The Johnson Controls A19ADB-29 is a heavy-duty single-stage utility thermostat engineered for high-temperature limit control in commercial and industrial HVACR systems. This remote bulb temperature control operates within a wide 90°F to 325°F (32°C to 163°C) range, making it a reliable choice for hot water boilers, deep fat fryers, and industrial heating equipment. The unit includes a 10-foot liquid-filled copper capillary and a 1/4" x 5" sensing bulb for rapid response to thermal fluctuations. Designed for safety and precision, the A19ADB-29 features an Open High switch action with a manual reset lockout. This ensures that once the high-limit setpoint is reached, the SPST (Single-Pole Single-Throw) contacts lock open and require a physical technician intervention to resume operation. The enclosed setpoint adjustment and internal scale plate prevent unauthorized tampering while maintaining consistent calibration. This model is electrically rated for 120/208/240 VAC, capable of switching line voltages directly without the need for additional relays in most standard applications. For those cross-referencing parts, the A19ADB-29 is identical to the A19ADB-29C. Key Benefits for Contractors High-Temperature Protection: The manual reset lockout prevents automatic recycling, ensuring equipment is inspected after a high-limit event. Flexible Installation: A 10-foot remote bulb capillary allows for the sensing element to be placed deep within equipment while the control box remains accessible. Universal Voltage Compatibility: Supports 120V, 208V, and 240V AC pilot duty and motor loads, streamlining truck stock requirements. Rugged NEMA 1 Enclosure: Protects the snap-acting contacts and internal mechanisms from dust and debris in mechanical rooms. Repeat Accuracy: The liquid-filled sensing element provides reliable performance regardless of ambient temperature variations around the control case. Common Questions & Installation Tips Does this unit require a power supply? No, the A19 series uses a mechanical sensing element and does not require external power for operation; it simply acts as a switch for the connected load. Can this be used for cooling applications? No, this model is specifically an Open High (cut out on temperature rise) control intended for heating limits. For cooling or refrigeration, look for an "Open Low" or SPDT A19 model. What is the maximum bulb temperature? To prevent damage to the sensing element, ensure the bulb does not exceed the manufacturer's maximum ambient rating, typically 350°F for this high-range series. This item is not eligible for free shipping. 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.
