1. Introduction
The Heschen LJC12A3-5-Z/BY is a capacitive proximity sensor designed for non-contact detection in automated control systems. This sensor is capable of detecting various materials, including metals, plastics, glass, and liquids, without physical contact. Its robust design and reliable performance make it suitable for a wide range of industrial applications.
Figure 1: A close-up view of the Heschen LJC12A3-5-Z/BY capacitive proximity sensor body, showing its threaded metallic casing and product labeling.
2. Safety Information
Please read and understand all safety instructions before installing or operating this device. Failure to follow these instructions may result in electric shock, fire, or serious injury.
- Ensure power is disconnected before any installation or wiring procedures.
- This device operates on 10-30 VDC. Verify your power supply matches this requirement.
- Do not exceed the maximum output current of 200 mA.
- Protect the sensor from excessive mechanical stress, vibration, and extreme temperatures.
- Installation should be performed by qualified personnel in accordance with local electrical codes.
3. Package Contents
The package typically includes:
- 1 x Heschen LJC12A3-5-Z/BY Capacitive Proximity Sensor
- Mounting nuts and washers (pre-installed or included separately)
4. Setup and Installation
4.1 Mounting
The sensor features an M12 threaded body for easy panel mounting. A 12mm diameter hole is required for installation.
- Drill a 12mm diameter hole at the desired mounting location.
- Insert the sensor into the hole.
- Secure the sensor using the provided clamp nuts and buckle washer on both sides of the mounting panel. Ensure it is tightened securely but do not overtighten.
Figure 2: Heschen LJC12A3-5-Z/BY Capacitive Proximity Sensor with its attached cable. This image shows the full length of the sensor body and the three-wire cable.
Figure 3: Technical drawing illustrating the dimensions of the LJC12A3-5-Z/BY sensor, including its M12x1 thread, 60mm body length, and 120cm cable length. Also shown are graphs depicting the ratio of inducing different materials and the effect of object size on detection distance.
4.2 Wiring
The LJC12A3-5-Z/BY is a 3-wire PNP Normally Open (NO) sensor. Connect the wires as follows:
- Brown (BN): +10-30 VDC (Power Supply Positive)
- Blue (BU): 0 VDC (Power Supply Negative / Ground)
- Black (BK): Signal Output (Connect to load or control input)
When an object is detected, the black wire (signal output) will switch to the positive supply voltage (PNP output).
Figure 4: Detailed wiring diagram for the LJC12A3-5-Z/BY sensor, showing the connection points for Brown (BN), Black (BK), and Blue (BU) wires, along with the internal circuit representation.
5. Operation
Once properly installed and wired, the sensor is ready for operation. The nominal detection distance is 5mm.
5.1 Detection Principle
Capacitive proximity sensors detect changes in capacitance caused by the presence of an object within their electric field. This allows them to detect both conductive and non-conductive materials.
5.2 Sensitivity Adjustment
The sensor features an operating distance adjusting potentiometer at its rear. This allows fine-tuning of the detection sensitivity to suit different materials and application requirements. Turn the potentiometer clockwise to increase sensitivity and counter-clockwise to decrease it.
An operating indication light (LED) is present on the sensor to visually confirm detection. The LED illuminates when an object is detected within the set range.
Figure 5: Close-up view of the rear end of the sensor, highlighting the operating distance adjusting potentiometer and the operating indication light (LED).
6. Maintenance
The Heschen LJC12A3-5-Z/BY sensor is designed for low maintenance. Regular inspection and cleaning can help ensure optimal performance.
- Keep the sensor's detection surface clean and free from dust, dirt, or debris. Use a soft, dry cloth for cleaning.
- Periodically check wiring connections for tightness and signs of damage.
- Ensure the sensor is securely mounted and not subject to excessive vibration.
7. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Sensor not detecting objects. | Incorrect wiring, no power, sensitivity too low, object out of range, sensor malfunction. |
|
| Inconsistent or erratic detection. | Interference, sensitivity too high, unstable mounting, environmental factors. |
|
| Sensor LED is always ON/OFF. | Sensor stuck in detection/non-detection state, sensitivity issue, sensor malfunction. |
|
8. Specifications
| Feature | Specification |
|---|---|
| Model Number | LJC12A3-5-Z/BY |
| Detection Distance | 5 mm |
| Mounting Hole Diameter | 12 mm |
| Operating Voltage | 10-30 VDC |
| Output Current | 200 mA |
| Output Type | PNP Normally Open (NO) |
| Wiring Type | 3-wire |
| Cable Length | 120 cm |
| Material | Plastic, Metal |
| IP Rating | IP54 |
| Operating Mode | ON-OFF |
| Connector Type | Wired cables |
| Terminal | Through-hole |
| Control Method | Sensor |
| Number of Positions | 1 |
| Actuator Type | Without actuator |
| Package Dimensions | 9 x 7 x 1 cm |
| Product Weight | 20 grams |
9. Warranty and Support
Heschen products are manufactured to high-quality standards. For warranty information or technical support, please refer to the retailer's return policy or contact Heschen customer service through their official channels. Keep your purchase receipt for warranty claims.
