Exclusive Availability and Integration Lifecycle via SKYRS Pakistan
The OH921 Series consists of high-performance, intelligent addressable multi-criteria detection devices designed to provide rapid fire event recognition while offering industry-leading immunity to nuisance or false alarms. By seamlessly integrating an optical chamber with a precision solid-state thermal sensor, the OH921 uses an internal neural network to cross-examine environmental signatures, making it the premier choice for complex institutional, commercial, and industrial deployments
The OH921 line is categorized by specialized application profiles and regional configurations optimized for the Pakistan infrastructure market:
OH921-S (Standard Commercial Variant): The default configuration. Pre-programmed for clean, baseline indoor spaces such as modern office buildings, retail spaces, and hospitality lobbies.
OH921-D (Integrated Duct/HVAC Variant): Specifically tuned via its internal algorithm to handle high-velocity airflow environments without losing sensitivity, eliminating false alarms caused by fast-moving dust or moisture.
OH921-X (Class-X Isolation Variant): Incorporates advanced ISOtechnology™ for True-Class-X Signaling Line Circuits (SLC). Ideal for critical infrastructure, maintaining full isolation loop integrity and locating exact branch faults even under severe short-circuit conditions.
| Parameter | Specification Rating |
| Operating Voltage | 15 to 32 VDC |
| Standby Current | 250 µA (Typical) |
| Maximum Alarm Current | 5.0 mA |
| Thermal Sensing Parameters | Fixed 135°F (57°C) or Rate-of-Rise at 15°F/min (8.3°C/min) |
| Status Indication | Tri-color LED (Green, Yellow, Red) with 360-degree visibility |
| Communication Protocol | Addressable, two-wire loop (SureWire™ Polarity Insensitive) |
| Operational Temperature | 32°F to 100°F (0°C to 38°C) |
| Relative Humidity Range | 10% to 93% RH (Non-condensing) |
| Agency Compliance | UL 268 7th Edition, NFPA 72, CSFM |
The physical deployment process must be handled by trained engineers to guarantee strict compliance with safety codes and structural floor plans.
Base Mounting: Secure an approved surface-mounting base (Model DB-11, DB-11E, or DB2-HR) onto a standard 4-inch octagonal, square, or single-gang electrical enclosure box.
Loop Wiring: Connect the two-wire signaling line circuit (SLC) to the screw-clamp terminal blocks on the base. Thanks to polarity-insensitive engineering, standard T-tapping is permitted for Style 4 (Class B) field layouts. Maintain strict loop continuity when leveraging Class-X configurations.
Chamber Protection: Leave the protective plastic dust cover on the device head during the entire construction and wiring phase. Remove the dust cover only when the building is entirely clean and ready for final commissioning.
Insertion: Align the OH921 detector head with the mounting base, press inward gently, and rotate the head clockwise until it securely seats into the self-wiping contact junctions.
Programming the device relies on microprocessor-driven software parameters rather than primitive manual dials.
Electronic Addressing: Utilize the dedicated portable Device Programmer / Loop Tester (Model DPU) to write a unique electronic address directly into the detector’s microcomputer chip prior to twisting it into the base.
Profile Selection: Through the Fire Alarm Control Panel (FACP) software interface, assign the targeted application profile (Standard or Duct) to individual device addresses depending on their specific physical placement.
System Diagnostics: Once the loop is energized, verify that the device initiates its automatic self-monitoring cycle (executed internally every 10 seconds). The tri-color LED will flash Green to confirm normal operations, Yellow to indicate a fault or sensitivity drift, and Red for an active alarm state.
CRITICAL PROCUREMENT NOTE: All variants of the OH921 Multi-Criteria Detector Series—along with authorized mounting bases, certified engineering software tools, and direct manufacturer-backed component support—are available exclusively through SKYRS in Pakistan.
SKYRS provides end-to-end management, covering the initial hardware supply, local technical deployment, system-level panel configuration, and certified structural handover for all enterprise security and fire infrastructure projects across Pakistan.
