Models 2251B, 2251TB and 2251TMB are plug-in type smoke sensors that combine a photoelectronic sensing chamber with addressable-analog communications. The sensors transmit an analog representation of smoke density over a communication line to a control panel. Rotary-decade switches are provided for setting the sensor’s address. Two LEDs on the sensor are controlled by the panel to indicate sensor status. An output is provided for connection to an optional remote LED annunciator (P/N RA400Z/RA100Z). Models 2251TMB and 2251TB combine a photoelectronic sensing chamber and 135°F (57.2°C) fixed temperature heat detector. The 2251B, 2251TB and 2251TMB require compatible addressable communications to function properly. Connect these sensors to listed-compatible control panels only.
Operating Voltage Range: 15 to 32 VDC
Standby Current: 300μA @ 24 VDC (one communication every 5 seconds with LED blink enabled)
Maximum Alarm Current (LED on:) 6.5 mA @ 24 VDC
Operating Humidity Range: 10% to 93% Relative Humidity, Non-condensing
Operating Temperature Range: 32°F to 120°F (0°C to 49°C) 2251B; 32°F to 100°F (0°C to 38°C) 2251TB and 2251TMB
Heat Sensor: 135°F Fixed Temperature Electronic Thermistor
Height: 2.0 ̋ (51 mm) installed in B210LP Base
Diameter: 6.1 ̋ (155 mm) installed in B210LP Base; 4.1 ̋ (104 mm) installed in B501 Base
Weight: 5.2 oz. (147 g)
Returns and Exchanges
There are a few important things to keep in mind when returning a product you purchased.You can return unwanted items by post within 7 working days of receipt of your goods.
- You have 14 calendar days to return an item from the date you received it.
- Only items that have been purchased directly from Us.
- Please ensure that the item you are returning is repackaged with all elements.
Ship your item back to Us
Firstly Print and return this Returns Form to:
30 South Park Avenue, San Francisco, CA 94108, USA
Please remember to ensure that the item you are returning is repackaged with all elements.
For more information, view our full Returns and Exchanges information.