What Is a Withstanding Voltage Tester?
A withstanding voltage tester is a testing device used to evaluate the voltage endurance of electrical equipment and electronic components. It ensures that products operate safely within their rated voltage and design specifications. Materials with defects or impurities may lose dielectric strength, leading to the risk of dielectric breakdown when high voltage is applied, potentially causing electric shock or fire. The Electrical Appliance and Material Safety Law sets voltage withstand standards for devices to prevent such disasters. These tests, based on various standards and criteria, assess compliance with the law’s standards.
Uses of Withstanding Voltage Testers
Withstanding voltage testers are employed in a range of industrial fields, primarily for testing electrical products. They are crucial in evaluating the insulation performance of household appliances, like televisions and refrigerators, against overvoltages and voltage fluctuations. In power conversion equipment such as inverters, these tests check insulation capability against high voltages and waveform changes.
In the realm of electronic components like capacitors, withstanding voltage testers are used to assess insulation structures by applying voltages exceeding their rated capacity. For transistors and diodes, the tests verify proper insulation under operational conditions. Additionally, these testers play a vital role in ensuring the safety of medical devices and protecting patients and medical personnel from electric shock risks.
Principle of Withstanding Voltage Testers
Withstanding voltage testers generate and apply high voltages to test objects. Typically employing transformers or power amplifier circuits, they boost low voltages to high levels for application to the test objects. Equipped with measurement circuits and sensors, these testers evaluate the insulation performance by measuring parameters like leakage current and insulation resistance. This confirms the object’s insulation capability and withstand voltage limits. Additionally, these testers often have functions to control the voltage signal’s waveform and characteristics, enabling precise test conditions like sustained voltage application and test duration settings.
How to Select a Withstanding Voltage Tester
Selecting the right withstanding voltage tester involves considering factors such as voltage range, testing standards, and measurement capabilities, all within a budget. Key considerations include:
1. Maximum Withstand Voltage
The tester’s voltage range should align with the test object’s maximum voltage requirements, including the accuracy of voltage control and the applicable voltage type (AC/DC). The equipment’s specifications must be checked for the needed accuracy.
2. Testing Standards and Regulatory Requirements
Test standards and regulatory compliance, ideally to international standards like IEC or industry-specific ones, are crucial. The required voltage level, test duration, and conditions may vary by standard.
3. Measurement Functions
Ensuring the tester has essential measurement functions, such as leakage current and insulation resistance measurements, is important. Protective features like overcurrent shutdown should also be verified.