UNI-T UT271C Ground Resistance Tester Clamp คู่มือการใช้งานแอมมิเตอร์

1. บทนำและเรื่องอื่นๆview

ซีรี่ส์ UNI-T UT271 clamp ground resistance testers (UT271A, UT271B, UT271C) are advanced instruments designed for precise measurement of ground resistance, loop resistance, and AC leakage current. These devices are essential for ensuring the safety and proper functioning of electrical grounding systems. The UT271C model offers an extended resistance range up to 1000Ω and current measurement up to 20A, along with data storage capabilities and a synchronous display for resistance and current.

ภาพที่ 1.1: จบแล้วview of UNI-T UT271A, UT271B, and UT271C Ground Resistance Testers. These models offer varying measurement capabilities for ground resistance and AC current.

2. Key Product Features (UT271C)

• ช่วงกระแสไฟ AC: 0.01mA ถึง 20.0A
• ช่วงความต้านทาน: 0.010Ωถึง1000Ω
• การเปิดขากรรไกร: Φ32mm, suitable for most grounding busbars.
• การจัดเก็บข้อมูล: Capacity for 500 sets of measurement data.
• แสดง: Simultaneous display of Resistance (Ω) and Current (A) on a 4-digit LCD screen.
• การดำเนินการ: Quick self-check on startup and full automatic gear shifting for ease of use.
• ความเร็วในการวัด: Rapid measurement at 1 measurement per second.
• ใบรับรอง: ได้รับการรับรอง CE

Image 2.1: Detailed features of the UNI-T UT271C, highlighting its measurement capabilities and display characteristics.

3. อุปกรณ์เสริมของผลิตภัณฑ์

Upon unboxing your UNI-T UT271C, please verify that all the following accessories are included:

• Instrument (UT271C Clamp Meter): 1 unit
• Standard Test Loops: 1Ω and 10Ω (1 set)
• Warranty Card / Certificate of Conformity: 1 piece
• Cloth Carrying Bag: 1 piece
• Instruction Manual: 1 piece (this document)

Image 3.1: The complete set of accessories provided with the UNI-T UT271C, ensuring you have everything needed for operation and transport.

4. การตั้งค่า

Before using the UT271C, perform the following initial setup steps:

1. การติดตั้งแบตเตอรี่: The device requires DC 6V power, typically supplied by four No.5 alkaline dry batteries (LR6 1.5V X 4). Open the battery compartment on the back of the device, insert the batteries according to the polarity indicators, and securely close the compartment.
2. เปิดเครื่อง: Press the power button to turn on the device. The meter will perform a quick self-check on startup.
3. การปรับเทียบด้วยตนเอง: ให้แน่ใจว่า clamp jaws are fully closed and clean before powering on for accurate self-calibration.

5. คู่มือการใช้งาน

The UT271C is designed for straightforward operation. Follow these guidelines for accurate measurements:

5.1. Ground Resistance Measurement

1. Ensure the target grounding system is de-energized or safe to clamp.
2. เปิด clamp jaws and position them around the grounding conductor or busbar. The jaw size is Φ32mm.
3. Close the jaws firmly. Ensure there is no gap between the jaws for accurate readings.
4. The device will automatically select the appropriate range. The resistance value will be displayed on the LCD screen.
5. For loop resistance tests, ensure the loop is closed and clamp around the conductor forming the loop.

Image 5.1: Demonstrating the use of the 32mm circular jaw for measuring ground resistance on a conductor. The jaw is designed to fit around most standard grounding busbars.

5.2. AC Leakage Current Measurement

1. Select the current measurement mode if not automatically detected.
2. Clamp the jaws around the conductor where leakage current is to be measured.
3. The AC current value will be displayed on the LCD screen. The UT271C can measure currents from 0.01mA up to 20.0A.

5.3. การจัดเก็บข้อมูล

The UT271C can store up to 500 sets of measurement data. Refer to the device's specific button functions (e.g., 'MEM' button) for saving and recalling data. This feature is useful for logging measurements over time or across multiple test points.

