Johnson Controls A28AA-36 Temperature Control

The Johnson Controls A28AA-36 is a heavy-duty two-stage temperature control engineered for precision in HVACR applications requiring staged heating or cooling. This A28 Series manual reset thermostat features two SPDT switch actions, allowing for independent circuit control over a wide voltage range of 120/208/240/277 Vac. Built with a 40/90 degree setpoint range, the unit maintains a fixed 3-degree differential for each stage, with an adjustable 2-7 degree differential between stages to prevent short-cycling. The 3/8" x 5 3/4" sensing bulb and 6-foot capillary length provide flexible installation options for remote sensing. Utilizing a knob range adjuster for field calibration, this control is a direct drop-in replacement for any A28AA-36C model. Its rugged construction ensures reliable performance in demanding environments where precise staged temperature control is critical for equipment longevity and thermal stability.

• Dual Stage Control: Independent SPDT switches allow for sequenced operation of multiple heating or cooling loads.
• Industrial Compatibility: Multi-tap voltage support (120V to 277V) ensures fitment across various commercial electrical configurations.
• Adjustable Interstage Differential: Fine-tune the 2-7 degree gap between stages to optimize system efficiency and reduce wear.
• Remote Sensing Capability: The 6-foot capillary allows for precise temperature monitoring away from the control body.

Common Questions

What is the difference between the A28AA-36 and the A28AA-36C?
The A28AA-36 is identical to the A28AA-36C model; the "C" suffix typically denotes commercial packaging, but the technical specifications and form factor are the same.

Can this control be used for both heating and cooling?
Yes, because it utilizes dual SPDT switches, it can be wired to open or close on temperature rise, making it suitable for heating, cooling, or ventilation staging.

How do I adjust the spacing between the two stages?
While each individual stage has a fixed differential of 3 degrees, the internal adjustment allows you to set the gap between the activation of stage 1 and stage 2 from 2 to 7 degrees.

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.