Cleveland Controls FS-BO-178 Proving Switch

The Cleveland Controls FS-BO-178 is a heavy-duty, factory-calibrated air flow proving switch designed for critical monitoring in duct heaters, ovens, and sophisticated HVAC energy management systems. This model features a precise, non-adjustable set point of 0.05" w.c., ensuring consistent actuation on positive pressure rise without the risk of field tampering. Built with a rugged plated housing and a high-performance silicone diaphragm, the FS-BO-178 is engineered to withstand the demanding environments of industrial air handling. The normally open (NO) contact configuration provides a reliable "proof of flow" signal, integrated via standard 1/4" quick-connect terminals. For optimal field performance and to maintain the factory set point accuracy of ±0.02" w.c., this pressure sensing switch must be mounted with the diaphragm in a vertical plane. Its compatibility with air and non-corrosive combustion byproducts makes it a versatile solution for verifying blower operation and airflow safety across diverse ventilation control platforms.

• Consistent Performance: Factory-fixed set point at 0.05" w.c. eliminates the need for manual calibration and prevents drift over time.
• Industrial Durability: Robust construction and a silicone diaphragm support an operating temperature range of -40°F to 180°F.
• Simplified Installation: Features universal 1/4" spade terminals and is compatible with both rigid and flexible tubing for positive pressure sensing.
• Reliable Operation: Rated for a minimum of 100,000 cycles at maximum electrical load, ensuring long-term service in high-demand industrial HVAC applications.

• Can this switch be used for vacuum sensing? While designed primarily for positive pressure rise, the FS-BO series is typically utilized to sense pressure relative to the sampling probe location; always confirm your port configuration matches the intended differential.
• What is the proper mounting orientation? To ensure the differential pressure switch triggers at the specified 0.05" w.c., the unit must be installed with its diaphragm in any vertical plane.
• Is the set point adjustable in the field? No, the FS-BO-178 is a fixed set point switch. If your application requires variable trip points, an adjustable AFS series switch would be 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.