Introduction
This manual provides essential information for the safe and efficient installation, operation, and maintenance of the Johnson Controls A19ABC-24 Remote Bulb Temperature Control. This device is designed for precise temperature regulation within a range of 30°F to 100°F, featuring an automatic reset and Single-Pole Double-Throw (SPDT) switch action. Please read these instructions thoroughly before proceeding with installation or operation.
Safety Information
WARNING: Risk of Electric Shock.
- Disconnect all power to the circuit before installing or servicing this control. Failure to do so may result in serious injury or death.
- Installation and servicing must be performed by a qualified technician.
- Ensure all wiring complies with local and national electrical codes.
- Do not exceed the specified electrical ratings of the control.
This device is designed for specific applications. Do not use it for purposes other than those specified in this manual.
Setup and Installation
1. Mounting the Control
The A19ABC-24 control should be mounted in a location free from excessive vibration, moisture, and extreme temperatures outside its operating range. Secure the control housing using appropriate fasteners through the mounting holes provided.
Figure 1: Johnson Controls A19ABC-24 unit with cover open, revealing the temperature setting dial and electrical terminals.
2. Wiring Instructions
Refer to the wiring diagram on the product label and ensure all connections are secure and correct. This control features a Single-Pole Double-Throw (SPDT) switch. Use copper conductors only.
- RED: Common terminal.
- BLUE: Opens High (Normally Closed contact).
- YELLOW: Opens Low (Normally Open contact).
The control is rated for 120V and 240V applications. Verify the load requirements against the control's specifications before wiring.
Figure 2: Product label detailing wiring connections (RED, BLUE, YELLOW) and electrical load ratings.
3. Remote Bulb Placement
The remote bulb and capillary tube are critical for accurate temperature sensing. Position the bulb in the area where temperature is to be controlled. Ensure the capillary tube is not kinked, sharply bent, or damaged during installation. The 8-foot capillary allows for flexible placement.
Figure 3: The remote bulb and capillary tube, which senses the ambient temperature.
Operating Instructions
1. Setting the Temperature
To set the desired temperature, rotate the dial located on the control unit. The dial is marked in degrees Fahrenheit, ranging from 30°F to 100°F. Align the desired temperature with the indicator mark.
2. Differential Adjustment
The A19ABC-24 features a differential adjustment range of 3-12 degrees. The differential determines the temperature difference between the cut-in and cut-out points of the control. Adjust this setting as needed for your specific application to prevent rapid cycling of the controlled equipment.
- A smaller differential results in more frequent cycling but tighter temperature control.
- A larger differential results in less frequent cycling but wider temperature fluctuations.
3. Automatic Reset
This control is equipped with an automatic reset function. Once the temperature returns to the set point (considering the differential), the control will automatically switch its contacts back to their normal state without manual intervention.
Maintenance
The Johnson Controls A19ABC-24 is designed for reliable operation with minimal maintenance. However, periodic checks are recommended to ensure optimal performance and longevity.
- Cleaning: Keep the control unit and remote bulb free from dust, dirt, and debris. Use a soft, dry cloth for cleaning. Do not use abrasive cleaners or solvents.
- Inspection: Periodically inspect the capillary tube for any signs of damage, kinks, or leaks. Check electrical connections for tightness and corrosion.
- Calibration Check: If temperature accuracy is critical, periodically verify the control's set point against a calibrated thermometer.
WARNING: Disconnect power before performing any maintenance or inspection.
Troubleshooting
Before attempting any troubleshooting, ensure all power is disconnected from the unit.
| Problem | Possible Cause | Solution |
|---|---|---|
| Control not responding to temperature changes. |
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| Temperature not maintained accurately. |
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| Control cycles too frequently or infrequently. |
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Specifications
| Feature | Detail |
|---|---|
| Model Number | A19ABC-24 |
| Temperature Range | 30°F to 100°F (-1°C to 38°C) |
| Capillary Length | 8 feet |
| Reset Type | Automatic |
| Switch Type | SPDT (Single-Pole Double-Throw) |
| Differential Adjustment | 3°F to 12°F |
| Voltage Ratings | 24 VAC to 277 VAC, 120V, 240V |
| Power Source | Battery-powered (Note: Product specifications state "battery-powered" but also "Batteries Included? No" and "Batteries Required? No". This likely refers to the control circuit being able to operate on low voltage, not that it uses internal batteries for primary power. It's a mechanical control.) |
| Item Weight | 1 pound |
| Product Dimensions | 9 x 7 x 5 inches |
Warranty and Support
Johnson Controls products are manufactured to high-quality standards and are typically covered by a manufacturer's warranty. For specific warranty terms and conditions, please refer to the documentation provided with your purchase or visit the official Johnson Controls website.
For technical assistance, troubleshooting beyond this manual, or to inquire about replacement parts, please contact Johnson Controls customer support or your authorized distributor. When contacting support, please have your model number (A19ABC-24) and purchase information readily available.
Johnson Controls Official Website: www.johnsoncontrols.com
