Data Sheet for Product
Siemens 
Smart Infrastructure - Building Products 
 –4– 
usa.siemens.com/fire 
Model or 
Type 
Part 
Number 
Description 
FDBZ492 
S54319-B22-A1 
A two-wire addressable or conventional duct detector (without relays) designed for direct 
use on heating, ventilating and air-conditioning (HVAC) air-duct systems. When 
equipped, the air-duct detector housing will signal the presence of smoke being carried 
through the duct system. 
For use with the following Models: 
▪  OP121 
▪  FP-11 
▪  HFP-11 
▪  HFPO-11 
▪  PE-11 
▪  FDO421 
▪  FDOOT441 
▪  FDOOTC441 
▪  PE-11C 
▪  SFP-11 
▪  SFPO-11 
FDBZ492-HR 
S54319-B23-A1 
A two-wire addressable duct detector (with relays) designed for direct use to HVAC air-
duct systems and works with the Remote Test Switch (FDBZ492-RTL). This part has a 
programmable relay base, and when equipped, the addressable air-duct detector housing 
will signal the presence of smoke being carried through the duct system. 
For use with the following Models: 
▪  FDO421 
▪  FDOOT441 
▪  FDOOTC441 
▪  FP-11 
▪  HFP-11 
▪  HFPO-11 
▪  SFPO-11 
▪  SFP-11 
FDBZ492-R 
S54319-B24-A1 
A two-wire conventional duct detector with relays designed for direct use on HVAC air-
duct systems. This detector has a relay base, and when equipped with conventional air-
duct housing, will signal the presence of smoke being carried through the duct system. 
For use with the following Models: 
▪  PE-11  PE-11C 
▪  OP121  
FDBZ492-PR 
S54319-B25-A1 
A four-wire conventional duct detector with relays and a built-in power supply. Housing is 
designed for direct use to HVAC air-duct systems. It has a relay base with a built-in power 
source.  When equipped with conventional air-duct housing, this duct detector will signal 
the presence of smoke being carried through the duct system. 
For use with the following Models: 
▪  PE-11  PE-11C 
▪  OP121 
FDBZ492-RTL 
S54319-S27-A1 
Device is used for manual testing via a key-switch for duct-housing Models FDBZ492-R, 
FDBZ492-PR and FDBZ492-HR. Device mounts remotely from the conventional and 
addressable air-duct housing, allowing for manual relay-output control.  The duct-detector 
remote key-switch also indicates the current state of the detector. 
For use with the following Models: 
▪  FDBZ492-HR  
▪  FDBZ492-R 
▪  FDBZ492-PR 
FDBZ-WT 
S54319-B26-A1 
An optional, separate watertight NEMA 4X enclosure (Model FDBZ-WT) that provides 
added watertight protection for any of the Model FDBZ492-series duct housings. The duct 
housing fits into the separate 4X enclosure.  This part allows the air-duct detector housing 
to be installed in the separate enclosure, and can be used in either an outdoor area or in 
environments where excessive moisture is prevalent. 
For use with the following Models: 
▪  FDBZ492 
▪  FDBZ492-R 
▪  FDBZ492-HR 
▪  FDBZ492-PR 
ST-10 
500-649710 
Sampling tube for Ducts 6” to 1’ 
ST-25 
500-649711 
Sampling tube for Ducts over 1’ to 3’ 
ST-50 
500-649712 
Sampling tube for Ducts 3” to 5’ 
ST-100 
500-649713 
Sampling tube for Ducts 5’ to 10’ 
Details for Ordering 
Note: Model names in Red for use in Canada. 
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