T-4506-204 Johnson Controls Thermostat

Overview

The Johnson Controls T-4506-204 is a dual-temperature, dual-dial pneumatic room thermostat designed to provide precise individual day and night, or two set-point temperature control in commercial and industrial HVAC systems. This high-volume output controller modulates pneumatic output signals in response to zone load changes, imposing minimal demand on mechanical heating and cooling apparatus. It operates as a direct-acting device designed for vertical wall mounting, facilitating automatic seasonal switchover based on system supply pressure changes without requiring a manual indexing switch.

Features

• Dual temperature and dual dial configuration provides independent day and night or two set-point environmental control.
• Automatic seasonal heating/cooling switchover occurs reliably at 17 psig without the need for an indexing switch.
• Direct-acting control action yields a straightforward, proportional pneumatic output response to space temperature changes.
• High-volume output flow capacity supports highly responsive pneumatic system performance.
• Single or dual bimetal sensing elements paired with pneumatic feedback ensure superior accuracy, stability, and resistance to shock or vibration.

Specifications

• Control Type: Pneumatic, Direct Acting (DIR)
• Temperature Settings: Dual Temperature (Day/Night or Heat/Cool)
• Mounting Orientation: Vertical
• Indexing Switch: None (Without Indexing Switch)
• Season Switchover Pressure: 17 psig
• Flow Capacity: 400 SCIM (107 mL/s)
• Air Consumption: 20 SCIM (5 mL/s)
• Supply Pressure Range: 13 to 25 psig (Nominal Day: 15 psig, Nominal Night: 20 psig)
• Dial Temperature Range: 55 degrees F to 85 degrees F (Fahrenheit scale dials)
• Air Connections: Two (Supply and Output) with 5/32-inch barb fittings
• Sensitivity: Adjustable from 0.75 to 4.0 psig/degree F (Factory set at approx. 2.5 psig/degree F)

Applications

• The T-4506-204 is ideally suited for commercial and institutional building HVAC pneumatic control networks where a single zone thermostat must manage both heating and cooling requirements or separate day/night setback schedules.
• Its high flow capacity and low air consumption make it an energy-efficient choice for facilities needing dependable, automatic climate adjustments across distinct operating cycles with minimal compressed air demand.