T-4756-206 Johnson Controls Thermostat

Overview

The Johnson Controls T-4756-206 is a pneumatic dual-temperature, dual-dial heating-cooling room thermostat designed to provide individual space temperature control in commercial and industrial HVAC applications. This high-volume output controller automatically switches between heating and cooling states through modifications in supply pressure, providing robust pneumatic signal capacity to efficiently drive downstream actuators and control systems.

Features

• Dual-temperature and dual-dial bimetal sensing elements enable heating and cooling functionality within a single unit.
• Provides automatic changeover between direct and reverse actions based on supply pressure adjustments.
• Offers a high-volume pneumatic output for reliable operation of downstream devices.
• Designed with adjustable sensitivities and separate individual set points on dual controllers.
• Vibration and shock-resistant construction ensures long-term dependability in occupied spaces.

Specifications

• Temperature Setting Range: 55 to 85°F
• Action Type: 15 psig Reverse Acting (Heating Control) / 20 psig Direct Acting (Cooling Control)
• Supply Pressure: Nominal 15 psig (13 to 18 psig) for the lower element; Nominal 20 psig (17 to 25 psig) for the upper element
• Switchover Pressure: Factory set at 17.5 psig (adjustable from 15 to 20 psig)
• Sensitivity: Adjustable from 0.75 to 4 psi/°F (Factory set at 2.5 psi/°F)
• Air Consumption: 20 scim
• Output Flow Capacity: 400 scim
• Air Connections: Barbed fittings for 5/32 in. O.D. polytubing
• Ambient Temperature Limits: -20 to 130°F
• Mounting Orientation: Vertical mounting

Applications

• Commercial building HVAC pneumatic control systems.
• Industrial facilities requiring dual heating and cooling thermostat management.
• Integration with fan coil units, variable air volume (VAV) systems, and air handling units.
• Retrofit and replacement of existing legacy pneumatic room thermostat installations.