WINAPEX 268B High Precision Clamp Meter User Manual

1. Overview

The WINAPEX 268B series of instruments is a highly reliable digital clamp meter designed for stable performance, powered by a lithium battery. It features a full-symbol, 17mm word height LCD display for clear readings. The adjustable screen brightness adapts to various environments, protects the user's eyes, and the screen display can rotate for easy reading. This model also includes voice broadcasting and comprehensive overload protection, ensuring user confidence.

This instrument measures the true effective value (True RMS) of DC voltage, AC voltage, DC current, AC current (clamp type), resistance, capacitance, frequency, Celsius, Fahrenheit, diode, and continuity. It also supports leakage detection in various scenarios. Built around a dual integral A/D conversion core, it offers superior performance and is recognized for its cost-effectiveness. It is an ideal tool for laboratories, factories, radio enthusiasts, and home use.

2. Safety Precautions

The design of this instrument complies with IEC1010 safety standards. Please read and follow these precautions carefully before use to ensure your safety and proper functioning of the clamp meter.

1. Always use the clamp meter according to the instructions provided. Failure to do so may compromise the safety protection features.
2. Adhere to national safety regulations. When working in environments with high voltage and exposed wires, always use personal protective equipment to prevent electric shock or arc discharge injuries.
3. Do not hold the current clamp meter in any position other than the protective shield.
4. Before each use, inspect the outer shell of the clamp for any cracks or defects. Pay special attention to the insulation around the clamp mouth.
5. When replacing the battery, ensure the clamp is removed from all live circuits and the leads are disconnected.
6. When changing the function or range, ensure the probe is removed from the test point first.
7. Voltages below 36V are considered safe. When measuring voltages above 36V DC or 25V AC, verify that the probe contacts are reliable, correctly connected, and have good insulation to prevent electric shock.
8. When measuring voltage, do not exceed the limit voltage of DC 1000V or AC 750V (effective value).

3. Common Symbols

Familiarize yourself with the symbols used on the instrument and in this manual:

4. Specifications

4.1 General Characteristics

• Display Method: LCD display
• Maximum Display: 5999 (3 5/6 digits), automatic polarity display
• Measurement Method: Double integral A/D conversion
• Updates Per Second: 2-3 times
• Over Range Display: "OL"
• Low Voltage Display: Battery symbol appears
• Working Environment: 0-40 °C, relative humidity <80%
• Power Supply: 3.7V lithium battery
• Battery Capacity: 750mAh
• Continuous Battery Life: 20 hours
• Dimensions (L x W x T): 165 × 68 × 26mm
• Weight: Approximately 280g (including battery)
• Executive Standards: GB/T13978

4.2 Technical Characteristics (Accuracy and Ranges)

Accuracy: ± (a% of reading + the lowest significant digit). Environmental temperature for calibration: (23 ± 5) °C, relative humidity <75%. Calibration warranty period: one year from factory date.

5. Setup

5.1 Package Contents

Before starting, ensure all items are present in the package:

• 1 x WINAPEX 268B Clamp Meter
• 1 x Pair of Test Leads (Red and Black)
• 1 x User Manual (this document)
• 1 x K-type Thermocouple (TP01)
• 1 x Type-C USB Charging Cable
• 1 x Storage Bag

5.2 Charging the Battery

The WINAPEX 268B comes with a built-in 3.7V lithium battery. To charge, connect the provided Type-C USB cable to the meter's charging port and a suitable USB power source. A full charge provides approximately 20 hours of continuous operation.

5.3 Operation Panel Overview

Familiarize yourself with the components of the clamp meter:

1. Clamp Head: Used for non-contact current measurement.
2. Model Sticker: Displays model information (268B).
3. LCD Display Screen: Shows measurement readings and functions.
4. Rotating Screen Button: Long press to rotate the screen display.
5. USB Charge Port: Type-C port for charging the internal battery.
6. Silicone Button Group: Includes various function and control buttons.
7. Indicator Light: Flashes red when active for beeping, EF (electric field), or LIVE (fire line) detection.
8. Test Positive End (VΩ): Connects to the red test probe.
9. Test Negative Terminal (COM): Connects to the black test probe.
10. Pliers Trigger: Opens and closes the clamp head.

