STI (SS2128EX-EN) Pneumatic Illuminated ; GREEN ; EMERGENC

The STI SS2128EX-EN is a green, illuminated, pneumatic-timer Stopper Station with an “EMERGENCY EXIT” label in English — a single-button request-to-exit station for delayed-egress doors and similar access-controlled exits. First, an occupant presses the recessed button. Then the integrated pneumatic timer holds the contact state for a fixed delay before automatically resetting. As a result, the connected door controller or access system processes the egress request without requiring an electrical reset signal.

What SS2128EX-EN is built for

Delayed-egress door hardware requires an occupant-initiated request that the building’s access control system can recognize and respond to. However, a plain pushbutton resets the moment the occupant lets go — too short for many controllers. Therefore, the SS2128EX-EN uses an adjustable pneumatic timer to hold the switch state for a programmed interval, then return to standby without consuming electrical power for the timing function.

Verified STI SS2128EX-EN specifications

• Series: STI Stopper Station SS2000 family — 2128 base = green, indoor only, flush or surface, pneumatic-timer reset
• Color: Green — the standard color for EMERGENCY EXIT / egress request controls
• Activation: Push button with integrated illumination
• Reset: Pneumatic timer (adjustable; no electrical power required for the timing function)
• Mounting: Flush or surface; indoor only
• Label: “EMERGENCY EXIT” in English
• Contacts: N.O. or N.C. SPST gold-plated contact blocks (interchangeable / replaceable)
• Contact rating: 6 A @ 600 VAC; 1 A @ 250 VDC
• Listing: UL Listed to U.S. and Canadian safety standards; complies with UL 2017
• Material features: Stainless steel backplate; 5VA flammability rating; polycarbonate working range -40°F to 250°F (-40°C to 121°C)
• Compliance: ADA Compliant push button
• Warranty: STI three-year guarantee against breakage of the polycarbonate under normal use (one year on electro-mechanical and electronic components)

Why pneumatic vs. electrical reset

Pneumatic-timer Stopper Stations need no electricity for the timing function — useful in security applications where dedicated reset wiring is impractical. In addition, the pneumatic timer is field-adjustable so installers tune the hold time to the door controller’s input requirements. Alternatively, the SS2039-series turn-to-reset stations require an operator to physically rotate the cover to reset; specify those when manual reset is the desired behavior. Furthermore, the SS21A2-series adds a built-in horn for higher-attention applications.

Application context

Delayed-egress doors, access-controlled exits in retail and healthcare, and similar managed-egress installations are the typical use case. However, the SS2128EX-EN is indoor only — for outdoor or weather-exposed installations, specify a different SS2000 series station with an outdoor rating. In addition, the SS2128EX-EN is not a fire alarm pull station and is not UL Listed for fire alarm initiating-device service.

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