Johnson Controls A19BUC-2 Control

The Johnson Controls A19BUC-2 is a heavy-duty explosion proof temperature control engineered for hazardous environments requiring precision and durability. Rated for Class I, Group D (NEMA 7) and Class II, Groups E, F, and G (NEMA 9), this mechanical thermostat ensures reliable operation where flammable vapors or combustible dusts are present. It features a single-pole, double-throw (SPDT) switch action with an automatic reset, supporting a wide voltage range from 24Vac to 277Vac. The 20 to 80 degree F setpoint range and 3.5 degree F fixed differential provide stable cycling for critical HVACR processes. This unit utilizes a coiled capillary and sensing bulb for rapid thermal response, making it an ideal drop-in solution for the Johnson Controls 2A20-2 replacement. The external knob adjuster allows for field calibration without breaching the explosion-proof housing, maintaining system integrity while simplifying setpoint adjustments for contractors.

• Explosion Proof Enclosure: UL listed for NEMA 7 and NEMA 9 hazardous locations, ensuring safe operation in volatile atmospheres.
• Fast Thermal Response: The coiled remote bulb design increases surface area for improved accuracy in air temperature sensing.
• Versatile Electrical Rating: SPDT contacts manageable across high-voltage HVAC systems and low-voltage control circuits.
• Rugged Mechanical Design: Built to withstand industrial vibration and environmental stress common in oil, gas, and chemical processing.

Is the A19BUC-2 compatible with cooling and heating applications?
Yes, the SPDT switch logic allows you to wire for either "open on rise" (heating) or "close on rise" (cooling) depending on your terminal connections.

Can this control be used for grain elevator applications?
Yes, its Class II, Group E, F, and G rating specifically covers environments with combustible metal, carbon, or agricultural dust.

How do I change the setpoint on an explosion-proof unit?
This model includes an external knob range adjuster, allowing you to change temperature settings manually without opening the sealed electrical housing.

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.