Hardware design issue

Author	Message
Mixtel90 Guru Joined: 05/10/2019 Location: United Kingdom Posts: 8964	Posted: 12:50pm 05 Dec 2024       Class X is rated to go across the supply lines, Class Y from a supply line to earth. It's the little ground cap that can give you a slight "tingle" from the low voltage output as it introduces a tiny amount of leakage. It's not a faulty supply. IIRC Class I power requires that one side of the output is connected to PE (mains earth). Class II is often called "double insulated" and there is no requirement for the output to be grounded, there is sufficient insulation from the mains. Many SMPS are of this sort, especially small ones. Then there's Class III which is extra low voltage (less than 60V) and has no requirement for earthing. It's considered to be safe to touch directly.