The GST Model I-9105R intelligent reflective infrared beam smoke detector is engineered to operate seamlessly within both centralized addressable loop architectures and decentralized conventional fire alarm infrastructures. Its dual-mode functional capability allows electrical contractors and system engineers to implement the unit as a native addressable field device or as a relay-monitored conventional optical beam sensor across large-scale facilities.
GST Intelligent Fire Alarm Control Panel Integration
When operating in addressable mode, the I-9105R connects directly to proprietary digital signaling loops of GST intelligent fire alarm control panels. System communications and telemetry are fully supported across standard two-wire loops on the following panels:
- GST200-2: Intelligent Fire Alarm Control Panel
- GST5000: Modular Intelligent Fire Alarm Control Panel
- GST-IFP8: Multi-Loop Intelligent Fire Alarm Control Panel
The detector interfaces with the addressable loop via non-polarized terminals Z1 and Z2, operating within a signaling loop voltage range of 15VDC to 28VDC (nominal 24VDC). Field addressing supports numerical allocations from 1 to 242, enabling seamless integration into multi-node industrial fire detection topologies without occupying multiple physical addresses.
Conventional Fire Alarm Control Panels and Relay Interfacing
For installations utilizing conventional fire alarm control panels or third-party building management platforms, the I-9105R incorporates onboard dry auxiliary relay contacts for complete signal reporting without direct loop communication:
- Alarm Relay Output (Terminals K11 & K12): Normally open (NO) dry contact rated at 28VDC / 2A contact capacity, closing immediately upon confirmed smoke obscuration.
- Fault Relay Output (Terminals K21 & K22): Normally closed (NC) dry contact that opens upon beam blockage, optical path misalignment exceeding tolerance, supply voltage failure, or internal microprocessor fault.
These hardwired dry contacts allow direct wiring into conventional zone circuits, zone monitor input modules, or supervisory inputs on standard fire and automation hardware.
Commissioning Tool and Programmer Compatibility
Device addressing and site-specific optical sensitivity parameters are configured using the GST P-9910B hand-held programmer. Utilizing this field programming unit, commissioning engineers can electronically assign the digital address (range 1–242) and configure the optical beam sensitivity threshold prior to or following mechanical installation, eliminating manual DIP switch adjustments.
Power Infrastructure and Cabling Requirements
The I-9105R requires an external 24VDC operating power supply delivered over a separate pair of conductors. Operating current characteristics must be calculated into system power supply sizing and battery backup calculations:
| Parameter | Specification / Requirement | Terminal Connection |
|---|---|---|
| Loop Operating Voltage | 24VDC (15VDC to 28VDC) | Z1, Z2 (Non-polarized) |
| Field Address Range | 1 to 242 (Configured via GST P-9910B) | Via Loop / Programmer Port |
| Auxiliary Power Supply | 24VDC (±10%) | D1, D2 (Non-polarized) |
| Standby Current | 12 mA | Power Terminals D1, D2 |
| Alarm Current | 22 mA | Power Terminals D1, D2 |
| Fire Alarm Output | Normally Open Dry Contact (28V / 2A) | K11, K12 |
| Fault Output | Normally Closed Dry Contact | K21, K22 |
| Conductor Sizing | Minimum 1.0 mm² fire-rated cable | All Terminal Blocks |
Optical Pathway and Reflector Hardware Configuration
The transceiver unit pairs with passive optical honeycomb reflector mirrors to establish a functional infrared path between 8 meters and 100 meters, covering a maximum monitoring area of 1,400 m² with a lateral monitoring width of up to 14 meters. The optical arrangement requires specific reflector quantities based on physical path length:
- Short-to-Medium Path (8 m to 40 m): Requires exactly 1 passive honeycomb reflector mirror mounted directly opposite the transceiver.
- Long Path (40 m to 100 m): Requires 4 passive honeycomb reflector mirrors installed together in a square matrix configuration directly opposite the transceiver.
The unit supports mechanical mounting onto a standard two-gang electrical back box or direct surface mounting to structural walls using screw plugs. Optical alignment accommodates an adjustment angle of -6° to +6° with an operational angular misalignment tolerance limit of ±0.5°, compliant with BS EN54 Part-12 standards.
