Data Sheet for Product

Siemens
Smart Infrastructure - Building Products
–3–
usa.siemens.com/fire
A quick visual inspection is sufficient to indicate the condition of the detector at any time. If more detailed
information is required, a printed report can be provided from the respective Desigo Fire Safety Modular |
FireFinder XLS/V | FC/FV20–series FACP that indicates the status and settings assigned to each individual detector.
Installation
All Model FDO421 intelligent, addressable detectors use a surface-mounting base (Model DB-11 or DB-11E), which
mounts on a 4-inch (10.2 cm.) octagonal, square or single-gang electrical back box. The base utilizes screw-clamp
contacts for electrical connections and self-wiping contacts for increased reliability.
The Model DB-11 detector base can be used with the optional Siemens Model LK-11 detector locking kit, which
contains 50 detector locks and an installation tool to prevent unauthorized removal of the detector head. Model DB-
11 has aesthetically conducive plugs to cover the outer mounting-screw holes.
Model FDO421 may be installed on the same initiating circuit with the Siemens Model `H’-series detectors
[when used with Desigo Fire Safety Modular | FireFinder XLS/V | FC/FV20–series FACPs] –
• XTRI series interface modules
• HFP-11, HFPT-11 detection devices
• HTRI series interface modules
• HCP output-control module
• HMS & XMS series manual stations
• HZM conventional zone module
Each detector, which is shipped with a protective dust cover, consists of the following:
• Built-in ISOtechnology for True-Class-X SLC performance
• Dust-resistant photoelectric chamber
• Microprocessor-based electronics with a low-profile plastic housing
All Model FDO421 intelligent, addressable detectors are approved for operation with the Underwriters’ Laboratories-
specified
temperature range of 32° to 120° (0° to 49°C). (See: installation manual P/N ─ A6V10323928 for further details)
Application Data
Installation of Model FDO421 smoke detectors require a two-wire circuit. In many retrofit cases, existing wiring may be
used. `T-tapping’ is permitted only for Style 4 (Class B) wiring. Model FDO421 is polarity insensitive, which can greatly
reduce installation and debugging times. When operating in NFPA 72 Class-X applications SLC polarity must be
maintained to support up to 252 isolation ready devices per loop. When used in mixed mode a maximum of 30 non-
isolated devices between isolation devices (wired in polarity-insensitive mode). See control panel install document for
further details.
Model FDO421 detectors can be applied within the maximum 30-feet center spacing (900 sq. ft. areas,) as referenced in
NFPA 72.This application guideline is based on ideal conditions − specifically, smooth ceiling surfaces, minimal air
movement, and no physical obstructions between potential fire sources and the actual detector. Do not mount detectors
near ventilation or heating and air conditioning outlets. Exposed joists or beamed ceilings may also affect safe
spacing limitations for detectors.
Should questions arise regarding detector placement, observe NFPA 72 guidelines. Good fire-protection-system
engineering and common sense dictate how and when fire detectors are installed and used. Contact your local
Siemens − Fire Safety distributor or sales office whenever you need assistance applying Model FDO421 in unusual
applications. Be sure to follow NFPA guidelines and UL Listed / ULC Listed installation instructions − included with every
Siemens − Fire Safety detector − and local codes as for all fire protection equipment.
Field-Device Programmer / Test Unit
Model FDO421 is compatible with the Siemens field-device programmer / test unit (Model DPU), which is a compact,
portable menu-driven accessory for electronically programming and testing these addressable detectors promptly and
reliably. For instance, the field technician selects the accessory’s program mode, and enters the desired address.
Model DPU eliminates the need for cumbersome, unreliable mechanical programming methods (e.g. – dials and rotary
switches), and reduces installation and service costs by electronically programming and testing the detector prior to
installation. When set in `test’ mode, Model DPU will perform a series of diagnostic tests without altering the address
or other stored data, allowing technicians to determine if the detector is operating properly.
Each field-device programmer / test unit operates on AC power or rechargeable batteries, providing flexibility and
convenience in the programming / testing of fire-safety equipment from practically any location. Additionally, with the
use of a Model DPU unit, there is no longer a cause for concern with any vibration, corrosion and other deteriorating
conditions that can accompany the vitality of electro-mechanical-addressing mechanisms.
Each detector fits into one (1) wall-or-ceiling footprint, and only occupies one (1) address on the signal-line circuit (SLC).
Dimensional Data