STI STI-3150 Weather Stopper Electromagnetic Strike
Overview
The STI-3150 is a 9VDC electromagnetic strike engineered for access control door installations where environmental durability and fire code compliance matter. This is a purpose-built component for integrators who need predictable holding force in outdoor or semi-protected door frames without field-fabricating spacers or hunting down separate fire labels. The integrated spacer and fire rating label arrive ready to install—reducing assembly time and reducing the risk of missing a code requirement during commissioning.
Key Features
- 9VDC operation: Draws power from standard access control power supplies and secondary battery backup systems common in integrator deployments. This voltage is typical across door strike installations, so you won't need a dedicated transformer or custom PSU specification.
- Electromagnetic strike technology: Provides reliable holding force suitable for high-traffic security applications. When de-energized, the door unlocks—no moving parts to stick or corrode in outdoor environments.
- Integrated spacer: Eliminates the need to source or fabricate shim material on-site. The spacer is engineered into the housing, saving labor time during frame preparation and reducing assembly variation.
- Fire label affixed: Marked and labeled for fire-rated door installations. Meets jurisdictional fire code documentation requirements without requiring a separate label order or field application.
- Weather-sealed enclosure: Designed to withstand outdoor moisture and temperature swings. Suitable for covered exterior frames, warehouse loading doors, and semi-protected industrial entry points where standard indoor strikes would corrode or fail.
- Standard access control integration: Compatible with typical door controllers, REX (request-to-exit) sensors, and badge readers. No proprietary wiring or protocol required—integrates into conventional hardwired access systems.
Integration and Deployment Context
The STI-3150 fits into access control architectures where the door frame itself needs protection from weather. If you're deploying electromagnetic strikes on an exterior canopy or loading dock, environmental durability is not optional. The integrated spacer and fire label streamline the approval and installation process—especially in facilities where code compliance documentation must be visible and accessible during inspections.
Pair with a standard 12V or 24V access control power supply (the STI-3150 runs at 9VDC, so verify your PSU includes a 9VDC tap or plan a buck converter). Confirm door frame mounting surfaces are clean and flat; the spacer compensates for minor frame variation, but gross misalignment still requires shim adjustment.
When to Choose a Different Model
If your installation is fully indoors with no moisture exposure, a standard electromagnetic strike (without the weather sealing and fire label) will be lower cost. If you need a magnetic lock instead of a strike—for example, on a glass storefront or low-traffic administrative door—evaluate the STI magnetic lock family separately. If the door requires delayed egress or monitored force feedback, confirm the STI-3150's fail-safe behavior aligns with your access control logic before commissioning.
Frequently Asked Questions
Q: What happens to the door when power is cut or interrupted?
A: The STI-3150 is a fail-safe strike—loss of power releases the door. This is intentional for life safety. If you need the door to remain locked during a power failure, you'll need a fail-secure strike and a battery backup PSU at the controller, not at the strike itself.
Q: Can I install the STI-3150 on a wooden door frame?
A: Yes, provided the frame is solid and the mounting surface flat. The integrated spacer helps absorb minor frame irregularities, but you must still follow STI's installation template and torque specifications. Weak or rotted wood will not hold the strike securely.
Q: Does the fire label need to be re-certified or replaced?
A: The fire label is affixed at manufacturing and is not field-replaceable. If the label is damaged or becomes illegible, contact the manufacturer or your distributor for a replacement unit. Do not attempt to reapply or remove the label yourself.
Q: Is the STI-3150 compatible with all door controllers?
A: The STI-3150 is a simple electromagnetic device with no embedded logic. It integrates with any standard access control system that outputs a 9VDC relay command. Verify your controller's power supply includes a 9VDC output; if not, you'll need a separate buck converter or dedicated 9VDC PSU tap.
Q: What is the holding force of the STI-3150?
A: Holding force specifications are not provided in the available technical documentation. Contact the manufacturer or your local distributor with the model number to request force ratings in pounds or newtons.
Q: Can the STI-3150 be used in a freezing climate?
A: The unit is weather-sealed and rated for outdoor use, but extreme cold or salt spray may affect longevity over time. If your site is coastal or subject to de-icing chemicals, inspect the strike annually and consider a protective shroud or housing extension.
Ted PerryPerspective based on aggregated IP Security Depot and affiliated engineering team experience.
The STI-3150 is a straightforward choice if you're looking to save labor and compliance headaches on a weather-exposed door frame installation. The integrated spacer and fire label eliminate two common field tasks—frame shimming and label hunting—and arrive pre-assembled. At 9VDC, it's a standard voltage across most access control platforms, so power integration is typically a non-event.
Technical Highlights:
- 9VDC electromagnetic operation: Matches the power rail on most standard access control PSUs. No custom transformer or isolated supply needed. Fail-safe behavior (de-energized = unlock) is inherent to the electromagnetic design—no moving parts to jam or corrode in outdoor moisture.
- Integrated spacer: Saves 30–45 minutes of frame prep and shimming per installation. Reduces variation in strike seating, which translates directly to more reliable holding force and fewer callback service calls due to misalignment.
- Factory-affixed fire label: Eliminates the risk of missing or mis-applying a fire rating during commissioning. Code inspectors can verify compliance by visual inspection without needing to trace paperwork.
- Weather-sealed enclosure: Rated for semi-protected outdoor environments (covered canopies, loading docks, sheltered frames). Not suitable for direct rain splash or submersion, but adequate for most warehouse and industrial perimeter doors.
Deployment Considerations:
- Confirm your access control PSU provides a 9VDC output. If it only offers 12V or 24V on the strike rail, you'll need a separate 9VDC buck converter or a dedicated power tap—this is a frequent oversight during design review.
- The fire label is factory-installed and not field-serviceable. If it becomes damaged or faded, order a replacement unit rather than attempt a repair. This is a code compliance item, so don't patch or workaround.
- Fail-safe behavior means the door releases on power loss. If your application requires fail-secure operation (door stays locked during a power event), this is not the right strike. You'll need a different device class and a UPS-backed power supply.
- Weather sealing is good for outdoor covered areas but not for direct rain exposure or salt spray. On a coastal or high-spray site, plan for annual inspection and consider adding a protective shroud.
Best fit: warehouse loading doors, covered building perimeters, industrial entry frames where code compliance must be visible and labor efficiency matters. Skip this model if the installation is indoors or if you need fail-secure behavior—choose the appropriate strike variant from the STI electromagnetic family.
