TEAO Construction: Totally Enclosed Air Over design prevents dust and moisture ingress

Durable Construction: Features robust terminals and high-grade insulation to prevent tracking and electrical shorting in humid environments

which significantly reduces operational noise and mechanical vibration

When replacing a Fasco D653

Siemens DDC 540-378 AutoZero Module 323080-701 TEAO Construction: Totally Enclosed AirThe 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