Cleveland Controls AFS-227 Pressure Switch

The Cleveland Controls AFS-227 Pressure Switch is a high-performance, general-purpose proving switch engineered for critical HVAC, energy management, and light industrial applications. This adjustable differential pressure switch features a sensing range of 0.05" ± 0.02" w.c. to 12.0" w.c., providing technicians with a highly versatile field-adjustable solution for monitoring positive, negative, or differential air pressure. Built with a durable plated housing and a reliable silicone diaphragm, the AFS-227 is designed to withstand demanding environments, maintaining an operational temperature range from -40°F to 180°F. The SPDT snap-acting switch is rated for 15 amps non-inductive at 277 VAC, making it an ideal choice for air flow proving and fan status monitoring. For accurate calibration, the unit includes an adjusting screw protected by a removable guard. To ensure maximum sensitivity and the lowest specified set point, the Cleveland Controls AFS-227 must be mounted with the diaphragm in a vertical plane. The sample line connectors are designed to accept 1/4" OD rigid or semi-rigid tubing via integral compression ferrules and nuts, facilitating a secure and leak-free installation in building automation systems.

• Wide Adjustable Range: Provides field flexibility with a set point range from 0.05" to 12.0" w.c., reducing the need to carry multiple fixed-range switches.
• Versatile Application: Capable of sensing positive, negative, or differential pressure, making it suitable for fan air flow proving, filter monitoring, and frost detection.
• Industrial-Grade Build: Features a zinc-plated steel enclosure and a silicone diaphragm compatible with air and combustion by-products.
• High Electrical Capacity: The 15A SPDT switch handles high-current pilot duty and control applications without the need for auxiliary relays.
• Standardized Connections: Equipped with 6-32 screw terminals and 1/4" OD compression fittings for integration into existing HVAC control loops.

How do I adjust the set point on the AFS-227?
To calibrate the switch, turn the adjustment screw counter-clockwise until it stops, then turn it four full turns clockwise to engage the spring. Each subsequent full turn adjusts the set point by approximately 1.2" w.c. A digital manometer is recommended for precise field verification.

Can this switch be mounted in any orientation?
For optimal performance and to achieve the lowest specified set point, the switch must be mounted with the diaphragm in a vertical plane. Avoid mounting with the sample line connections pointing upward to prevent moisture or debris accumulation.

What tubing is recommended for the air sampling lines?
The AFS-227 is designed for 1/4" OD rigid or semi-rigid tubing such as copper, aluminum, or plastic. For runs exceeding 20 feet, 1/4" ID tubing is recommended to maintain signal integrity.

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.