Johnson Controls AFS-262 Air Flow Switch

The Johnson Controls AFS-262 Air Flow Switch is a heavy-duty, general-purpose differential pressure sensing switch designed for critical HVAC and Energy Management applications. This field-adjustable unit allows contractors to establish precise air pressure proving within a range of 0.05 to 2.0 inches WC, making it a versatile solution for monitoring positive, negative, or differential pressure across coils, filters, and fans. Housed in a durable plated casing, the internal silicone diaphragm and snap-acting SPDT (Single Pole Double Throw) switch ensure reliable performance even when exposed to air or combustion by-products. The AFS-262 features 1/4 inch OD metallic tubing connections equipped with integral compression ferrules and nuts for a secure, leak-proof fit. For optimal sensitivity and to achieve the lowest specified set point, the device must be installed with the diaphragm in a vertical plane. The enclosure includes 1/2 inch conduit access to protect the screw-type terminals, supporting seamless integration into industrial control loops or alarm circuits.

• Adjustable Set Point Range: Offers a field-calibrated range from 0.05 to 2.0 inches WC for precise HVAC airflow monitoring.
• Versatile Sensing Capabilities: Engineered to accurately detect differential pressure, positive pressure, or static negative pressure.
• Rugged Component Design: Features a silicone diaphragm and a plated housing rated for 100,000 cycles at maximum electrical load.
• Standardized Connections: Utilizes 1/4 inch OD compression fittings and 1/2 inch conduit openings for straightforward technician field installation.
• High Electrical Capacity: SPDT contacts rated for 15 amps non-inductive at 277 VAC, suitable for various pilot duty and control applications.

How do I change the set point on the AFS-262?
The set point is adjusted by turning the internal calibration screw. To ensure accuracy for pressure switch calibration, use a digital manometer while adjusting the screw (clockwise to increase, counter-clockwise to decrease) to match the required system inches of water column.

What is the proper mounting orientation for this switch?
For AFS-262 installation, the unit must be mounted vertically. This prevents the weight of the diaphragm from affecting the set point, ensuring the switch trips at the calibrated pressure differential.

Can this be used for combustion air proving?
Yes, the AFS-262 is rated for air and combustion by-products that do not degrade silicone, making it suitable for draft proving in furnace and boiler applications.

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.