White-Rodgers 770-1 Air Switch

The White-Rodgers 770-1 Air Switch is a versatile, field-adjustable differential air pressure switch designed for critical proving applications in HVACR systems. Featuring a SPDT (Single Pole Double Throw) snap-action switch, this unit can be configured to actuate on positive, negative, or differential pressure. Unlike standard sail switches that are prone to mechanical fluttering, the 770-1 utilizes a robust enclosed diaphragm design that remains stable under shock and vibration. With a wide adjustable operating range of 0.05" to 12.0" W.C., it is the go-to component for proving airflow in electronic air cleaners, humidifiers, and duct strip heaters. It is also suitable for monitoring draft in natural draft boilers or proving inducer motor operation in high-efficiency gas-fired units. The 770-1 supports 15 Amp electrical ratings and can be mounted in any orientation except upside down, ensuring flexible integration into existing mechanical room layouts. Each unit is furnished with a 12-inch length of 1/4" O.D. flexible tubing, nuts, and self-aligning ferrules for a reliable sample line connection.

• Reduced Callbacks: Enclosed diaphragm design eliminates the fluttering and mechanical failures common with traditional sail switches.
• Broad Compatibility: The SPDT switch action allows for normally open or normally closed wiring, making it compatible with alarm circuits and safety interlocks.
• Precision Tuning: Field-adjustable set point from 0.05" to 12" W.C. ensures accurate airflow proving across various static pressure environments.
• Rugged Temperature Rating: Engineered to operate reliably in ambient temperatures ranging from -40°F to 180°F.
• Easy Installation: Includes 1/4" O.D. tubing and compression fittings for immediate connection to the sensing probe or heat exchanger.

How do you adjust the pressure set point?
The set point is adjusted by turning the knurled knob. Clockwise rotation increases the pressure required to actuate the switch. It is recommended to use a manometer during commissioning to verify the exact trip point for induced draft or positive pressure applications.

Can this switch be used to monitor filter status?
Yes. By plumbing the 770-1 as a differential pressure switch across the filter bank, it can trigger an indicator light or BMS alarm when the static pressure drop exceeds the set point, signifying a dirty filter.

What is the proper mounting orientation?
The diaphragm should be in a vertical plane for maximum accuracy. The 770-1 can be mounted in any position except with the sample line connectors facing upward (upside down), as this can allow moisture or particulates to accumulate on the diaphragm.

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.