Johnson Controls A19ADB-38 Temperature Control

The Johnson Controls A19ADB-38 is a high-limit mechanical temperature control engineered for precision in demanding HVACR environments. This remote bulb temperature control operates across a wide 100 to 240 degree F setpoint range, providing a critical safety layer for hot water boilers and air heating systems. Utilizing an SPST (Single-Pole Single-Throw) switch configuration, the unit is designed to open high, effectively cutting power to the circuit when the user-defined threshold is met. As a manual reset device, it ensures the system remains locked out until a technician can investigate the cause of the high-limit trip, preventing automatic cycling under fault conditions. The A19ADB-38 serves as the direct A19ADN-1 replacement, maintaining the same 6-foot capillary length and 3/8" x 4" sensing bulb for seamless field installation. Its screwdriver slot range adjuster and visible scale allow for accurate calibration while preventing accidental setpoint drift.

• Universal Voltage Compatibility: Rated for 24 to 277Vac, making it a versatile stock item for various commercial and industrial control circuits.
• Precise Remote Sensing: The 6' capillary length and large sensing bulb allow for flexible mounting while ensuring rapid response to temperature fluctuations.
• Enhanced System Safety: The Manual Reset feature prevents hazardous equipment restarts after a high-limit event, ensuring operator intervention.
• Reliable Switch Action: Dust-tight SPST contacts provide dependable open high logic for critical protection applications.
• Rugged Construction: Built with a NEMA 1 enclosure, this control is designed to withstand standard mechanical room conditions.

What is the maximum bulb temperature for the A19ADB-38?
The sensing element is designed to handle temporary over-temperature conditions up to 290?F (143?C) without affecting the calibration of the liquid-filled element.

Can I use this to replace a discontinued A19ADN-1?
Yes, the A19ADB-38 is the manufacturer-designated direct replacement for the A19ADN-1, featuring identical mechanical specifications and electrical ratings.

Does this unit support cooling applications?
No, this specific model is a high-limit "Open High" control intended for heating protection. For cooling or "Close High" applications, a different A19 series part number would be required.

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.