Johnson Controls T-4506-202 Thermostat

The Johnson Controls T-4506-202 is a high-performance dual temperature pneumatic thermostat engineered for precise climate control in commercial and industrial HVAC systems. This direct acting bimetal controller features a vertical mounting configuration and an integrated manual indexing switch, allowing technicians to reset the day temperature locally during night setback cycles without disrupting the entire building automation loop. Designed for energy-efficient day/night operation, it utilizes a proportional output signal and high-volume 180 SCIM capacity to modulate terminal units, dampers, and valves with extreme accuracy.

The T-4506-202 operates with a dual supply pressure system: typically 15 psig for the day element and 20 psig for the night element, with a factory-calibrated switchover point at 17.5 psig. With a 55 to 85°F dial range and adjustable sensitivity from 0.75 to 4.0 psig/°F, this unit provides the versatility needed for demanding pneumatic control systems. Its rugged construction ensures vibration and shock resistance, making it a reliable standard for veteran contractors maintaining Johnson Controls T-4000 series legacy infrastructure.

• Dual Temperature Control: Independent day and night dials allow for effective setbacks, significantly reducing energy consumption in unoccupied spaces.
• Manual Indexing Switch: Provides contractors and occupants the ability to override night settings locally, restoring comfort without central system adjustments.
• High Volume Output: The 400 SCIM flow capacity ensures rapid response times for pneumatic actuators and controlled devices.
• Precise Calibration: Adjustable sensitivity allows for fine-tuning the proportional band to match specific mechanical room requirements.
• Durable Bimetal Sensing: Utilizes high-quality bimetal elements for long-term stability and resistance to environmental interference.

How do I adjust the switchover pressure on the T-4506-202?
The switchover point is factory-set at 17.5 psig. To adjust for non-standard supply pressures, use the switchover point adjusting screw located behind the cover, turning clockwise to increase the pressure threshold from the low side.

Can this thermostat be used in a reverse acting application?
No, the T-4506-202 is specifically a direct acting (DA) model. For reverse acting requirements, you would need to specify the T-4506-209 or a similar REV configuration.

What air connections are required for installation?
This model features two barbed air connections on the back, marked 'S' for the supply line and 'O' for the output signal, compatible with standard 5/32-inch O.D. polytubing.

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.