Vulcain VA301IRFSR404A Sensor

The Vulcain VA301IRFSR404A (also identified by part number M-509255 or S301-IRF-R404A) represents the industry standard for high-precision R404A refrigerant gas detection in mechanical rooms and chiller plants. This infrared refrigerant sensor utilizes dual-channel sensing technology to mitigate signal drift and cross-sensitivity, providing a stable 0–1,000 ppm measurement range with a 1 ppm resolution. Engineered specifically for seamless integration with the Honeywell 301EM controller, this unit ensures your facility maintains strict compliance with ASHRAE 15 and B-52 safety codes. The rugged ABS-polycarbonate housing is designed for "at the source" monitoring; for optimal performance, technicians should mount this refrigerant leak detector low on walls or directly to chiller pads, as R404A is heavier than air. With its 4-20mA signal output and RS-485 Modbus communication capabilities, it provides real-time data to building management systems, facilitating prompt alarm activation and mechanical ventilation control during critical leak events.

• Precise Infrared Sensing: Advanced Nadir IR technology provides accurate R404A detection with a 60-second T90 response time.
• System Integration: Native RS-485 Modbus and 4-20mA current loop compatibility for effortless pairing with 301EM controllers and BAS networks.
• Enhanced Stability: Dual-beam infrared source minimizes the need for frequent gas sensor calibration and prevents false alarms from humidity or temperature fluctuations.
• Code Compliance: Essential for meeting ASHRAE Standard 15 and International Mechanical Code requirements in commercial chiller rooms.
• Durable Construction: NEMA-rated enclosure stands up to the vibration and thermal cycles found in heavy-duty HVAC mechanical rooms.

Is the VA301IRFSR404A a direct replacement for the M-509255?
Yes. This sensor is the direct manufacturer replacement part for the Vulcain M-509255 and is technically identical to the S301-IRF-R404A. It is designed to work exclusively with the 301EM and 301C series controllers.

Where should this R404A sensor be mounted for maximum effectiveness?
Since R404A refrigerant is heavier than atmospheric air, the sensor must be installed 12 to 18 inches above the floor. Avoid placing it in areas of high airflow or "dead zones" where refrigerant might not naturally accumulate.

Does this unit require a separate power supply?
The VA301IRFSR404A typically receives its 12 VDC power directly from the 301EM controller via the communication bus. Ensure you verify the total power load on your controller if running multiple remote gas sensors on a single loop.

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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.