The Fire-Lite SD365 is a plug-in addressable photoelectric smoke detector. It replaces the SD355 directly, keeping the same wiring and panel compatibility, with an updated optical chamber that meets UL 268 7th Edition.

Each detector takes one address on a Fire-Lite SLC loop and works with both LiteSpeed and CLIP protocols. Rotary decimal switches set the address. The unit has tamper resistance built in, a walk test with address display, and an insect-resistant screen on the chamber.

SD365 vs SD355: direct drop-in replacement

The SD365 is the official successor to the SD355. Wiring, base footprint, and panel programming stay the same. You swap the head and the system keeps running.

• Two-wire SLC loop, LiteSpeed and CLIP protocols
• Rotary decimal addressing
• Drop-in for SD355 with no rewiring
• Factory preset at 1.5% sensitivity, UL 268 7th Edition
• Tamper-resistant with insect-resistant screen
• Walk test with address display
• Removable cover for field cleaning
• White, ivory, or black finish

Where the SD365 is used

• Commercial buildings (offices, retail, hospitality)
• Schools and universities
• Healthcare facilities
• Industrial and warehouse environments
• Smooth ceilings under NFPA 72 spacing rules
• Duct applications (use the SD365R variant with a DNR/DNRW housing)