The Johnson Controls A19ABC-4 is a heavy-duty mechanical remote bulb temperature control designed for high-accuracy regulation in HVACR and industrial systems. Built with a liquid-filled sensing element, this SPDT temperature switch provides dependable single-stage control for both heating and cooling applications. It features a broad setpoint range of 50?F to 130?F and an adjustable differential of 3.5?F to 14?F, allowing technicians to fine-tune cycles and reduce equipment short-cycling. The 8-foot capillary tube and 3/8" x 5" sensing bulb offer significant installation flexibility, making it an ideal choice for walk-in coolers, ventilation systems, and tank heating. Compatible with voltages ranging from 24 to 277 VAC, this unit includes an automatic reset and a rugged NEMA 1 enclosure, ensuring long-term stability and precise thermal management in demanding environments without the need for complex electronics. Key Benefits for Contractors: Versatile Application: Operates as a universal HVAC temperature control for both open-high and open-low wiring configurations. Precision Tuning: Features an adjustable differential to maintain tight tolerances and optimize system efficiency. Flexible Mounting: Equipped with an 8-foot copper capillary to sense temperatures in hard-to-reach locations or remote ducts. Wide Voltage Compatibility: Handles 24V, 120V, 208V, 240V, and 277V, making it a "truck-stock" staple for various job sites. Industrial Durability: The mechanical remote bulb thermostat design uses no power to operate the internal sensing element, ensuring reliability. Common Questions: Can the A19ABC-4 be used for both heating and cooling? Yes. Thanks to the SPDT (Single-Pole, Double-Throw) switch action, you can wire it to break on temperature rise (for heating) or make on temperature rise (for cooling). What does the adjustable differential do? The differential determines the temperature change required to toggle the switch back to its original state. For instance, if set to 50?F with a 5?F differential, the unit cycles between 50?F and 55?F, preventing rapid cycling. Does this unit require a separate power supply to function? No. As a mechanical temperature control, the sensing element relies on liquid expansion to trip the switch, though the load it controls must stay within the 24?277 VAC rating. 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.
