Johnson Controls T-3100-3 Thermostat

The Johnson Controls T-3100-3 is a precision-engineered pneumatic thermostat designed for non-relay type proportional control in commercial HVAC systems. This reverse acting controller utilizes a liquid-filled sensing element and a 42-inch capillary tube, making it ideal for remote bulb thermostat applications where internal cabinet sensing is required. Operating with a 60 to 150 degree Fahrenheit range and a 25 psig maximum supply pressure, this unit is built for HVAC zone control stability. The inclusion of a barbed restrictor tee for 1/4" OD polytubing and a 1/8" FPT slave air connection ensures seamless integration into existing pneumatic control systems. This model provides dependable terminal equipment control without the complexities of electronic conversion, maintaining the throttling range necessary for accurate pneumatic temperature control. For contractors performing retrofits or maintenance, this unit ships complete with its protective cover and mounting bracket for immediate field installation.

• Remote Sensing Capability: The 42-inch capillary allows for flexible bulb placement away from the controller body.
• System Compatibility: Designed specifically for non-relay pneumatic circuits utilizing a restricted branch line.
• Durable Construction: Heavy-duty components provide long-term setpoint stability in high-demand environments.
• Installation Ready: Includes the barbed restrictor tee and mounting hardware to streamline the replacement process.

Is the T-3100-3 compatible with direct acting systems?
No, this specific model is reverse acting, meaning the output pressure decreases as the temperature rises. Ensure your application requires this control logic before installation.

What is the purpose of the 1/8" FPT slave air connection?
This port is designed for connecting a slave thermostat or an auxiliary air-operated device to the same control branch.

How do I handle the 1/4" OD tubing connection?
The unit comes with a barbed restrictor tee specifically sized for 1/4" OD polytubing, ensuring a secure, leak-free pneumatic seal.

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.