6. Operating Instructions

6.1 Power On/Off and Function Selection

• Power On/Off: Press the red power button to turn the device on or off.
• Function Selection: Use the 'SELECT' button to cycle through different measurement functions (e.g., DCV, ACV, Resistance, Capacitance, Frequency, Diode, etc.).
• Screen Rotation: Long press the dedicated screen rotation button to rotate the display for easier viewing, especially when operating with both hands.
• Brightness Adjustment: Long press the brightness button for more than 2 seconds until a short beep sounds to enter brightness adjustment mode. Press again to cycle through 5 brightness levels. Long press again to exit.

6.2 DC Voltage Measurement

1. Insert the black test lead into the "COM" socket and the red test lead into the "V Ω" socket.
2. Ensure the probes reliably contact the test point. The screen will display the measured voltage value and polarity.
3. When measuring high voltage, avoid touching the high voltage circuit.
4. Do not exceed the input voltage of DC1000V or AC750V to prevent damage.

6.3 AC Voltage Measurement

1. Insert the black test lead into the "COM" socket and the red test lead into the "V Ω" socket.
2. Ensure the probes reliably contact the test point. The screen will display the measured voltage value.
3. The measured voltage should not exceed AC750V. Remove the probe from the test point before turning off or changing the function.
4. When measuring high voltage, avoid touching the high voltage circuit.

6.4 DC Current Measurement (Clamp Type)

1. Before testing, close the clamp head and press the "ZERO" key to reset it. If it is not zero, press it multiple times until the reading is zero.
2. Record the reading after the test, and repeat the reset step for each measurement.
3. Minimum measurement current is 5mA, maximum is 60A. "OL" indicates over range. Overload protection is 60A.
4. Be careful when measuring high voltage electricity to avoid electric shock.

6.5 AC Current Measurement (Clamp Type)

1. All AC current ranges are automatic. When measuring large currents, the range is identified from small to large. Larger fixed current values may require longer measurement times.
2. If the display shows "OL", the measured value has exceeded the maximum current.
3. When measuring AC current, only one live wire (phase wire) can be clamped. Keep the wire in the center position of the clamp.
4. When measuring current, the two clamps should be tightly connected without gaps to avoid measurement errors.

6.6 Resistance Measurement

Warning: Input voltage is prohibited in this range. Do not input voltage in the resistance range, as it may damage the instrument.

1. Insert the black test lead into the "COM" socket and the red test lead into the "V Ω" socket.
2. Press the "SELECT" button to choose the resistance function.
3. For the 600 Ω range, first short-circuit the probes to measure lead resistance, then subtract this value from the actual measurement.
4. When measuring above 1M Ω, the reading may stabilize slowly. Wait for the displayed value to stabilize before reading.
5. If the resistance value exceeds 60M Ω, "OL" will be displayed.
6. When measuring online resistance, ensure the power supply of the tested circuit is off and all capacitors are fully discharged.

6.7 Diode and Continuity Test

Warning: Input voltage is prohibited in this range.

1. Insert the black test lead into the "COM" socket and the red test lead into the "V Ω" socket (note the red lead is positive).
2. Press the "SELECT" key to switch to the Diode/Continuity position.
3. For diode test, connect the red probe to the positive pole of the diode and the black probe to the negative pole. The reading is the forward voltage drop in "V".
4. For continuity test, connect the probes to two points of the circuit. If the built-in buzzer sounds, the resistance between the points is less than approximately (50 ± 20) Ω.

6.8 Capacitance Measurement

Warning: Input voltage is prohibited in this range.

1. Insert the black test lead into the "COM" socket and the red test lead into the "V Ω" socket.
2. Press the "SELECT" key to switch to the capacitance function.
3. If the measured capacitance exceeds the maximum range, "OL" will be displayed.
4. Before testing, fully discharge the capacitor to prevent damage to the instrument.
5. If no capacitance is measured, a base number may be displayed. Press the "ZERO" button to reset it to zero before measuring.

6.9 Frequency Measurement

1. Insert the probe or shielded cable into the "COM" and "V Ω" sockets.
2. Press the "SELECT" key to switch to the frequency function, and connect the probe or cable to the signal source or tested load.
3. If the input exceeds 10Vrms, it can be read, but may exceed tolerance.
4. In noisy environments, use shielded cables for small signals.
5. When measuring high voltage circuits, pay special attention to avoiding electric shock.
6. Do not input voltage values exceeding 250V DC or AC peak to avoid damaging the instrument.

