STI STI-1155NR Protective Cover with Horn and Spacer
Overview
The STI-1155NR is a polycarbonate protective cover assembly rated for both indoor and outdoor installation. Designed to prevent false fire alarm activations without restricting legitimate emergency pulls, the unit combines a clear tamperproof shield with an integrated piezo horn and spacer. Operating at 9VDC from an included alkaline battery, it fits standard manual fire pull stations and accommodates various mounting depths. UL listed for both U.S. and Canadian safety standards, the cover has proven effective for over 40 years across schools, hospitals, nursing homes, retail, and public buildings where accidental or intentional false alarms are a concern.
Compatibility
The STI-1155NR works with most standard manual pull station designs. The included spacer accommodates variations in door frame depth and pull station mounting configurations, making it suitable for both surface-mounted and recessed installations. For larger pull stations or non-standard frame geometries, the optional STI-3100 conduit spacer extends compatibility. The no-label configuration allows integrators to apply custom identification or instructions without factory relabeling.
Installation Notes
When covering an outdoor pull station, UL requires the underlying station to be listed for outdoor use. The cover itself includes closed-cell gaskets on weather models to seal against moisture and dust. Typical polycarbonate operating range is −40°F to +250°F (−40°C to +121°C). The 9VDC battery powers the piezo horn when the cover is lifted; remote-powered variants are available if hardwired power is preferred. Mount the spacer according to the pull station frame depth to ensure proper seal and lever engagement. Three-year warranty covers polycarbonate breakage under normal use; one-year coverage applies to electromechanical and electronic components.
What's in the Box
- 1x STI Stopper II protective cover assembly
- 1x integrated piezo horn
- 1x spacer for mounting depth adjustment
- 1x 9V alkaline battery
