UNI-T UT251C Current Leakage Clamp Meter Instruction Manual

1. Product Overview

The UNI-T UT251C is a high-accuracy, high-sensitivity leakage current clamp meter designed for precise measurement of AC leakage current. This instrument is suitable for various applications, including checking leakage current in motors, home appliances, and other electrical equipment, with a measurement capability up to 600A.

Image: UNI-T UT251A and UT251C models.

2. Key Features

• Display: 4-digit LCD digital display with 10000 count.
• Measurement: Auto range for current measurement.
• Sampling Rate: 2 samples per second.
• Data Functions: Peaks hold and Data hold capabilities.
• Data Storage: Stores up to 99 sets of data.
• Connectivity: RS-232 interface for data transmission.
• Power Management: Auto power off feature.
• Indicators: Overload indication and low battery indication.

3. What's in the Box

Upon unpacking, please verify that all standard accessories are present:

• UNI-T UT251C Clamp Meter
• Instruction Manual
• Battery
• Charger (if applicable)
• RS-232 Interface Cable

If any items are missing or damaged, please contact your supplier immediately.

4. Setup

4.1 Battery Installation

1. Ensure the meter is powered off.
2. Locate the battery compartment cover on the back of the meter.
3. Use a suitable screwdriver to open the cover.
4. Insert the battery, observing the correct polarity (+/-).
5. Replace the battery compartment cover and secure it with the screw.

4.2 Powering On/Off

• To power on the meter, press the POWER button.
• To power off the meter, press and hold the POWER button until the display turns off. The meter also features an auto power off function to conserve battery life.

5. Operating Instructions

5.1 Measuring AC Leakage Current

1. Power on the meter.
2. Open the clamp jaw by pressing the trigger.
3. Carefully place the conductor (e.g., power cable) within the clamp jaw. Ensure the jaw is fully closed around the conductor. For accurate leakage current measurement, clamp around both the live and neutral conductors of a single-phase circuit, or all phase conductors of a multi-phase circuit.
4. Read the leakage current value displayed on the LCD screen.

Image: Clamp meter in use, measuring current.

5.2 Data Hold Function

To freeze the current reading on the display, press the HOLD button. Press it again to release the hold and resume live readings.

5.3 Peak Hold Function

The Peak Hold function captures and displays the maximum peak value of the measured current. Refer to the specific button on your device for activating this feature.

5.4 Data Storage

The meter can store up to 99 sets of measurement data. Consult the detailed manual for specific instructions on how to save and recall data sets using the device's interface.

5.5 RS-232 Data Transmission

The RS-232 interface allows for data transfer to a computer for further analysis or logging. Connect the meter to a computer using the provided RS-232 cable and use compatible software (not included) for data communication.

6. Maintenance

6.1 Cleaning

Wipe the meter's casing with a damp cloth and mild detergent. Do not use abrasives or solvents. Ensure the meter is dry before storage or use.

6.2 Battery Replacement

When the low battery indicator appears on the display, replace the battery promptly to ensure accurate measurements. Refer to section 4.1 for battery installation instructions.

6.3 Storage

When not in use for extended periods, remove the battery and store the meter in a cool, dry place, away from direct sunlight and extreme temperatures.

7. Troubleshooting

• No Display/Meter Not Powering On: Check battery installation and ensure the battery has sufficient charge. Replace if necessary.
• "OL" Indication (Overload): The measured current exceeds the meter's maximum range. Remove the clamp from the conductor immediately to prevent damage.
• Inaccurate Readings: Ensure the clamp jaw is fully closed around a single conductor or a bundle of conductors for leakage measurement. Avoid external magnetic fields.
• Low Battery Indication: Replace the battery as soon as possible to maintain measurement accuracy.

8. Specifications

Image: UNI-T UT251C model with key specifications.

Image: Comprehensive specifications for UT251 series.

9. Warranty and Support

The UNI-T UT251C Current Leakage Clamp Meter comes with a 1-year warranty from the date of purchase. For warranty claims, technical support, or service inquiries, please contact your authorized UNI-T dealer or the manufacturer directly. Please retain your proof of purchase for warranty validation.