HONEYWELL S437A1025 Switch with 1 1/2 in. x 4 in. Sail. The S437 Sail Switches respond to the air velocity in heating or warm air ducts, such as used in farm crop dryers. The switch completes a 24V or line voltage burner control circuit only when the blower or fan has produced a predetermined air velocity.
• Micro Switch SPST snap switch is operated by metal sail inserted in an air stream.
• Sail can trimmed to one-half the original size to double the velocity required to close the snap switch contacts.
• Switch differential can be manually adjusted by turning a knurled knob on the snap switch.
• A conduit knockout is located on each end of the case for wiring convenience.