Johnson Controls T-4100-1 Thermostat

The Johnson Controls T-4100-1 is a professional-grade single temperature pneumatic thermostat engineered for precise proportional control of industrial and commercial HVAC systems. This direct acting pneumatic thermostat features a low-volume output design, making it a reliable drop-in replacement for legacy pneumatic control systems. Operating within a dial range of 55 to 85?F, the T-4100-1 is optimized for vertical mount thermostat configurations and requires a supply pressure of 13 to 25 psig. For field calibration and performance tuning, the unit delivers 45 SCIM with a .007" restrictor or 25 SCIM with a .005" restrictor. This Johnson Controls pneumatic controller is built for technicians who demand stable setpoint maintenance in commercial HVAC maintenance environments without the complexity of modern digital overlays. Its rugged internal construction ensures compatibility with standard pneumatic HVAC valves and actuators across various building automation frameworks.

Product Features and Benefits

• Direct Acting Control: Ensures immediate increase in output pressure as the sensed temperature rises, ideal for cooling application logic.
• Precise Airflow Metrics: Factory-rated for low volume output to optimize pneumatic air consumption across the control loop.
• Standardized Pressure Range: Fully compatible with 13 to 25 psig supply lines common in vintage and modern industrial facilities.
• Flexible Restrictor Options: Supports multiple SCIM flows (25 or 45) to match specific HVAC system troubleshooting requirements and branch line lengths.
• Fahrenheit Scaled Interface: Features a clear 55 to 85?F dial for intuitive field adjustments by maintenance personnel.

Common Questions and Technical Support

How do I calibrate the T-4100-1 for specific branch line sensitivity?
Calibration is achieved by measuring the output pressure at the test port while adjusting the setpoint dial. Ensure your supply pressure remains stable between 13 and 25 psig to maintain the accuracy of the proportional band.

Can this unit replace a double temperature or reverse acting thermostat?
No, this is a direct acting single temperature thermostat. If your application requires a dual-setpoint (day/night) or reverse acting logic, you must verify the control sequence before installation.

Is a restrictor required for operation?
Yes, this low-volume output model requires a restrictor (typically .005" or .007") in the supply line to ensure proper pneumatic signal modulation to the terminal device.

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.