Product Details
The Siemens FDO421 is an intelligent, addressable photoelectric smoke detector designed for use with Desigo Fire Safety and FireFinder XLS/V series control panels. It incorporates microprocessor-based signal processing and an optical light-scattering sensing chamber to provide stable and accurate smoke detection.
The FDO421 features built-in ISOtechnology to support True Class-X SLC operation (optional use), enhancing loop reliability and enabling advanced addressable fault isolation (up to 252 isolation devices per SLC). The detector is polarity insensitive via SureWire technology and occupies one address on the signaling line circuit.
The unit includes automatic environmental compensation, extended temperature and humidity operating range, self-diagnostics performed every 10 seconds, and a tri-color 360° LED for status indication. The detector is UL 268 7th Edition listed and approved for direct in-air duct applications (UL 268A) where applicable.