Siemens Building Technology 192-224 Thermostat

The Siemens 192-224 Powerstar room thermostat is a specialized pneumatic temperature control solution designed for large-scale building automation and commercial HVAC energy management. This dual setpoint thermostat features two-pipe, high-capacity air logic to provide precise day/night (D/N) control, allowing for efficient temperature setback during unoccupied hours. Operating as a direct acting (DA/DA) controller, it utilizes a sensitive bimetal element that modulates air pressure in response to thermal changes, ensuring stable operation for pneumatic valves and damper actuators. The unit transitions between setpoints by adjusting the supply pressure: 18 psi for day operation and 25 psi for night mode. This makes the Siemens 192-224 an essential component for contractors managing multi-zone facilities like schools and hospitals, where optimizing system efficiency via pressure-switched setbacks is a technical priority. Its Celsius-scaled adjustment range of 7°C to 30°C and compatibility with standard 5/32" OD plastic tubing facilitate a streamlined HVAC retrofit or new system integration.

• Dual Setpoint Efficiency: Enables separate temperature limits for occupied and unoccupied cycles via 18/25 psi supply air switches.
• Direct Acting Reliability: The DA/DA switching configuration ensures consistent proportional output for heating and cooling logic.
• Manual Override: Features an integrated override lever on the chassis, allowing occupants to temporarily return to day mode without resetting the entire zone.
• High Air Capacity: Large-volume air relay provides faster response times and supports multiple downstream actuators on a single branch.
• Ease of Calibration: Includes a factory-accessible test port for measuring control pressure without removing the cover, reducing diagnostic time for field technicians.

How do I switch the Siemens 192-224 between day and night modes?
Switching is handled pneumatically. Changing the supply air pressure from 18 psi to 25 psi automatically toggles the internal relay to the night setpoint.

Is this thermostat compatible with 3-pipe pneumatic systems?
No, this specific model is a 2-pipe pneumatic thermostat. Contractors needing a 3-pipe configuration should look for localized high-air-capacity variants specific to those architectures.

Can I calibrate the sensitivity in the field?
Yes, the sensitivity is field-adjustable from 1 to 4 psi/°F (12 to 50 kPa/°C) using the graduated scale on the internal chassis.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.