In today’s world, people can hardly live without electrical appliances. Whether it is cooling in the summer, heating in the winter, washing and cooking, communication, all aspects of human life are tied to electricity. However, I believe that everyone is familiar with news about dangers caused by various types of electric shock. Living in a world where convenient and fast electrical appliances are everywhere is a double-edged sword. While we enjoy the convenience provided by electrical appliances, we are also constantly exposed to potential safety hazards. To avoid hidden dangers, electrical appliances need to be strictly inspected and tested before leaving the factory for use.
The most basic safety and performance test for electrical appliances is the hipot test. During long-term operation, electrical appliances not only have to withstand the effect of the rated working voltage, but also the effect of overvoltage that is higher than the rated working voltage for a short period of time during operation (the overvoltage value may be several times higher than the rated working voltage value). . Under the influence of these voltages, the external structure of the electrical insulation material will change. When the overvoltage intensity reaches a certain value, the insulation of the material will breakdown, the electrical appliance will not be able to operate normally, and the operator may get electric shock, endangering personal safety.
The equipment required for this process is the hipot tester.
How the hipot tester works
During the hipot test, a voltage higher than the normal working voltage is applied to the product for testing. This voltage must last for a specified period of time. If the leakage current of a component remains within the specified range within the specified time, it can be determined that the component is operating under normal conditions and should be very safe. And good design and selection of good insulation materials can protect users.
For ordinary appliances, the hipot test is to test the breakdown current between the front line and the chassis. The basic rule is to use twice the working voltage of the object under test plus 1000V as the test voltage standard. The test voltage of some products can be higher than twice the working voltage +1000V. The hipot tester is small in size, good in quality, and convenient for customers to install.
There are different types of hipot testers for buyers to choose from Push,China’s leading supplier of tester.
Vlf Hipot Tester
VLF stands for very low frequency. The Vlf Hipot Tester is an AC output high-voltage instrument. The output voltage of the Vlf Hipot Tester is sinusoidal AC, but the frequency is only 0.1Hz – 0.01Hz, while the output frequency of the traditional AC tester is 50/60Hz.
The output voltage remains an AC voltage, with the sinusoidal polarity reversing every half cycle. Vlf Hipot Tester are used to perform simple yes/no or pass/fail withstand voltage tests. At the same time, the ultra-low frequency tester can also be used as a voltage source for offline cable diagnostic partial discharge testing and dielectric loss testing.
Vlf Hipot Tester 45kv is a common specification of Vlf Hipot Tester.
Ac dc hipot tester
The ac dc hipot tester exposes a product to a very harsh electrical environment. If the product can maintain normal conditions in such a harsh electrical environment, it can be determined that it can also operate in a normal environment and maintain a very normal situation.
The AC and DC withstand voltage test basically applies a voltage higher than normal operation to the product. This voltage must last for a specified period of time. If the leakage current of a component remains within the specified range within the specified time, it can be determined that the component is operating under normal conditions and should be very safe.
Transformer hipot tester
The transformer hipot tester is the most effective and direct method to identify the insulation strength of power equipment. The transformer hipot test is divided into preparation work and test operation. The transformer hipot test is also a destructive test.
The transformer hipot test should comply with the following regulations:
1. For transformers with a capacity of less than 8000kVA and a winding rated voltage of less than 110kV, the line end test should be conducted according to Table 1.
2. For transformers with a capacity of 8000kVA and above and a winding rated voltage below 110kV, if test equipment is available, the line-end AC withstand voltage test can be carried out according to the voltage standard in Table 1;
3. For transformers with winding rated voltages of 110kV and above, the neutral point should undergo an AC withstand voltage test. The test withstand voltage standard is 80% of the factory test voltage value.