Cleveland Control AFS-227-121 Air Flow Switch

As an HVAC technician, you know that consistent pressure monitoring is the backbone of safe furnace and air handler operation. The Cleveland Controls AFS-227-121 is a professional-grade air flow switch and differential pressure sensing switch designed to tackle complex HVACR and energy management applications. This SPDT air pressure switch features a versatile field-adjustable set point range from .05" ± .02" to 12.0" w.c., allowing for precision calibration across positive, negative, or differential air pressure sensing. Built with a robust plated housing and a silicone diaphragm, this switch is compatible with air and combustion by-products that do not degrade silicone, making it a reliable furnace pressure switch replacement for industrial and commercial environments. The AFS-227-121 includes a comprehensive contractor kit with a 120-277Vac electrical rating and 1/4" quick-connect spade terminals to ensure straightforward integration into existing control circuits.

• Broad Adjustable Range: Field-calibrated set points from 0.05" to 12.0" w.c. provide maximum flexibility for varied static pressure requirements.
• Versatile Application: Capable of sensing positive, negative, or differential pressure, making it a universal choice for proving air flow.
• Contractor-Ready Kit: The -121 suffix designates a full installation kit, including necessary tubing and mounting hardware to reduce downtime on the job site.
• High Electrical Compatibility: SPDT contact arrangement supports 120V to 277V AC circuits, handling up to 1/2 PSI maximum pressure.
• Durable Construction: Zinc-plated housing and high-quality diaphragm ensure long-term performance in demanding HVACR environments.

How do I properly calibrate the set point?
To adjust the AFS-227-121, turn the adjustment screw counterclockwise until it stops, then turn it four full rotations clockwise to engage the spring. Use a digital manometer to confirm the exact set point during field calibration.

What is the best mounting orientation for this switch?
For maximum accuracy and to achieve the lowest specified set point, always mount the switch with the diaphragm in a vertical plane. Avoid mounting with sample line connections facing upward to prevent moisture or debris accumulation.

Can this switch be used with combustion air?
Yes, the Cleveland Controls AFS-227-121 is rated for use with air and combustion by-products, provided they are not chemically aggressive toward the silicone diaphragm material.

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.