Johnson Controls A19BAC-1 Temperature Control

The Johnson Controls A19BAC-1 is a professional-grade mechanical temperature control designed for precise ambient space sensing in HVACR applications. This SPDT thermostat features a 30 to 110 degree F setpoint range and a 3.5 degree F fixed differential, ensuring tight cycle management and equipment protection. Specifically engineered for reliability, the unit utilizes a 1 3/8" x 2 1/4" coiled bulb and capillary sensor that provides rapid response to air temperature fluctuations. Voltage versatility is a core strength, as the A19BAC-1 supports 24 to 277Vac operations, making it compatible with various commercial and industrial control circuits. With its automatic reset functionality and convertible range adjuster, this space temperature control is built for "set and forget" performance in demanding environments. This model serves as the direct replacement for A19BAA-5 and 2A37-1, allowing for seamless field upgrades without extensive rewiring or bracket modifications.

Key Performance Benefits

• Universal Voltage Compatibility: Operates across a wide 24Vac to 277Vac range for maximum field application flexibility.
• Precise Ambient Sensing: Large coiled bulb design increases surface area for highly accurate space temperature sensing.
• Rugged Mechanical Build: Features a durable NEMA 1 enclosure and high-quality SPDT switch contacts for long-term switching reliability.
• Convertible Adjustment: Equipped with a convertible range adjuster for internal or external setpoint selection depending on security needs.
• Legacy Compatibility: Engineered as a drop-in replacement for older Johnson Controls A19 series models, reducing downtime during service calls.

Common Installation Questions

How do I wire the A19BAC-1 for heating or cooling?
As an SPDT controller, use the Red and Blue terminals to open the circuit on temperature rise (heating) or the Red and Yellow terminals to close the circuit on temperature rise (cooling/ventilation).

Can this control be mounted in any orientation?
Yes, the mechanical bellows and coiled bulb capillary allow for versatile mounting, though internal components should be protected from direct moisture or heavy vibration.

Is the 3.5 degree F differential adjustable?
No, the A19BAC-1 features a fixed differential of 3.5 degrees Fahrenheit, which provides consistent cycling and prevents short-cycling of compressors or fans.

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.