The Siemens OP121 (part number 500-095992) is an addressable photoelectric smoke detector designed for Siemens fire alarm systems. Using light-scattering photoelectric technology, the OP121 provides reliable early-warning detection of slow-smoldering fires — the most common fire type in commercial occupancies — while communicating device status and alarm conditions over the Siemens addressable loop.
The OP121 is built for straightforward commercial applications where photoelectric-only detection is appropriate: office buildings, hotels, healthcare facilities, and light industrial environments. It mounts to the standard Siemens DB-11 base for easy installation and head replacement during routine maintenance or testing.
Key Features
- Photoelectric sensing for reliable smoke detection and reduced nuisance alarms
- Siemens addressable protocol — unique device addressing per loop
- Continuous diagnostic reporting to the fire alarm control panel
- Compatible with standard Siemens DB-11 detector base
- UL 268 listed
- Low-profile design for clean ceiling installations
Specifications
- Part Number: 500-095992
- Protocol: Siemens addressable
- Base: DB-11 (required, sold separately)
- Operating Temperature: 32°F–100°F (0°C–38°C)
For more information, contact the Life Safety Consultants team at (888) 557-0558, or email us at: sales@lifesafetycom.com
Additional information
| Weight | .2 lbs |
|---|---|
| Dimensions | 4 × 4 × 2 in |
| Condition | New |
| Part Type | Photoelectric, Smoke Detector |
| Manufacturers | Siemens |
| Compatible Panels | Conventional panels (2-wire and 4-wire IDC, panel-agnostic within voltage spec) |
| Compatible Bases | N/A – conventional detector, see panel documentation for base/mounting |
| Cross Reference | S54370-C5-A1, S54370 series |
| Detection | Photoelectric conventional, Circuit: 2-wire or 4-wire IDC, Part #: S54370-C5-A1, Not addressable |
