The Cleveland Controls RFS-4100-040 is a heavy-duty, field-adjustable differential air pressure switch designed for critical proving applications in HVAC and Energy Management Systems. Engineered to detect positive, negative, or differential pressure, this airflow proving switch features a sensing range of 0.15" WC to 5.0" WC. The internal silicone diaphragm and snap-acting SPDT switch provide reliable performance, rated for 300 VA pilot duty at 115 to 277 VAC. For precise field calibration, the adjustment screw allows for approximately 0.61" WC per full turn, enabling technicians to dial in set points for specific system requirements. The zinc-plated steel housing includes tri-barb connectors that accommodate 3/16", 1/4", and 5/16" ID flexible tubing, ensuring high HVAC part compatibility across various pneumatic setups. To maintain accuracy and prevent set point drift, the unit must be surface-mounted in a vertical plane using the integrated strap bracket. Key Benefits: Versatile Sensing: Capable of monitoring positive, negative, or differential air pressure within a single adjustable pressure switch unit. Flexible Installation: Integrated tri-barb sample line connectors eliminate the need for extra adapters when using various tubing sizes. Durable Construction: Zinc-plated housing and NEMA 1 enclosure rating protect the internal calibration spring and diaphragm from harsh mechanical environments. High Electrical Capacity: Robust 15-amp non-inductive rating at 277 VAC satisfies most commercial and industrial electrical load requirements. Common Questions: Can this switch be mounted horizontally? No, the RFS-4100-040 must be mounted with the diaphragm in a vertical plane to maintain its calibrated operating set point and prevent gravity-induced errors. How do I verify the exact set point during installation? While the adjustment screw provides 0.61" WC per turn, a digital manometer should always be used at the "H" and "L" ports to confirm the actual trip point. Is this suitable for combustible gases? This switch is specifically designed for use with inert, dry air; it is not intended for use with combustible or corrosive gas media. This item is not eligible for free shipping. 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.