6.10 Temperature Measurement

1. Press the "SELECT" key to switch to the temperature function.
2. Insert the negative end of the K-type TP01 thermocouple into the "COM" port and the positive end into the "V Ω" hole.
3. The temperature measurement range is -20 to 1000 °C. If it's too large, "OL" will be displayed.
4. Do not replace the temperature sensor arbitrarily, as it may affect accuracy.
5. It is strictly prohibited to input voltage in the temperature range.

6.11 Non-Contact Voltage (NCV) / Live Wire Measurement

1. Press the NCV/LIVE key. The screen displays "EF" and enters non-contact electric field measurement mode.
2. Place the front end of the instrument near the AC voltage. The buzzer will emit continuous sounds at different intervals, and the LCD will display different segments, depending on the signal strength.
3. Press the NCV/LIVE key again in NCV mode. The screen displays "LIVE" to enter live line measurement mode.
4. Insert the red probe into the "V Ω" socket (single probe operation is sufficient). If the buzzer emits a continuous sound and "OL" is displayed, it indicates a live wire.
5. This function is applicable to frequency signals ranging from 50Hz to 1kHz.

6.12 Data Hold

Short press the "HOLD" key to hold the displayed data. Short press "HOLD" again to unlock the data.

6.13 Flashlight Function

To activate the flashlight, keep pressing and holding the flashlight button until it turns on. To turn it off, keep pressing and holding the button again.

6.14 Leakage Current Measurement

6.14.1 Detecting Leakage Current on Grounding Wire

1. Open the trigger and clamp the pliers around the grounding wire.
2. Check the reading displayed on the LCD; this is the leakage current value.

6.14.2 Single-Phase AC Leakage Current Detection

1. Open the trigger and clamp the power supply wires (wire, live wire, and zero wire) together with the clamp head.
2. The reading displayed on the instrument is the leakage current value.

6.14.3 Three-Phase Three-Wire Leakage Current Detection

1. Open the trigger and clamp the three live wires together with the pliers.
2. The reading displayed by the instrument is the leakage current value.

6.14.4 Three-Phase Four-Wire Leakage Current Detection

1. Open the trigger and clamp the three live wires and the zero wire together with the clamp head. Do not clamp the ground wire.
2. The instrument display reading is the leakage current value.

6.15 Automatic Shutdown

The instrument will automatically power off and enter a sleep state after 15 minutes of inactivity. A five-tone prompt will sound before shutdown. To restart, press and hold the power button for more than 2 seconds.

7. Maintenance

• Cleaning: Use a soft, dry cloth to clean the instrument. Do not use abrasive cleaners or solvents.
• Storage: When not in use for extended periods, store the clamp meter in its provided storage bag in a cool, dry place, away from direct sunlight and extreme temperatures.
• Battery Care: Recharge the internal lithium battery regularly, even if not in frequent use, to maintain its lifespan. Avoid fully discharging the battery for long periods.
• Inspection: Periodically inspect the test leads and the clamp head for any signs of wear, damage, or compromised insulation. Replace damaged components immediately.

8. Troubleshooting

If your instrument does not function properly, refer to the table below for common issues and solutions. If the problem persists, contact the repair center or dealer.

9. User Tips

• Leakage Current Measurement: The WINAPEX 268B is capable of measuring leakage currents to the ground. For accurate readings, ensure proper clamping as described in section 6.14.
• True RMS: This meter features True RMS measurement, providing accurate readings for non-sinusoidal AC waveforms.
• DC Current Zeroing: When testing DC current, it is crucial to press the "ZERO" key to clear any residual readings before clamping the object being measured. This ensures the most accurate measurement.
• Screen Visibility: Utilize the screen rotation and brightness adjustment features to optimize visibility in various working conditions.

10. Warranty and Support

The manufacturer warrants this product against defects in materials and workmanship for a period of one year from the date of purchase. This warranty does not cover damage caused by misuse, accident, unauthorized service, or other causes not arising from defects in materials or workmanship.

This manual is subject to change without notice. The content of this manual is considered correct. If users find any errors, omissions, etc., please contact the manufacturer. The company shall not be responsible for accidents and hazards caused by user error operations. The functions described in this manual are not intended as a reason for using the product for special purposes.

For further assistance or detailed information, please refer to the comprehensive user manual available in PDF format: WINAPEX 268B User Manual (PDF).