QDY30A Submersible Liquid Level Sensor Instruction Manual

1. Introduction

The QDY30A Submersible Liquid Level Sensor is designed for accurate and reliable measurement of liquid levels in various applications such as water tanks, rivers, and deep wells. Its robust construction, featuring 304 & 316 stainless steel and a hermetically sealed housing, ensures suitability for most industrial liquids and an IP68 rating for water immersion. The sensor is simple to use; just place the probe at the bottom of the liquid container.

A ventilation tube integrated into the cable automatically compensates for changes in atmospheric pressure, ensuring consistent accuracy. The conductors are isolated from the external environment for long-term operational stability.

2. Safety Information

Please read and understand all instructions before installing or operating the device. Failure to follow these instructions may result in equipment damage, personal injury, or inaccurate readings.

• Electrical Safety: Ensure the power supply matches the sensor's requirements (DC9-30V, default DC24V). Disconnect power before making any electrical connections. All wiring should be performed by qualified personnel in accordance with local electrical codes.
• Installation Environment: Do not install the sensor in environments where it may be exposed to corrosive substances beyond its material compatibility (304 & 316 stainless steel).
• Cable Handling: Avoid sharp bends, kinks, or excessive pulling on the sensor cable, as this can damage internal wiring and the ventilation tube.
• Maintenance: Do not attempt to open or repair the sensor housing. Refer all servicing to qualified technicians.

3. Product Overview

The QDY30A sensor consists of a stainless steel probe, a durable cable with an integrated ventilation tube, and exposed wires for electrical connection. The probe features multiple openings at its tip for liquid entry and pressure sensing.

4. Specifications

5. Installation and Setup

The QDY30A sensor offers flexible installation methods, typically involving suspension via a cable hanger or fixed mounting with a flange.

5.1. Sensor Placement

Place the sensor probe at the bottom of the water tank, river, deep well, or any other liquid container where level measurement is required. Ensure the sensor tip is fully submerged and positioned to avoid direct contact with sediment or debris that could block the measurement openings.

Note: A 'blind area' of approximately 20mm exists at the very bottom of the sensor, meaning measurements are accurate above this point.

5.2. Cable Hanger Installation

For suspension, use a cable hanger to secure the sensor cable at the desired height. This method allows the sensor to hang freely in the liquid.

5.3. Flange Fixed Installation

Alternatively, the sensor can be fixed using a flange. This provides a more rigid installation, suitable for applications where the sensor needs to be held firmly in place.

5.4. Electrical Wiring

The sensor requires a DC9-30V power supply (default DC24V). Connect the sensor wires to your control system or display unit according to the specific output signal type you have chosen (4-20mA, 0-10V, RS485, etc.).

• For 4-20mA Output (2-wire): Typically, the red wire is connected to the positive power supply and the blue/black wire is connected to the negative power supply and the signal input of your receiver.
• For Voltage Output (0-5V, 0-10V, 1-5V) (3-wire): Typically, red is positive power, blue/black is negative power (ground), and a third wire (e.g., yellow or white) is the signal output.
• For RS485 Output (4-wire): Typically, red is positive power, blue/black is negative power (ground), and two additional wires (e.g., green and white) are for RS485 A and B data lines.

Always consult the specific wiring diagram provided with your sensor model for precise connections, as wire colors and functions can vary.

6. Operation

Once properly installed and wired, the QDY30A sensor will continuously measure the liquid level. The output signal (e.g., 4-20mA, 0-10V, RS485) will correspond to the measured liquid level within the specified measuring range. Connect the sensor's output to a compatible display, PLC, or data acquisition system to monitor the liquid level.

• Calibration: The sensor is factory-calibrated. If recalibration is needed, refer to the specific instructions for your chosen output signal and control system.
• Monitoring: Regularly monitor the output signal to ensure accurate readings and detect any anomalies.

7. Maintenance

The QDY30A sensor is designed for long-term, low-maintenance operation due to its robust construction and hermetically sealed components.

• Regular Inspection: Periodically inspect the sensor probe and cable for any signs of damage, corrosion, or accumulation of debris.
• Cleaning: If debris or buildup is observed on the sensor tip, carefully remove the sensor from the liquid and clean the measurement openings with a soft brush or cloth. Avoid using abrasive materials or harsh chemicals that could damage the stainless steel housing.
• Cable Integrity: Ensure the cable remains free from physical stress, cuts, or damage. The internal ventilation tube is crucial for atmospheric pressure compensation; any damage to the cable can compromise this function.
• Ventilation Tube: The ventilation tube in the cable automatically compensates for atmospheric pressure changes. Ensure the end of the ventilation tube (usually near the wiring termination) is not blocked or submerged in liquid.

8. Troubleshooting

If you encounter issues with your QDY30A sensor, consider the following common problems and solutions:

• No Output/Incorrect Reading:
  • Check Power Supply: Verify that the sensor is receiving the correct DC9-30V power supply (default DC24V).
  • Check Wiring: Ensure all electrical connections are secure and correctly wired according to the sensor's output type.
  • Sensor Submersion: Confirm the sensor probe is adequately submerged in the liquid and not obstructed.
  • Debris: Inspect the sensor tip for any blockages from sediment or debris. Clean if necessary.
  • Ventilation Tube: Ensure the ventilation tube is not blocked or filled with moisture.
• Unstable Readings:
  • Environmental Factors: Rapid changes in liquid temperature or density can affect readings.
  • Electrical Interference: Ensure the sensor cable is routed away from strong electromagnetic fields.
  • Sensor Movement: Verify the sensor is stable and not moving excessively in the liquid.
• Sensor Not Responding:
  • Power Cycle: Disconnect and reconnect the power supply to reset the sensor.
  • Cable Damage: Inspect the entire length of the cable for any visible damage.

If the problem persists after attempting these solutions, please contact technical support.

9. User Tips

• For optimal accuracy, ensure the sensor's measuring range is appropriately matched to the maximum expected liquid level.
• When installing, consider using a protective cage or barrier around the sensor in environments with high flow or potential for physical impact to prevent damage.
• If using the RS485 output, ensure proper termination resistors are used in the communication network for reliable data transmission.
• Periodically verify the accuracy of the sensor readings against a known reference if critical measurements are required.

10. Warranty and Support

For warranty information, technical assistance, or to report any issues with your QDY30A Submersible Liquid Level Sensor, please contact QD Sensor Store customer support directly. Ensure you have your product model number and purchase details available when contacting support.