Johnson Controls T-4506-203 Thermostat

The Johnson Controls T-4506-203 is a professional-grade dual temperature pneumatic thermostat engineered for high-performance HVAC control systems requiring direct acting logic. Designed for horizontal mounting, this unit facilitates seamless day/night or heating/cooling transitions with a 17 psig switchover pressure. With a robust 400 SCIM flow capacity and a highly efficient 20 SCIM air consumption rate, the T-4506-203 ensures precise terminal equipment regulation while minimizing compressor load. This model operates within a 13 to 25 psig supply pressure range and features a 55 to 85 degree dial range, making it a reliable drop-in replacement for aging pneumatic control systems. Field technicians value this series for its proportional control accuracy and rugged construction, ensuring stable environmental control in commercial and industrial settings without the complexities of modern digital interfaces. Its direct acting output ensures that an increase in sensed temperature results in a corresponding increase in branch pressure.

• Optimized Airflow: High 400 SCIM flow capacity supports rapid response for larger actuators and terminal units.
• Efficient Operation: Low 20 SCIM air consumption reduces energy costs and demand on the pneumatic plant.
• Simplified Integration: Designed for horizontal installation without an indexing switch, streamlining the replacement process in existing pneumatic thermostat footprints.
• Dual Temperature Control: Enables automated setpoint shifts based on supply air pressure, perfect for energy-saving HVAC strategies.
• Precise Calibration: Features a sensitive 55 to 85°F range for exact comfort tuning in commercial HVAC systems.

Common Questions

How do I calibrate the T-4506-203 for accurate switchover?
Calibration involves adjusting the setpoint dial to match the ambient temperature while ensuring your supply pressure is correctly toggled between 13 and 25 psig to verify the 17 psig switchover point is functioning.

Can this thermostat replace an older T-4002 or T-4003 series?
Yes, provided the application requires direct acting logic and original mounting orientation was horizontal. Always verify the specific pneumatic control sequence before swapping units.

What causes high air consumption in these pneumatic units?
If air consumption exceeds the rated 20 SCIM, check for internal diaphragm leaks or fouled pilot filters, which are common HVAC troubleshooting points for older pneumatic loops.

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.