Siemens FDO421 (S54320-F4-A1) Smoke Detector

Siemens FDO421 (S54320-F4-A1) Photoelectric Smoke Detector

Model FDO421 incorporates an optical sensor using a light-scattering detection principle.

The device utilizes advanced software algorithms to analyze the signals and provides highly stable and accurate smoke detection.

Model FDO421 also uses state-of-the-art microprocessor circuitry with error checks, detector self-diagnostics, and supervision programs. Each detector is UL 268 7th edition listed, incorporating advanced built-in ISOtechnologyTM - True Class-X SLC operation (use is optional), greatly improving system reliability and circuit integrity while providing advanced addressable fault finding.

The unit fits into one (1) wall-or-ceiling footprint and only occupies one (1) address on the signal-line circuit (SLC). Model FDO421 is a plug-in, two-wire, addressable photoelectric smoke detector whose value is increased with a built-in ISOtechnology feature. Model FDO421 is Underwriters’ Laboratories Listed [UL268A Listed for direct in-air duct usage].

Each detector comprises a dust-resistant photoelectric chamber and microprocessor-based electronics with a low-profile plastic housing. Every Model FDO421 fire detector is shipped with a protective dust cover.