Mcdonnell & Miller Series AF3 Air Flow Switches

The McDonnell & Miller AF3 is a general-purpose low-velocity flow switch designed for applications where an economical switch is needed. It is commonly used in HVAC, water treatment, and industrial piping systems to detect flow or no-flow conditions in ducts or pipes of 8 inches (203 mm) minimum size.

The AF3 flow switch features a paddle that fits a minimum duct size of 8 inches (203 mm). It is designed for low-velocity applications and includes two electrical connections. Note that the manufacturer lists this model as obsolete or discontinued, so availability may be limited.

You can source the McDonnell & Miller AF3 flow switch through 3G Electric in Singapore. We handle logistics, customs clearance, and delivery to your facility. Contact us for current pricing and lead time, as this model is listed as discontinued by the manufacturer.

Install the AF3 flow switch in a horizontal pipe section with the paddle oriented correctly for flow direction. Ensure the minimum duct size of 8 inches (203 mm) is met. Follow standard wiring practices for the two electrical connections and verify proper operation after installation. Consult the manufacturer's manual for specific torque and clearance requirements.