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Bosch D281A Dual-Chamber Ionization Smoke Detector
- Regular price
- $297.00
- Sale price
- $297.00
- Regular price
-
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Product Description P/N: D281A
Description
The Bosch D281A is an ionization smoke detector designed to identify smoke particles in commercial fire alarm applications. Its dual-chamber sensing design compares ionization current levels to determine alarm conditions while tolerating humidity, temperature variation, vibration, and electromagnetic interference. It is suitable for locations including plenum areas and raised compartments beneath floors.
Technical Specifications
| Condition | New/Never Used Surplus |
| Brand | Bosch |
| Category | Fire Alarm Systems |
| Part Number | D281A |
| Subcategory | Ionization Smoke Detectors |
| Product Type | Ionization Smoke Detector |
| Detection Technology | Dual-Chamber Ionization |
| Nominal Voltage | 24 VDC |
| Working Voltage (Two-Wire) | 15 to 33 VDC |
| Rated Voltage (Four-Wire) | 17.7 to 30 VDC |
| Standby Current | 0.04 mA |
| Surge Current | 0.2 mA |
| Maximum Alarm Current | 0.15 A at 24 VDC |
| Operating Temperature | +32°F to +120°F (0°C to +49°C) |
| Relative Humidity | 95% maximum |
| Detector Head Diameter | 4 in. (10.2 cm) |
| Detector Height | 1.5 in. (3.8 cm) |
| Color | White |
| Compatible Bases | D250A, D280A, D290, D291M, D291S |
| Weight | 3 lb |
Information About D281A
The D281A is a Bosch ionization smoke detector built around a removable, non-polarized 24 VDC detector head and dual-chamber sensing architecture. It is compatible with selected low-profile, tamper-resistant two-wire and four-wire detector bases, including Bosch D250A, D280A, and D290 models. The sensing assembly uses a sealed inner chamber as a controlled reference while the screened outer chamber responds to changes in airborne smoke particles. Integrated green and red LED indicators provide visual identification of powered and alarm states, while a moisture-resistant reed switch enables magnetic functional testing.
Key Features:
- Dual-Chamber Detection: Uses inner reference and outer sensing chambers to monitor changes caused by smoke particles.
- 24 VDC Detector Head: Features a removable, non-polarized head for straightforward installation and servicing.
- Flexible Base Compatibility: Supports selected Bosch two-wire, four-wire, and addressable detector bases.
- Wide Working Voltage: Operates from 15 to 33 VDC when configured for compatible two-wire applications.
- Status Indicators: Flashing green LED indicates applied power, while steady red identifies an alarm condition.
- Magnetic Testing: Moisture-resistant reed switch permits detector testing with an applied magnet.
- Environmental Tolerance: Designed to function under conditions involving humidity, vibration, temperature variation, and electromagnetic interference.
- Screened Sensing Chamber: Outer chamber screening helps filter dust and deter insects while permitting smoke entry.
The D281A delivers the reliability and precision required for smoke detection within compatible commercial fire alarm systems.
Description
The Bosch D281A is an ionization smoke detector designed to identify smoke particles in commercial fire alarm applications. Its dual-chamber sensing design compares ionization current levels to determine alarm conditions while tolerating humidity, temperature variation, vibration, and electromagnetic interference. It is suitable for locations including plenum areas and raised compartments beneath floors.
Technical Specifications
| Condition | New/Never Used Surplus |
| Brand | Bosch |
| Category | Fire Alarm Systems |
| Part Number | D281A |
| Subcategory | Ionization Smoke Detectors |
| Product Type | Ionization Smoke Detector |
| Detection Technology | Dual-Chamber Ionization |
| Nominal Voltage | 24 VDC |
| Working Voltage (Two-Wire) | 15 to 33 VDC |
| Rated Voltage (Four-Wire) | 17.7 to 30 VDC |
| Standby Current | 0.04 mA |
| Surge Current | 0.2 mA |
| Maximum Alarm Current | 0.15 A at 24 VDC |
| Operating Temperature | +32°F to +120°F (0°C to +49°C) |
| Relative Humidity | 95% maximum |
| Detector Head Diameter | 4 in. (10.2 cm) |
| Detector Height | 1.5 in. (3.8 cm) |
| Color | White |
| Compatible Bases | D250A, D280A, D290, D291M, D291S |
| Weight | 3 lb |
Information About D281A
The D281A is a Bosch ionization smoke detector built around a removable, non-polarized 24 VDC detector head and dual-chamber sensing architecture. It is compatible with selected low-profile, tamper-resistant two-wire and four-wire detector bases, including Bosch D250A, D280A, and D290 models. The sensing assembly uses a sealed inner chamber as a controlled reference while the screened outer chamber responds to changes in airborne smoke particles. Integrated green and red LED indicators provide visual identification of powered and alarm states, while a moisture-resistant reed switch enables magnetic functional testing.
Key Features:
- Dual-Chamber Detection: Uses inner reference and outer sensing chambers to monitor changes caused by smoke particles.
- 24 VDC Detector Head: Features a removable, non-polarized head for straightforward installation and servicing.
- Flexible Base Compatibility: Supports selected Bosch two-wire, four-wire, and addressable detector bases.
- Wide Working Voltage: Operates from 15 to 33 VDC when configured for compatible two-wire applications.
- Status Indicators: Flashing green LED indicates applied power, while steady red identifies an alarm condition.
- Magnetic Testing: Moisture-resistant reed switch permits detector testing with an applied magnet.
- Environmental Tolerance: Designed to function under conditions involving humidity, vibration, temperature variation, and electromagnetic interference.
- Screened Sensing Chamber: Outer chamber screening helps filter dust and deter insects while permitting smoke entry.
The D281A delivers the reliability and precision required for smoke detection within compatible commercial fire alarm systems.