-
DCOIL — remote test coil, required with RTS451/RTS451KEY/RTS151/RTS151KEY
-
RTS151 / RTS151KEY — remote test station, plain and key-locked
-
RA100Z — remote annunciator alarm LED, one per unit
-
M02-04-00 — test magnet for local magnetic-switch testing
-
DH400OE-1 — weatherproof enclosure
Specifications taken from the System Sensor data sheet “Intelligent Non-Relay Photoelectric Duct Smoke Detector,” document A05-0422-005 (9/10). Manufacturer specifications are subject to change without notice.
