Johnson Controls A19AAD-5 Temperature Control

The Johnson Controls A19AAD-5 is a professional-grade, mechanical remote bulb temperature control designed specifically for demanding agricultural and commercial refrigeration applications, such as bulk milk cooler systems. This single-stage temperature control features a SPST (Single Pole, Single Throw) switch configuration with Open Low action, meaning it breaks the circuit on a temperature drop to the setpoint. It operates reliably across a wide voltage range from 24 to 277Vac, providing the versatility needed for various field installations. Note that the A19AAD-5 is identical to A19AAD-5C, ensuring seamless replacement in existing equipment.

Engineering-wise, this unit utilizes a liquid-filled sensing element and a 6-foot copper capillary length to deliver precise thermal response. The 3/8" x 2 5/8" sensing bulb is optimized for liquid immersion or air temp monitoring, maintaining a narrow 2.5 degree F fixed differential to prevent excessive short-cycling. Technicians can easily manage the 30 to 50 degree F setpoint range via a convenient screwdriver slot range adjuster, which prevents accidental tampering in the field. This mechanical thermostat is built for longevity in high-moisture environments, providing an automatic reset function that ensures continuous operation once the temperature rises above the differential.

• Specialized setpoint range (30-50?F) specifically calibrated for milk cooling applications and precise refrigeration control.
• High-voltage compatibility (up to 277Vac) allows for integration into 120V, 208V, or 240V circuits without additional transformers.
• Ambient compensation helps maintain accuracy regardless of the temperature fluctuations at the control head itself.
• Rugged mechanical design offers the reliability of automatic reset without the complexity of electronic controllers.
• Easy field adjustment via the screwdriver slot ensures the 2.5?F differential stays locked in for tight process control.

What is the difference between A19AAD-5 and A19AAD-5C?
These two part numbers are functionally and physically identical. The "C" suffix typically denotes bulk or commercial packaging from the manufacturer but does not change the technical specifications or performance of the hardware.

Can this control be used for heating applications?
No, this specific model features Open Low action (contacts open when the temperature drops), which is designed for cooling or low-temperature cutout. For heating, an 'Open High' action controller would typically be required.

Is the differential on the A19AAD-5 adjustable?
This model features a fixed 2.5 degree F differential. It is factory-set to ensure high-precision operation for sensitive applications like milk cooling, where consistent temperatures are vital for product safety.

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.