the 8021206021 is designed to sense the difference between two pressure sources

ensure you are utilizing the VS series equivalent with a high-temperature rated actuator

When performing a York S1-328-12454-000 swap

if the motor is humming but not starting

this component is a drop-in replacement for worn NCO-117U4127 assemblies

Schneider Electric (Barber Colman) AL-161-4 Switching Valve Refrigerant the 8021206021 is designed toThe Schneider Electric (Barber Colman) AL 161 4 Switching Valve is a robust 3 way pneumatic switching valve engineered for critical air distribution in dual pressure HVAC systems. This unitary valve is designed to facilitate seamless central supply air changeover, operating reliably within an 8 13 psi pressure range. Featuring 1 2 inch FNPT body connections and a 1 8 inch FNPT actuator port, the AL 161 4 ensures high capacity throughputrated at 25,920