1. Introduction
The MS6818 Professional LCD Cable Tester is a versatile diagnostic tool designed for electricians, technicians, and DIY enthusiasts. It efficiently detects the laying paths of cables, electrical lines, and various pipelines buried within walls and underground. This device is also capable of identifying open and short-circuit faults, locating fuses and their associated circuits, and finding covered sockets and junction boxes. With its integrated AC/DC voltmeter function, it can measure voltages from 12V to 400V, making it an indispensable tool for various electrical and plumbing tasks.

2. Product Features
- Cable & Pipeline Tracing: Detects the laying paths of cables, electrical lines, water, and gas pipelines buried in walls and underground.
- Fault Detection: Identifies open and short-circuit faults in cables and electrical circuits.
- Fuse & Circuit Location: Pinpoints fuses and their corresponding circuits.
- Hidden Object Detection: Locates covered sockets and junction boxes.
- Floor Heating Line Faults: Finds open and short-circuit faults in electric heating lines under the floor.
- Integrated Voltmeter: Transmitter features a built-in AC and DC voltmeter function, measuring 12~400V (AC: 50~60Hz ±2.5%, DC: ±2.5%).
- Clear LCD Displays: Both transmitter and receiver have LCD screens displaying power levels, transmit codes, battery levels, measured voltage values, and high-voltage warnings.
- Self-Check Function: Transmitter includes a self-check feature for emission status.
- Adjustable Sensitivity: Receiver sensitivity can be adjusted automatically or manually.
- Automatic Frequency Sweep: Receiver has an automatic frequency sweep function.
- Mute Function: Both units offer a mute function.
- Automatic Shutdown: Receiver automatically powers off after 10 minutes of inactivity.
- Backlight & Flashlight: LCD backlight and flashlight functions for use in low-light conditions.
- Expandable: Supports additional transmitters for expanding capabilities or distinguishing multiple signals.
- Durable Design: Compact, durable, and easy-to-carry structure.
3. Package Contents
Please check the package carefully upon receipt to ensure all items are present and undamaged:
- 1 x Transmitter (batteries not included)
- 1 x Receiver (batteries not included)
- 2 x Test Lines (red and black)
- 1 x Storage Bag
- 1 x Ground Rod
- 1 x Instruction Manual

4. Safety Information
Always adhere to local safety regulations and guidelines when working with electrical systems. Failure to do so may result in injury or damage to the device.
- Ensure the device is in good working condition before use.
- Do not use the device in wet conditions or explosive environments.
- Always wear appropriate personal protective equipment (PPE), such as insulated gloves and safety glasses, when working with live circuits.
- Verify that the voltage being tested is within the specified range of the device (12-400V).
- Do not attempt to open or modify the device. Refer all servicing to qualified personnel.
- Keep the device away from children.
5. Setup
5.1 Battery Installation
The Transmitter requires one 9V (IEC 6LR61) battery, and the Receiver requires six 1.5V AAA (IEC LRO3) batteries. Batteries are not included.
- Locate the battery compartment on the back of both the Transmitter and Receiver units.
- Open the battery compartment cover.
- Insert the batteries, ensuring correct polarity (+/-).
- Close the battery compartment cover securely.
5.2 Connecting Test Leads
For most applications, connect the red and black test leads to the corresponding input jacks on the Transmitter. The other ends of the test leads will be connected to the circuit or cable you wish to trace.


6. Operating Instructions
6.1 General Cable Tracing
- Connect the Transmitter to the cable or circuit you want to trace. Ensure a good electrical connection. For non-energized cables, you may need to connect one lead to the cable and the other to a ground rod.
- Turn on both the Transmitter and Receiver.
- On the Transmitter, select the desired transmit power level and code using the 'LEVEL SEL' and 'CODE SEL' buttons. Press 'START/STOP' to begin transmission.
- On the Receiver, adjust the sensitivity ('LEVEL' buttons) as needed.
- Move the Receiver along the suspected path of the cable. The signal strength displayed on the LCD and the audible tone will increase as you get closer to the cable.
- Follow the strongest signal to accurately trace the cable's path.


