1. Introduction
This manual provides essential information for the proper installation, operation, and maintenance of the Heschen M18 Capacitive Proximity Sensor Switch, model LJC18A3-B-J/EZ. This non-shielded type sensor is designed for reliable non-contact detection of various dielectric materials.
2. Safety Information
- Electrical Safety: Always disconnect power to the circuit before installing, wiring, or performing maintenance on the sensor to prevent electric shock.
- Qualified Personnel: Installation and wiring should only be performed by qualified electrical personnel familiar with industrial control systems and safety standards.
- Voltage Compatibility: Ensure the supply voltage (90-250 VAC) matches the sensor's specifications. Incorrect voltage can damage the device.
- Environmental Conditions: Do not expose the sensor to conditions outside its specified operating temperature and humidity ranges.
- Secure Mounting: Ensure the sensor is securely mounted to prevent accidental dislodgement or damage.
3. Product Overview
The Heschen LJC18A3-B-J/EZ is an M18 cylindrical capacitive proximity sensor. It features a non-shielded design, allowing for a wider detection range compared to shielded types. The sensor provides a Normally Open (NO) output and operates on AC voltage.
Figure 1: Heschen M18 Capacitive Proximity Sensor Switch LJC18A3-B-J/EZ with connecting cable.
Key Components:
- Sensor Body: M18 threaded nickel-plated brass housing.
- Detection Surface: ABS material, responsible for sensing.
- Operating Distance Adjusting Potentiometer: Located at the rear of the sensor for fine-tuning detection sensitivity.
- Operating Indication Light: A red LED that illuminates when an object is detected.
- Power Wire: Two-wire cable for power connection.
Figure 2: Rear view of the sensor, highlighting the operating distance adjustment potentiometer and the operating indication light.
4. Specifications
| Parameter | Value |
|---|---|
| Model | LJC18A3-B-J/EZ |
| Mounting Hole Diameter | 18mm |
| Detecting Distance | 10mm ±10% |
| Set Distance | 0-8mm |
| Output Type | Normally Open (NO), Non-Shield Type |
| Current Output | 400mA |
| Working Voltage | 90-250 VAC |
| Supply Voltage Frequency | 50/60Hz |
| Consumption Current | Less than 1.7mA |
| Detection Object | Any dielectric material |
| Loop Protection | Surge absorption |
| Ambient Temperature | -30℃ to +65℃ (no freeze, no dew) |
| Ambient Humidity | 35-95% RH |
| Insulation Impedance | 50MΩ above (DC500 megameter) |
| Withstand Voltage | AC1000V 50/60Hz for 1 minute |
| Material (Shell) | Nickel plated brass |
| Material (Detection Surface) | ABS |
| Cable Length | 150cm (59 inches) |
Figure 3: Detailed dimensions of the sensor and graphs illustrating the ratio of inducing different materials and the effect of object size on detection distance.
5. Setup
5.1 Mounting
- Select a suitable location for the sensor, ensuring it is within the desired detection range of the target object and away from strong electromagnetic interference.
- Drill an 18mm diameter hole for mounting.
- Insert the sensor into the mounting hole.
- Secure the sensor using the provided clamp nut and buckle washer. Ensure it is firmly tightened to prevent movement.
5.2 Wiring
The LJC18A3-B-J/EZ is a 2-wire AC sensor. Refer to the wiring diagram below for correct connection.
Figure 4: Wiring diagram for the 2-wire AC Normally Open (NO) sensor. Connect the Brown (BN) wire and Blue (BU) wire to the 90-250VAC power supply.
- Connect the Brown (BN) wire to one line of the 90-250VAC power supply.
- Connect the Blue (BU) wire to the other line of the 90-250VAC power supply.
- Ensure all connections are secure and insulated to prevent short circuits.
6. Operating
6.1 Detection Principle
This capacitive proximity sensor detects the presence of objects by sensing changes in capacitance. It can detect any dielectric material, including liquids, powders, and non-metallic solids, without physical contact. The detection distance is influenced by the dielectric constant of the material and the size of the object.
6.2 Adjusting Detection Distance
The detection distance can be adjusted using the potentiometer located at the rear of the sensor (refer to Figure 2). Rotate the potentiometer clockwise to increase sensitivity and detection distance, and counter-clockwise to decrease it. Adjust the potentiometer until the desired detection point is achieved for your specific application.
6.3 Indication
The red operating indication light on the sensor will illuminate when an object is detected within the set detection range, providing visual feedback on the sensor's status.
7. Maintenance
- Cleaning: Keep the detection surface clean and free from dust, dirt, or debris. Use a soft, dry cloth for cleaning. Avoid abrasive cleaners or solvents.
- Wiring Inspection: Periodically inspect the sensor's wiring for any signs of damage, fraying, or loose connections. Repair or replace damaged wiring immediately.
- Mounting Check: Ensure the sensor remains securely mounted. Vibrations or impacts can loosen the mounting over time.
- Environmental Monitoring: Verify that the operating environment remains within the specified temperature and humidity limits to ensure optimal performance and longevity.
8. Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| Sensor not detecting objects | No power to sensor Incorrect wiring Detection distance set too low Object material not detectable or too thin Sensor damaged | Check power supply and connections Verify wiring against diagram Adjust potentiometer to increase sensitivity Ensure object is within sensor capabilities Replace sensor if damaged |
| Erratic or unstable detection | Electromagnetic interference Unstable mounting Detection surface dirty Object moving too fast or inconsistently | Relocate sensor away from interference sources Ensure sensor is securely mounted Clean detection surface Adjust sensor position or object speed |
| Indication light not working | No power Light damaged Sensor not detecting | Check power and wiring Sensor may still function, but consider replacement if indication is critical Troubleshoot detection issues first |
9. Warranty and Support
For warranty information, technical support, or service inquiries regarding your Heschen M18 Capacitive Proximity Sensor Switch, please refer to the manufacturer's official website or contact Heschen customer support directly. Keep your purchase receipt for warranty claims.