1. Product Overview
The Johnson Controls A19 Series Thermostat (Model A19AAT-2C) is a robust and compact temperature control device specifically engineered for temporary cooling installations. It features a Single-Pole, Single-Throw (SPST) switch that opens on a temperature drop, making it ideal for applications requiring precise temperature management outside the range of standard on-board thermostats.
Key Features:
- Single-stage cooling controls with SPST switches that open on temperature drop.
- Designed to override on-board refrigerator thermostats for accurate temperature control.
- Adjustable 20 to 80°F (-7 to 27°C) set point range with a fixed differential.
- Enclosed in a rugged steel NEMA 1 enclosure for durability.
- Includes a 6-foot extension cord with a piggyback style plug.
- Equipped with a remote sensing bulb and a 6 ft (1.8 m) capillary tube.
Image: The Johnson Controls A19AAT-2C Penn Series A19 Thermostat, showing its black housing, temperature adjustment dial, power cord with piggyback plug, and the coiled copper remote sensing bulb with its capillary tube.
2. Package Contents
Upon opening the package, verify that all components are present:
- Johnson Controls A19AAT-2C Thermostat Control Unit
- 6-foot Extension Cord with Piggyback Style Plug
- Remote Sensing Bulb with 6 ft (1.8 m) Capillary Tube
3. Setup Instructions
3.1. Location Selection
Choose a location for the thermostat control unit that is easily accessible and where the ambient temperature does not interfere with the sensing bulb's operation. Ensure the location is dry and protected from direct sunlight or extreme temperatures.
3.2. Sensing Bulb Placement
The remote sensing bulb is critical for accurate temperature measurement. Place the bulb in the area where temperature control is desired (e.g., inside a refrigerator or cooling chamber). Ensure the bulb is not in direct contact with cooling coils or heat sources, which could lead to inaccurate readings. The 6 ft (1.8 m) capillary tube allows for flexible placement.
3.3. Electrical Connection
The thermostat comes with a 6-foot extension cord and a piggyback style plug. Plug the thermostat's cord into a standard 120V AC outlet. Then, plug the appliance you wish to control (e.g., a portable cooling unit or refrigerator) into the piggyback receptacle on the thermostat's plug.
Warning: Ensure the appliance's power requirements do not exceed the thermostat's electrical ratings. Consult the appliance's manual for its power consumption.
4. Operating Instructions
4.1. Setting the Temperature
The A19AAT-2C thermostat features an adjustable dial for setting the desired temperature. The range is from 20°F to 80°F (-7°C to 27°C). Rotate the dial to the desired set point. The thermostat will activate the connected cooling appliance when the temperature rises above the set point and deactivate it when the temperature drops below the set point, maintaining the desired range.
4.2. Switch Action
This thermostat utilizes a Single-Pole, Single-Throw (SPST) switch that opens on temperature drop. This means that when the temperature in the sensed area falls below the set point, the electrical circuit to the connected appliance is interrupted, turning off the cooling unit. When the temperature rises above the set point, the circuit closes, and the cooling unit turns on.
5. Maintenance
5.1. Cleaning
Periodically wipe the exterior of the thermostat control unit with a soft, dry cloth to remove dust and debris. Do not use abrasive cleaners or immerse the unit in water.
5.2. Inspection
Regularly inspect the power cord, plug, and capillary tube for any signs of damage, such as fraying, cuts, or kinks. Ensure the sensing bulb remains securely in its intended location. If any damage is observed, discontinue use and contact a qualified technician for repair or replacement.
6. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Appliance not turning on/off | Incorrect temperature setting; Power issue; Damaged sensing bulb/capillary tube. | Verify set point; Check power outlet and connections; Inspect sensing bulb for damage. |
| Inaccurate temperature readings | Improper sensing bulb placement; External heat/cold interference. | Relocate sensing bulb away from direct heat/cold sources; Ensure bulb is fully exposed to the controlled environment. |
| Thermostat not responding | Unit malfunction. | Contact Johnson Controls customer support for assistance. |
7. Specifications
| Feature | Detail |
|---|---|
| Model Number | A19AAT-2C |
| Brand | Johnson Controls |
| Temperature Control Type | Cooling |
| Set Point Range | 20 to 80°F (-7 to 27°C) |
| Differential | 2 +/- 1.11°C (Fixed) |
| Switch Action | SPST Open Low (Opens on temperature drop) |
| Enclosure Type | Rugged Steel NEMA 1 |
| Power Cord Length | 6 feet |
| Sensing Bulb Capillary Tube Length | 6 ft (1.8 m) |
| Color | Black |
| Item Weight | 1.87 Pounds |
| Manufacturer | Johnson Controls Inc |
8. Warranty and Support
For information regarding the warranty of your Johnson Controls A19AAT-2C Thermostat, please refer to the documentation included with your purchase or visit the official Johnson Controls website. For technical support, troubleshooting assistance beyond this manual, or to inquire about replacement parts, please contact Johnson Controls customer service directly.
Johnson Controls Customer Service:
- Website: www.johnsoncontrols.com
- Phone: Refer to your regional Johnson Controls contact information.
