Schneider Electric (Barber Colman) 2390-501 Gradual Switch

The Schneider Electric 2390-501 Gradual Switch is a precision-engineered pneumatic manual positioner designed for proportional control in commercial HVACR systems. Utilizing a reliable manual dial, this device allows technicians to modulate output pressure from 0 to 20 psig, providing direct control over pneumatic actuators, dampers, and valves. Built for durability and accuracy, the 2390-501 operates with a 20 psig main air pressure and delivers an 8 SCFH air capacity with a low air consumption rate of 29 SCIM. Its design simplifies field installation with integrated barbed nipples compatible with both 1/4" O.D. and 5/32" I.D. plastic tubing. For contractors troubleshooting legacy Barber Colman pneumatic systems, this gradual switch serves as a rugged, direct-replacement component for maintaining proportional pneumatic control in air handling units and mechanical rooms where precise manual overrides or setpoint adjustments are required.

• Precise Proportional Action: Delivers a linear 0 to 20 psig output signal for accurate modulation of ending devices.
• Low Air Consumption: Efficient 29 SCIM consumption reduces the overall load on the pneumatic compressor system.
• Versatile Connection Porting: Features barbed fittings that accommodate standard HVAC tubing sizes for rapid field piping.
• Field-Proven Reliability: Originally part of the Barber Colman line, this switch is a staple for maintaining vintage and modern pneumatic control loops.

How do I calibrate the output of the 2390-501?
Technicians should use a calibrated 0-30 psi gauge at the output port. Adjust the dial and verify that the output pressure matches the scale plate markings, ensuring the main air supply is stable at 20 psig.

Can this switch be used with 30 psig main air?
The standard operating pressure for the 2390-501 is 20 psig. Exceeding the rated main air pressure may affect the accuracy of the proportional output and increase wear on internal components.

What are the mounting requirements for this manual positioner?
The device is designed for panel mounting, providing a clean interface for operators to adjust static pressure setpoints or damper positions from a central control board.

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.