The Johnson Controls AFS-460 is a heavy-duty air pressure sensing switch designed for critical HVAC airflow proving and energy management applications. Built with a plated housing and a durable silicone diaphragm, this differential pressure switch facilitates precise monitoring of positive, negative, or differential air pressure. It features a field-adjustable set point range of 0.40" ± 0.06" to 12" w.c., allowing for granular control in high-performance duct systems. As a manual reset pressure switch, it requires direct operator intervention after actuation, ensuring that system faults are addressed before resuming operation. The SPST normally closed contact arrangement is rated for 15 Amps at 125, 250, or 277 VAC, making it compatible with a wide range of industrial control circuits. For a reliable seal, the unit utilizes 1/4" OD sample line connections with integral compression ferrules. Engineers and technicians should prioritize vertical mounting to maintain the lowest specified operating parameters and avoid moisture accumulation in the sample lines. Key Benefits Manual Reset Feature: Enhances system safety by requiring a technician to physically reset the proving switch after an air pressure trip. Variable Set Points: Offers a wide adjustable differential pressure range from 0.40" to 12" w.c. to accommodate various duct static pressures. Durable Construction: The rugged plated metal housing protects internal snap-acting switches and the 1/2 psi maximum pressure rating ensures HVAC switch longevity. Easy Integration: Standard 1/2" conduit connection and screw-top terminals with cup washers simplify standard field wiring. Common Questions What is the proper mounting orientation for the AFS-460? To reach the lowest specified air pressure sensing set point, always mount the switch with the diaphragm in a vertical plane. Avoid mounting with sample line connections facing upward to prevent condensation buildup. Can I use this switch for negative pressure sensing? Yes, the AFS-460 is versatile. For negative pressure, connect the sample line to the low-pressure inlet (L) while leaving the high-pressure inlet (H) open to the atmosphere. What type of tubing is compatible with the connections? The unit is designed for 1/4" OD rigid or semi-rigid tubing via the included 1/4" compression fittings. For flexible tubing, an optional adapter is typically required. 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.