6. การสมัคร

The UNI-T UT271C is a versatile tool with various applications in electrical engineering and maintenance:

• Power Grid Construction: Essential for checking the resistance value of grounding grids during construction or renovation of substations to meet safety standards.
• Transmission Tower Measurement: Used to measure the grounding resistance of transmission towers, providing a critical parameter for evaluating the effectiveness of grounding systems. Effective grounding protects equipment from electrical faults like lightning strikes and overvoltagใช่
• High-Rise Buildings: Necessary for installing lightning protection systems in high-rise buildings, ensuring accurate grounding resistance for effectiveness.
• Subway Construction Projects: Grounding resistance testing is required for electrical facilities in underground railway projects to ensure operational safety.

ภาพที่ 6.1: อดีตamples of the UT271C in practical applications, including measuring tower resistance, charging pile resistance, AC current, and leakage current in various electrical installations.

7. การบำรุงรักษา

Proper maintenance ensures the longevity and accuracy of your UT271C:

• การทำความสะอาด: Use a soft, dry cloth to clean the instrument. Do not use abrasive cleaners or solvents. Keep the clamp jaws clean and free of debris.
• การเปลี่ยนแบตเตอรี่: Replace batteries promptly when the low battery indicator appears. Always use the specified battery type (No.5 alkaline dry battery, LR6 1.5V X 4).
• พื้นที่จัดเก็บ: When not in use for extended periods, remove the batteries to prevent leakage. Store the device in its cloth bag in a dry environment with a temperature range of -20°C to 60°C and relative humidity below 80% RH.
• การสอบเทียบ: แนะนำให้ทำการสอบเทียบอย่างสม่ำเสมอโดยบุคลากรที่มีคุณสมบัติ เพื่อรักษาความแม่นยำในการวัด

8 การแก้ไขปัญหา

If you encounter issues with your UT271C, consider the following common troubleshooting steps:

• ไม่มีจอแสดงผล/เปิดเครื่อง: ตรวจสอบการติดตั้งแบตเตอรี่และให้แน่ใจว่าแบตเตอรี่ไม่หมด เปลี่ยนแบตเตอรี่หากจำเป็น
• การอ่านค่าที่ไม่ถูกต้อง: ให้แน่ใจว่า clamp jaws are fully closed and clean. Verify that the conductor is properly centered within the jaws. Check for external electromagnetic interference.
• "Low Battery" Prompt: เปลี่ยนแบตเตอรี่ทั้งสี่ก้อนด้วยแบตเตอรี่ใหม่
• Interference Indication: The device automatically identifies interference signals. If the interference current is high, a "Noise" symbol will be displayed. Try to minimize external electrical noise sources.

หากปัญหายังคงอยู่ โปรดติดต่อฝ่ายบริการลูกค้าของ UNI-T

9. ข้อมูลจำเพาะ

Image 9.1: Comprehensive technical specifications for the UT271 series, including ranges, resolutions, and accuracies for each model.

10. กฎระเบียบด้านความปลอดภัย

The UNI-T UT271C complies with the following safety and verification regulations:

• IEC61010-1 (CATII 300V, CATIV150V, pollution level 2)
• IEC61010-031
• IEC61557-1 (Grounding Resistance)
• JJG 1054-2009 Verification Regulations for Clamp on Grounding Resistance Meter

Always adhere to local safety regulations and best practices when working with electrical systems. Do not use the device if it appears damaged or is operating abnormally.

11. การรับประกันและการสนับสนุน

UNI-T products are manufactured to high-quality standards. For warranty information, please refer to the warranty card included with your product. In case of technical issues, repair, or calibration needs, please contact UNI-T customer support or your local distributor. Keep your purchase receipt as proof of purchase for warranty claims.

ผู้ผลิต: UNI-TREND TECHNOLOGY (จีน) บจก.