What is the difference between withstand voltage test and leakage current test?

In the safety inspection items, the current test item include withstand voltage test and leakage current test, and both tests are for the current of the insulating part. But in the actual test, there are many cases where both the withstand voltage test and the leakage current test need to be carried out. Why? And what is the difference between a withstand voltage test and a leakage current test?

Difference 1: voltage applied to the test is different.

The difference between the withstand voltage test and the leakage current test is mainly in the voltage applied to the EUT. The voltage applied in the withstand voltage test is much higher than the rated voltage, the test is between the live & neutral wire and the electrical enclosure, it mainly tests the insulation performance of the electrical appliance. The leakage current test is to apply a 1.06 times of rated voltage to EUT, and check if there is a leakage current between live wire and ground wire. Both of which are important items for electrical appliance quality inspection, are required to be tested by the national standard to ensure consumer safety.

Difference 2: The test purpose is different

The withstand voltage test is to check whether the product can withstand a certain strength of overvoltage, if the product can pass the withstand voltage test, it indicates that product has a strong ability to withstand voltage fluctuations during use, and it is not easy to cause problems such as self-damage. The leakage current test is to check if the current passing through the insulating part of the product (under normal working conditions) is lower than the safe current that human body can bear, if the product is qualified, it indicates that the product will not cause electrical damage to the human body during normal use.