System Sensor 4WTAR-B — conventional 4-wire i3 series photoelectric smoke detector combining a 135°F fixed thermal sensor, an 85 dBA sounder and a Form C relay in one plug-in head, supplied with its mounting base.
The 4WTAR-B is the sounder-plus-relay member of the i3 sounder/relay family. Smoke or heat puts the head into alarm, the integral sounder produces an 85 dBA temporal tone for local notification, and the Form C relay is available for auxiliary functions such as door holders, fan shutdown or ancillary signaling. Because it is a 4-wire detector, it takes operating power from a separate supervised power circuit and reports alarm through its initiating contacts, so its own alarm draw of 50 mA must be carried by that power supply. Drift compensation and smoothing algorithms reduce nuisance alarms from dust accumulation and RF interference, and dual-color LEDs indicate power up, standby, out-of-sensitivity, freeze trouble and alarm. Base included.
Specifications
| Model |
4WTAR-B (i3 series, sounder and relay) |
| Detection |
Photoelectric smoke with thermal sensor |
| Wiring |
4-wire |
| Operating voltage |
12/24 V nominal, non-polarized; 4-wire range 10 V to 35 V |
| Maximum ripple voltage |
30% of applied voltage (peak to peak) |
| Standby current |
50 µA maximum average |
| Maximum alarm current |
50 mA |
| Alarm contact ratings |
0.5 A @ 30 V AC/DC |
| Form C relay contact ratings |
2 A @ 30 V AC/DC |
| Sound pressure output |
85 dBA temporal tone |
| Sensitivity |
2.5%/ft. nominal |
| Thermal sensor |
135°F (57.2°C) fixed |
| Freeze trouble |
41°F (5°C) |
| Operating temperature |
32°F to 100°F (0°C to 37.8°C) |
| Operating humidity |
0 to 95% RH, non-condensing |
| Input terminals |
14–22 AWG, SEMS screws |
| Dimensions (including base) |
5.3″ (134 mm) diameter × 2.0″ (51 mm) height |
| Weight |
7.1 oz (200 g) |
| Listing |
UL 268, Fire Protection Signaling Systems |
| LED — power up |
Green and red both blink every 10 seconds, 80 second initial indication |
| LED — normal standby |
Green blinks every 5 seconds |
| LED — out of sensitivity |
Red blinks every 5 seconds |
| LED — freeze trouble |
Red blinks every 10 seconds |
| LED — alarm |
Red solid |
| Mounting |
3½″ octagonal, 4″ octagonal, single-gang or 4″ square back box with plaster ring, or direct to ceiling |
Installation notes
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50 mA alarm draw, not 35 mA: the 4WTAR-B and 4WITAR-B draw 50 mA in alarm, while the 4WTA-B and 4WTR-B draw 35 mA. Use 50 mA per head when sizing the 4-wire power supply and its standby battery.
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Two different contact ratings: the alarm initiating contacts are rated 0.5 A @ 30 V AC/DC, but the auxiliary Form C relay is rated 2 A @ 30 V AC/DC. Do not apply the Form C rating to the alarm contacts.
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4-wire minimum voltage is 10 V: 4-wire i3 detectors operate from 10 V to 35 V. The 8.5 V lower limit published for the family applies to the 2-wire models only.
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Remote maintenance signaling is a 2-wire feature: the 2W-MOD2 loop test/maintenance module generates remote maintenance signals for 2-wire i3 detectors. It does not provide that function for the 4-wire 4WTAR-B. Sensitivity on this head is checked with the SENS-RDR reader instead.
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Sounder synchronization: with an RRS-MOD reversing relay/synchronization module on the loop, all i3 sounders activate when one detector alarms and their output is synchronized, and sounders can be silenced from the panel.
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Temperature ceiling is 100°F: the thermal sensor limits the operating range to 32°F–100°F, lower than the 120°F ceiling of the photoelectric-only 4W-B. Keep it out of attics, unconditioned mechanical spaces and other locations that exceed 100°F.
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The thermal sensor is not isolated on this model: if the design requires a local alarm on smoke and a separate general alarm on heat, that is the 4WITAR-B isolated-thermal model, not the 4WTAR-B.
Related models
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4WTA-B — 4-wire photoelectric/thermal with 85 dBA sounder; 35 mA alarm current
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4WTR-B — 4-wire photoelectric/thermal without a sounder; 35 mA alarm current
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4WITAR-B — isolated thermal sensor with sounder and relay, for separate local and general alarm signaling; 50 mA
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2WTA-B — 2-wire photoelectric/thermal with sounder; alarm current limited by the control panel
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2WTR-B — 2-wire photoelectric/thermal with a Form C relay
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4WT-B — 4-wire photoelectric/thermal with no sounder and no relay
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RRS-MOD — reversing relay/synchronization module; SENS-RDR sensitivity reader; RT removal tool; A77-AB2 retrofit adapter bracket
Specifications taken from the System Sensor data sheet “Smoke Detectors with Sounder and Relay Option,” document A05-0348-004 (6/09). Manufacturer specifications are subject to change without notice.
