Siemens FDOT421 (S54320-F6-A1) is an intelligent, addressable multi-criteria fire detector that combines a photoelectric smoke sensor and a thermal sensor, with built-in ISOtechnology for True Class-X SLC performance.
The detector gathers smoke and thermal data and analyzes it in a neural network, comparing the signals with known fire signatures and with deceptive phenomena such as dust, steam and aerosols that cause other detectors to false alarm. Alarm Source 1 (neural network) runs a Standard profile, the default for clean areas such as offices and hotel lobbies, or a Duct profile for direct in-duct use. Alarm Source 2 (thermistor) gives heat-only detection, fixed at 135°F (57°C) by default or rate-of-rise at 15°F (8.3°C) per minute. Each detector is self-testing, with complete diagnostics every 10 seconds and sensitivity self-monitored within UL limits. It works with Desigo Fire Safety Modular, FireFinder XLS/V and FC/FV2025 and FC/FV2050 panels.
Specifications
| Part number |
S54320-F6-A1 |
| Sensing |
Photoelectric smoke and thermal (heat), multi-criteria |
| Input voltage range |
16 to 30 VDC |
| Standby current |
250 µA maximum |
| Alarm current |
410 µA maximum |
| Thermal rating |
Fixed 135°F (57°C) or rate-of-rise 15°F/min (8.3°C/min) |
| Operating temperature |
32°F to 100°F (0°C to 38°C) |
| Relative humidity |
0 to 95% non-condensing |
| Maximum spacing, smoke |
30 ft centers (900 sq ft) per NFPA 72 and ULC-S524 |
| Maximum spacing, heat |
50 ft centers (2,500 sq ft) per NFPA 72 and ULC-S530 |
| Isolation |
Built-in ISOtechnology; up to 252 isolation devices per SLC |
| LED |
Tri-color with 360° view: green normal, yellow trouble, red alarm |
| Weight |
0.317 lb (0.144 kg) |
| Certifications |
UL 268 7th Edition (open area), UL 268A (duct), UL 521, ULC-S529, ULC-S530, FM 3230, FM 3210; CSFM 7272-0067:0258 |
Installation notes
- Mounts on a DB-11, DB-11E or DB2-HR base, which fits a 4 in. octagonal, square or single-gang electrical box.
- The DB-11 base accepts the LK-11 locking kit to prevent unauthorized removal of the detector head.
- T-tapping is permitted only for Style 4 (Class B) wiring.
- In NFPA 72 Class X applications SLC polarity must be maintained; in mixed mode, a maximum of 30 non-isolated devices are allowed between isolation devices.
- Addresses are set electronically with the Siemens DPU field programmer/test unit.
- Each detector ships with a protective dust cover.
- The STI-9604 guard is certified for mechanical protection.
Related models
-
DB-11 / DB-11E — detector mounting bases
-
DB2-HR — relay base for Siemens standard and advanced detectors
-
ABHW-4B / ABHW-4S — audible bases, 3,000 Hz and 520 Hz low-frequency
-
DPU — device programmer and loop tester
Specifications taken from the Siemens data sheet 6150 "Multi-Criteria Fire Detector Model FDOT421." Manufacturer specifications are subject to change without notice.
Documents
FAQ
Is a base included with the FDOT421?
No. It mounts on a DB-11, DB-11E or DB2-HR base, ordered separately.
Which panels support the FDOT421?
Siemens Desigo Fire Safety Modular, FireFinder XLS/V and the FC/FV2025 and FC/FV2050 panels.
What heat detection settings does it have?
The thermal sensor can be set to fixed 135°F (57°C), the default, or rate-of-rise at 15°F (8.3°C) per minute.
What spacing applies?
30 ft centers for smoke detection and 50 ft centers for heat detection, per NFPA 72.
