Johnson Controls A19DAC-12 Temperature Control

The Johnson Controls A19DAC-12 is a heavy-duty strap-on surface mounted temperature control designed for precise fluid temperature regulation in commercial and industrial piping systems. Engineered with a Single Pole Double Throw (SPDT) switch action, this mechanical thermostat allows for versatile control of heating, cooling, or ventilation equipment. It operates across a 120Vac to 240Vac voltage range and features a setpoint range of 100 to 240 degrees F. The 10-degree F fixed differential ensures consistent cycling, while the automatic reset functionality provides reliable, unattended operation after temperature fluctuations. This unit includes a concealed range adjustment to prevent unauthorized tampering in high-traffic mechanical rooms. Designed for easy installation, the strap-on configuration eliminates the need for draining the system or installing thermal wells, making the A19DAC-12 temperature control a preferred choice for rapid field replacements in hydronic heating systems and boiler applications.

Key Benefits for Contractors

• Strap-on surface mounting allows for quick installation directly onto piping without breaking the closed loop.
• SPDT switch logic provides flexibility to wire for open-on-rise or close-on-rise sequences.
• Concealed adjustment dial protects system parameters from accidental or unauthorized changes.
• Automatic reset ensures the system returns to standard operation immediately once the 10-degree differential is met.
• Wide voltage compatibility supports standard 120V and 240V industrial control circuits.

Common Questions

Is the A19DAC-12 suitable for high-limit or low-limit applications?
Yes, the SPDT switching allows it to function as either a high-limit or low-limit controller depending on which terminals are utilized during wiring.

Does this unit require a separate well for sensing fluid temperature?
No, this is a surface-mounted control that uses a sensing element designed to be strapped directly to the exterior of the pipe.

Can the differential be adjusted in the field?
The A19DAC-12 features a fixed 10-degree F differential, which is non-adjustable to maintain specific cycling intervals and prevent short-cycling.

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.