Data Sheet for Product

Siemens
Smart Infrastructure - Building Products
–2–
usa.siemens.com/fire
Sensitivity Settings
Application Parameter Sets
Model FDO421 provides four (2) pre-programmed sensitivity parameter sets that can be selected by the Siemens fire-alarm
control panel in order to match the expected application or environmental conditions:
• Standard
• Air-duct
Standard:
This application parameter set, which is ideal for normal office | hotel-lobby-type
applications, is the default setting.
Air-Duct:
This application parameter set is used when the detector is used a UL268A (DI)
compliant, direct in-air duct application without a duct housing.
Model FDO421 does not require a field sensitivity test. Model FDO421 is UL Listed as a self-testing
device and complies with NFPA 72 as a self-monitoring detector and control-panel arrangement. This
parameter set is also used when Model FDO421 is used in air-duct housings (Models FDBZ492 and
FDBZ492-HR).
A quick visual inspection is sufficient to indicate the condition of Model FDO421 at any time. If more
detailed information is required, a printed report can be provided from the compatible FACP, indicating
the status and settings assigned to each individual detector. When Model FDO421 moves to `Alarm’
mode, the detector will flash R
ED and continue flashing until the system is reset at the FACP. At that
same time, any user-defined, system-alarm functions programmed into the system are activated.
Model FDO421 contains a tri-color LED indicator, capable of flashing any one (1) of three (3) distinct
colors: G
REEN | YELLOW | RED. During each flash interval, the microprocessor-based detector monitors
the following scenarios:
• Smoke sensitivity is within the range indicated on the nameplate label
• Smoke in its sensing chamber
• Internal sensors and electronics are functional
Based on the results of the monitoring, the LED indicator flashes the following:
FLASH COLOR CONDITION
FLASH INTERVAL
[in seconds]
GREEN

:
Normal supervisory operation.
Smoke sensitivity is within rated limits.
10
YELLOW: Detector is in trouble and needs replacement. 4
RED: `Alarm’ condition 1
NO FLASH: Detector is not powered.
–
 denotes LED can be turned OFF
Please follow the corresponding description of the panel used.
1. Labyrinth
2.
Optical
transmitter
3.
Optical
receiver
1. Dust cover
2.
Photoelectric
smoke
detector
1
2
Model FDO421-