System Sensor D4S Detector Sensor

The System Sensor D4S is a 4-wire photoelectric duct smoke detector sensor component designed specifically for integration with the D4120 duct smoke detector housing. Engineered for high-performance HVAC smoke detection, this replacement sensor head utilizes an advanced optical sensing chamber to detect combustion particles across a wide range of airflow speeds. It is optimized for low-flow duct smoke detection, maintaining reliable operation in velocities ranging from 100 to 4,000 feet per minute. The plug-in design allows for rapid field replacement without disturbing the existing conduit or wiring infrastructure, minimizing system downtime during routine maintenance. This sensor is critical for ensuring commercial HVAC fire safety compliance and provides robust false alarm rejection through sophisticated processing algorithms. When paired with the appropriate D4120 accessories, the D4S provides a stable sampling tube interface for accurate air quality monitoring within supply and return plenums.

Key Benefits for Technicians

• Broad Airflow Velocity: Operates effectively in duct environments from 100 FPM up to 4,000 FPM.
• Simplified Maintenance: Plug-in sensor head allows for tool-free replacement into the D4120 base.
• Nuisance Alarm Resistance: High-tolerance photoelectric chamber reduces service calls caused by dust and humidity.
• System Compatibility: Seamlessly integrates with 4-wire duct smoke detector configurations for fire alarm control panel reporting.
• Field Reliability: Built to withstand the environmental rigors of rooftop units and mechanical rooms.

Common Questions for HVAC Contractors

Is the D4S a standalone detector?
No, the D4S is the replacement sensor component only. It must be installed within a System Sensor D4120 duct housing to function as a complete smoke detection unit.

How do I test the D4S sensor during commissioning?
Testing can be performed using a calibrated canned smoke dispenser or via the magnet test point on the housing to verify the alarm relay activation and LED status.

Does this sensor support low-flow air applications?
Yes, the D4S is specifically rated for low-flow duct detection, ensuring it captures smoke even in high-efficiency systems with variable air volume (VAV) controls.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.