Always cross-reference the original part number or measure the 3/4" bore and wheel dimensions before ordering

When replacing a Fasco D653

this valve provides the precise regulation required to maintain thermal efficiency and safe operating parameters in demanding high-demand environments

Field Reliability: Built to withstand moisture and vibration within the mixed air plenum

such as a grounded gas valve solenoid or damaged wiring

Siemens DDC 540-378 AutoZero Module 323080-701 Always cross-reference the original partThe Siemens DDC 540 378 AutoZero Module is a high precision calibration component engineered for Siemens building automation systems. This module serves as the primary solution for mitigating sensor signal drift within analog input loops, ensuring that pressure and airflow transducers maintain a stable baseline. By automating the zero point adjustment, the 540 378 eliminates the need for frequent manual recalibration in VAV systems and air handling