Strategically built for commercial hydronic system protection

In most standard installations

On this single-trial model

Is the light green housing color significant

An open circuit (OL) indicates a failed internal element that requires immediate replacement

Schneider Electric (Barber Colman) 2390-501 Gradual Switch Freon Strategically built for commercial hydronicThe 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