and PFG boilers (sizes 85–125)

protecting the 24V transformer and internal wiring

optimized for maximum heat transfer and protection against high-velocity flows up to 87

allowing for precise calibration of valve modulation to meet specific sequence requirements

Siemens Building Technology GMA221.1U Actuator 323080-701 and PFG boilers (sizes 85–125)The Siemens GMA221. 1U is a high performance OpenAir damper actuator engineered for reliable 2 position (on off) control in critical HVAC environments. Operating on a 120 VAC power supply, this direct coupled unit delivers a robust 62 lb in torque (7 Nm), making it the primary choice for managing return air, mixed air, and exhaust dampers in both constant and variable air volume (VAV) systems. The integrated spring return fail safe mechanism ensures