Johnson Controls A70AA-16 Temperature Control

For veteran HVACR contractors, the Johnson Controls A70AA-16 Temperature Control is a standard-issue solution for heavy-duty refrigeration and heating limit applications. Designed as a single pole, single-throw (SPST) device, this controller is engineered to open low, breaking the circuit on a temperature drop to prevent coil freeze-up or maintain specific thermal boundaries. Operating on 120-240 Vac, it provides high-capacity switching for refrigeration compressors and ventilation fans without the immediate need for a contactor in many line-voltage setups.

This model features a calibrated 15/55 degree temperature range with a factory-set 5 degree fixed differential, ensuring consistent cycling and preventing short-cycling in critical environments. The 6' capillary length provides ample reach for remote sensing, while the automatic reset functionality ensures the system resumes operation as soon as the sensed temperature rises above the cut-in point. Built with a rugged 1/2" conduit opening for secure field wiring, the A70AA-16 is a reliable choice for freeze protection and air stratification monitoring in commercial air handling units.

Key Benefits for Technicians:

• Broad Compatibility: Rated for 120-240 Vac, making it a versatile choice for a wide variety of commercial refrigeration and heating service calls.
• Precision Freeze Protection: The Open Low action is purpose-built to act as a low-limit cutout, protecting coils from icing and subsequent system damage.
• Rapid Installation: Features a standard 1/2" conduit opening and a 6-foot lead, allowing for flexible mounting and straightforward integration into existing control circuits.
• Reliable Snap-Action Contacts: Designed for long-cycle life, the SPST switch maintains high contact force to ensure a clean break and minimize arcing.

Common Questions:

Can the differential be adjusted on the A70AA-16?
No, this specific model is a fixed differential temperature control set at 5°F. For applications requiring an adjustable differential, you should look toward the A19 series or other A70 models with adjustable screws.

Is this control suitable for pilot duty applications?
Yes, the Johnson Controls A70 series is rated for both line voltage loads and pilot duty, providing flexibility whether you are switching a motor directly or signaling a larger motor starter.

What is the purpose of the 6' capillary?
The capillary length allows for remote sensing, meaning you can mount the control box in an accessible area while the sensing bulb is placed directly in the air stream or on the coil surface where temperature monitoring is critical.

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.