Siemens FDOOT441 — an addressable multi-criteria fire detector combining optical and thermal sensing in one head.
The criteria are optical and thermal, not gas. The chamber holds two optical transmitters, one receiver and two thermal sensors: one transmitter lights the smoke from the front and the other from behind, so forward and backward scatter together separate light particles from dark.
- UL 268 7th Edition, UL 268A for direct in-duct use, UL 521 as a heat detector
- UL certified sensitivity 0.88 to 3.35 %/ft; NFPA 76 VEWFD profile at 0.2 and 1.0 %/ft
- 13 to 32 VDC; 650 µA maximum alarm, 360 µA maximum standby
- Five fixed heat thresholds from 135 to 175 °F, four combinable with rate of rise
- Air velocity 0 to 4,000 ft/min open area and in duct; 32 to 120 °F
- 22 application profiles; dual isolators for Class X operation
- Addresses 001 to 252, set with the DPU programmer
The head ships with a dust cover but no base: it needs a DB-11 or DB-11E surface base on a 4 in. octagonal, square or single gang box, or DB2-HR with relay. FDOOTC441 is the near-identical part that adds a carbon monoxide sensor.
Documents
FAQ
Is a base included?
No. The FDOOT441 uses a DB-11 or DB-11E surface base on a 4 in octagonal, square or single-gang box, or the DB2-HR base with relay. A protective dust cover is included.
Which panels is it compatible with?
Siemens lists the Desigo Fire Safety FC2005, FC2025, FC2050, FV2025 and FV2050, Desigo Modular, and the FireFinder XLS and XLSV.
Can it be used directly in a duct?
Yes. It is UL 268A certified for direct in-duct use at air velocities up to 4,000 ft/min.
How is the address set?
Addresses are set electronically with the Siemens DPU / 8720 field programmer and test unit, not with dials or rotary switches.
