Siemens Building Technology GCA221.1U Actuator 320819-301 While this is the OEM

While this is the OEM blower assembly

this American-made sheave is built for durability and consistent operation in demanding environments like fans and pumps

it requires a start capacitor to effectively kick over under load

Automatic Reset Logic: Features a 20°F differential for reliable HVAC system reset without manual intervention

By reducing boiler short-cycling and maintaining optimal operating temperatures

Siemens Building Technology GCA221.1U Actuator 320819-301 While this is the OEMThe Siemens GCA221. 1U is a high torque spring return rotary actuator engineered for reliable control of building automation dampers and valves. Operating on 120 VAC, this Open Closed (on off) actuator delivers 142 lb in (16 Nm) of torque, making it a standard choice for large air handlers and systems requiring fail safe positioning. Designed for mechanical spring return during power loss, it ensures the controlled component returns to its safety