Customers often call us and ask us that the voltage measured by your power supply casing with a multimeter is actually over 100V, and the safe voltage should be 36V, which can electrocute people. This issue has caused some customers to be hesitant to use it, so it is necessary to provide a separate explanation. In the filtering circuit at the internal inlet of the switching power supply, there is a capacitor with L.N to ground. When the casing is not grounded, the casing voltage is equal to the partial voltage of these two capacitors connected in series to 220V, which is 110V. However, due to the small capacitance value, it does not pose a threat to human health. Therefore, when using a switching power supply, we should ensure proper grounding to avoid unnecessary trouble and misunderstandings. There are two ways of grounding: 1. the shell is directly grounded; 2: The ground wire symbol on the wiring terminal is correctly grounded (as shown in the figure )