6.2 Voltage Measurement (Transmitter)
The Transmitter can measure AC and DC voltages directly.
- Connect the test leads from the Transmitter to the voltage source.
- The Transmitter's LCD will automatically display the measured voltage value and indicate whether it is AC or DC. A high-voltage flash warning symbol will appear if applicable.
6.3 Fuse and Circuit Finding
- Connect the Transmitter to the circuit where the fuse is located.
- Use the Receiver to scan the fuse box. The strongest signal will indicate the correct fuse.


6.4 Using the Flashlight
Both the Transmitter and Receiver are equipped with a flashlight function. Press the dedicated flashlight button (often indicated by a light bulb icon) to activate it, useful for working in dark areas.
6.5 Video Demonstration
7. Maintenance
- Cleaning: Wipe the device with a dry, soft cloth. Do not use abrasive cleaners or solvents.
- Storage: Store the device in its storage bag in a cool, dry place when not in use. Remove batteries if storing for extended periods to prevent leakage.
- Battery Replacement: Replace batteries promptly when the low battery indicator appears on the LCD.
- Inspection: Periodically inspect test leads and connectors for any signs of wear or damage. Replace if necessary.
8. Troubleshooting
8.1 No Signal or Weak Signal
- Check Batteries: Ensure both the Transmitter and Receiver have sufficient battery power. Replace if low.
- Connection: Verify that the test leads are securely connected to the Transmitter and the circuit/cable.
- Transmitter Status: Check the Transmitter's LCD for its emission status and any error messages.
- Receiver Sensitivity: Adjust the Receiver's sensitivity level. Increase it for deeper or weaker signals.
- Interference: Strong electromagnetic fields from other devices can interfere with the signal. Try to minimize such interference.
- Distance: Ensure the Receiver is within the effective tracking range of the Transmitter.
8.2 Inaccurate Readings
- Calibration: While the device has an auto-sweep function, ensure you are following the operating instructions for your specific task.
- Environmental Factors: The tracking depth and accuracy can be affected by the medium (e.g., concrete, soil) and the presence of other metallic objects.
9. Specifications
9.1 Transmitter Specifications
| Parameter | Value |
|---|---|
| Output Signal | 125kHz |
| External Voltage Identification Range (DC) | 12-400V ±2.5% |
| External Voltage Identification Range (AC) | 12~400V (50~60Hz) ±2.5% |
| Temperature Measurement Accuracy | ±2.5℃ |
| Display | LCD, with function display and bar graph |
| External Voltage Dielectric Strength | Maximum 400VAC/DC |
| Overvoltage Category | CATIII300V |
| Pollution Degree | 2 |
| Power Supply | 1x9V, IEC 6LR61 (not included) |
| Power Consumption (Min/Max) | ~31mA / ~115mA |
| Fuse | F0.5A1000V, 6.3x32mm |
| Working Temperature | -10℃ to 50℃, 80% RH (non-condensing) |
| Storage Temperature | -20℃ to +60℃, 80% RH (non-condensing) |
| Altitude | Up to 2000m |
| Dimensions (H x W x D) | 190x89x42.5mm |
9.2 Receiver Specifications
| Parameter | Value |
|---|---|
| Tracking Depth | Depends on medium and specific application |
| Cable Positioning Mode (Single Pole) | Approx. 0 to 2m |
| Cable Positioning Mode (Double Pole) | Approx. 0 to 0.5m |
| Cable Positioning Mode (Single Loop) | Up to 2.5m |
| Grid Voltage Identification | Approx. 0 to 0.4m |
| Display | LCD, with function display and bar graph |
| Power Supply | 6x1.5V AAA, IEC LRO3 (not included) |
| Power Consumption (Min/Max) | ~32mA / ~89mA |
| Working Temperature | -10℃ to 50℃, 80% RH (non-condensing) |
| Storage Temperature | -20℃ to +60℃, 80% RH (non-condensing) |
| Altitude | Up to 2000m |
| Dimensions (H x W x D) | 24.5x78x38.5mm |
10. User Tips
- For optimal tracing results, ensure the circuit is de-energized if possible, or use the lowest possible signal level on the transmitter to avoid signal bleed to adjacent lines.
- When tracing deeply buried cables, try to maintain a consistent distance and angle with the receiver for more accurate readings.
- Always check the battery levels before starting a task to avoid interruptions.
11. Warranty and Support
For any questions or support needs regarding your MS6818 Cable Tester, please contact the seller. All messages will be replied to within 24 hours.