The SPS is used to sense duct pressure and control the modulating damper to provide more accurate control of by-pass air in zoned system. Its two fixed sensors are factory set at 0.2 in and 0.3 in S.P. The modulating by-pass damper is wired to open above 0.3 in and close below 0.2 in. The damper stops between these pressures.
3 A resistive at 120 VAC|125 VA at 125 VAC|28 VA pilot duty at 24 VAC
Zonefirst Static Pressure Switch, SPST Switch, Snap Acting Electronic, 0.2 in WC Close, 0.3 in WC Open Pressure