Johnson Controls T-4506-204 Pneumatic Thermostat

The Johnson Controls T-4506-204 is a professional-grade dual temperature pneumatic thermostat engineered for high-volume output in commercial HVACR environments. This direct acting controller is designed specifically for vertical mounting and facilitates individual day and night setpoints, or two distinct setpoint controls, without the need for an indexing switch. It manages transitions through a precise switchover at 17 psig, ensuring a seamless shift between the 15 psig nominal day and 20 psig nominal night supply pressures. With a 400 SCIM flow capacity and a focused 55 to 85 degree dial range, this unit maintains tight environmental tolerances while minimizing air consumption to just 20 SCIM. Contractors relying on the T-4000 series will find this model essential for day-night room thermostat applications where rapid response and proportional pneumatic output are required to modulate dampers or valves across a 13 to 25 psig supply pressure range.

• Dual-Element Control: Provides independent setpoints for day and night operation, optimizing energy efficiency in commercial facilities.
• High-Flow Pneumatic Output: Features a 400 SCIM flow capacity to ensure rapid response from controlled actuators and mechanical equipment.
• Precise Switchover Logic: Calibrated for a 17 psig switchover, allowing for automated transition between day and night cycles via supply pressure changes.
• Optimized Air Consumption: Efficient 20 SCIM consumption rating preserves compressor capacity in large-scale pneumatic footprints.
• Vertical Orientation: Specifically designed for vertical wall installation, fitting standard mounting brackets and decorative covers.

What is the difference between direct acting and reverse acting models?
The T-4506-204 is a direct acting thermostat, meaning an increase in sensed temperature results in a corresponding increase in branch line pressure. This is typically used for cooling applications or heating systems requiring this specific signal orientation.

Does this unit require a manual indexing switch for day/night transition?
No, this model is configured without an indexing switch. The transition is handled automatically by the central system increasing or decreasing the supply pressure between 15 and 20 psig.

Can I use a horizontal cover with this thermostat?
Standard T-4506-204 units are built for vertical mounting. While internally similar to horizontal models, the dial orientation and mounting holes are optimized for vertical installation to ensure accurate calibration and user access.

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.