Built to exacting Armstrong Air specifications

functioning as a normally open contact that closes once the draft inducer motor generates sufficient negative pressure

Anything consistently below 1

designed to eliminate parallax errors during manual readouts

including Luxaire and Coleman models

Functional Devices RIB RIB2421SB Relay Built to exacting Armstrong AirThe Functional Devices RIB2421SB is a heavy duty, pre packaged 20 Amp enclosed relay engineered for high demand HVACR and industrial energy management systems. This SPDT relay features a multi voltage coil that accepts 24VAC DC, 120VAC, and 208 277VAC, providing a versatile solution for varying control circuit requirements without the need for multiple stocked parts. Designed for direct BAS and lighting control, the RIB2421SB relay includes an