Johnson Controls A19AAA-40 Temperature Control

The Johnson Controls A19AAA-40 is a heavy-duty, single-stage remote bulb thermostat designed for precision temperature regulation in demanding HVACR environments. Engineered with a liquid-filled sensing element, this control provides consistent "repeat" accuracy that remains unaffected by barometric pressure or cross-ambient temperature fluctuations. This specific model features a temperature range of 20?F to 80?F (?5?C to 28?C), making it an industry standard for walk-in coolers, display cases, and beverage cooling systems requiring strict thermal management. The 6-foot copper capillary offers versatile mounting options, while the NEMA 1 enclosure protects the snap-acting SPDT switches from dust and debris. Whether you are performing a thermostat replacement or a new installation, the A19AAA-40 ensures reliable cycling with a fixed 5?F (2.8?C) differential, preventing short-cycling and maintaining system efficiency in commercial refrigeration applications.

• Universal Application: Ideal for refrigeration temperature control in frozen food cases, milk coolers, and water chillers.
• High-Accuracy Sensing: The 6-foot capillary and liquid-filled bulb ensure the Johnson Controls A19AAA-40 reacts quickly to thermal changes.
• Contractor-Grade Durability: Features a rugged NEMA 1 enclosure and dust-protected, snap-acting SPDT contacts for long-term field reliability.
• Ambient Compensation: Maintains setpoint integrity even when the control head is subjected to varying ambient temperatures.

How do I wire the SPDT terminals for cooling applications?
For cooling (open on temperature drop), wire to the Red (Common) and Yellow terminals. For heating (open on temperature rise), use the Red and Blue terminals.

Can the A19AAA-40 be used in a walk-in freezer?
This model is rated for 20°F to 80°F. For freezer applications requiring temperatures below 20°F, we recommend the A19ABA series or specialized low-temp controls.

Does this unit include a bulb well?
The A19AAA-40 is a remote bulb model supplied with a mounting clip. If an immersion application is required, a WEL14A-602R bulb well must be ordered separately.

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.