STI STI-1250 Flush Mount Electric Strike with Fire Label
The STI STI-1250 is a flush mount electric strike engineered for fire-rated door frame installations where weatherproofing and access control integration are required. Operating at 9VDC, this strike fits standard cavity installations and ships without horn, making it suitable for environments where silent operation is essential or audio feedback is managed through a separate signaling system.
Key Features
- Flush Mount Design: Installs directly into standard door frame cavities, requiring no surface-mounted housing. This means cleaner aesthetics and reduced visible hardware — important in security-conscious facilities where discrete equipment is preferred.
- 9VDC Operation: Low-voltage DC power simplifies control system integration and reduces power draw on building circuits compared to AC-powered alternatives. Standard 9VDC supplies are available from most access control manufacturers.
- Fire-Labeled Certification: The STI-1250 carries fire label certification, a requirement for life-safety compliance on fire-rated door assemblies. This avoids costly retrofit work during inspection — verify your local AHJ and door frame manufacturer compatibility before purchase.
- No Horn Configuration: Ships without integrated horn or buzzer. Useful for silent-operation environments (hospitals, libraries, secure facilities) or where the access control system handles all audio feedback separately. If audio feedback is critical to your deployment, plan integration with an external sounder or gate alarm module.
- Weather Stopper® Technology: Weatherproofing provisions protect against environmental exposure, extending service life in semi-protected installations such as loading docks or vestibule entries. Not rated for full outdoor or submersion exposure — verify your door frame location matches the environmental rating.
- Access Control System Compatibility: Integrates with standard 9VDC access control architectures (reader controllers, proximity/keypad systems, electromechanical locks). Confirm voltage and polarity requirements with your control system before wiring.
Integration & Compatibility
The STI-1250 is designed for retrofit or new installation into standard North American door frame cavities. Compatibility depends on frame dimensions and existing strike pocket geometry — measure your door frame opening and compare to manufacturer specifications before ordering. Verify that your access control system supplies stable 9VDC output with sufficient current capacity for the strike solenoid. If your system uses different voltage (12VDC, 24VDC) or AC power, this model is not compatible without a voltage converter — a cost and failure-point to avoid.
Because this strike carries fire-label certification, installation must comply with fire code requirements and door assembly documentation. Work with a qualified locksmith or security integrator familiar with fire-rated door assemblies to ensure proper installation and inspection sign-off.
Deployment Considerations
The no-horn design means you must provision separate audio feedback if building occupants need audible confirmation of door strikes. Consider pairing with a gate alarm or external sounder on the same 9VDC circuit. Additionally, the fire-label rating limits this strike to use in fire-rated assemblies — do not use on standard (non-rated) doors where fire compliance is not required, as the strike may be over-spec'd for the application.
Frequently Asked Questions
Q: Is the STI-1250 suitable for outdoor or high-moisture environments?
A: The Weather Stopper® design provides weatherproofing for semi-protected areas like loading docks and vestibules. For full outdoor exposure or high humidity (parking structures, greenhouses), verify environmental rating limits with the manufacturer datasheet. Submersion or direct hose-down is not supported.
Q: Can I use the STI-1250 with a 12VDC or 24VDC access control system?
A: No. The STI-1250 is rated for 9VDC operation only. Applying 12VDC or higher will damage the solenoid. If your system operates at a different voltage, you will need a compatible strike or a step-down voltage converter — adding cost and complexity.
Q: What happens if I need audio feedback when the door strikes?
A: The STI-1250 ships without horn. You must integrate an external sounder, buzzer, or gate alarm module on the same control circuit if audio feedback is required for user confirmation or building code compliance.
Q: Does the fire-label certification mean this strike must be used on fire-rated doors?
A: Fire-label certification indicates the strike meets fire code requirements for rated door assemblies. You can use it on standard doors, but it may be over-spec'd and more expensive than necessary. Verify your local fire code and door frame requirements before purchasing.
Q: How do I know if the STI-1250 will fit my door frame?
A: Flush mount strikes require a cavity pocket in the door frame. Measure the width, depth, and height of your existing strike cavity and compare to the manufacturer dimensions. If you're unsure, consult a locksmith or review the door frame documentation from your frame supplier.
Jerry TildsenPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The STI-1250 is a solid choice for fire-rated door assemblies where voltage constraints and silent operation are part of the spec. The 9VDC requirement is the critical gating factor — if your access control system doesn't natively supply 9VDC, this strike demands either a compatible controller or a voltage converter. Either adds cost and a potential failure point that auditors will flag during commissioning.
Technical Highlights:
- 9VDC Solenoid Locking: Low voltage reduces wiring complexity and power draw, but locks you into compatible control system hardware. Verify your panel supply voltage during design phase — a mismatched voltage is not recoverable without a retrofit.
- Flush Mount Cavity Design: Requires exact frame pocket dimensions for a clean fit. Oversized or undersized cavities force workarounds (shims, adapters) that compromise fire-label integrity and may void compliance certification.
- Fire-Label Certification: Mandatory for life-safety compliance on rated assemblies, but adds cost versus non-rated strikes. If you're securing a standard (non-rated) door, consider whether the certification justifies the price premium.
Deployment Considerations:
- No integrated horn means you must plan separate sounder integration if building occupants need audible strike feedback — a detail often overlooked during initial specification.
- Weather Stopper® weatherproofing is suitable for semi-protected vestibules and loading docks, not continuous outdoor exposure. Verify door location and environmental exposure before purchase.
Position the STI-1250 for fire-rated entry doors in buildings where the existing access control system already supplies 9VDC and silent operation is acceptable. This eliminates integration risk and avoids retrofit surprises during inspection.
