grounded (3 prong) vs ungrounded (2 prong) ac adapters?


Active Member
Feb 10, 2021
Is their any difference between them. i.e. between an ac adapter that takes a C5 cable (what I call the mickey mouse cable) vs an unpolarized C7 cable. In the US I preferred the C7 cables, but now that I'm overseas, wondering if I should stick with AC adapters that take a C5 and a 3 prong ground cable, or does it not really make a difference?u


Well-Known Member
Jan 26, 2014
I don't really know which is better, I have seen Lenovo AC adapters for the US market with a C7 cable which were double insulated, the equivalent European part was not double insulated and had a C5 cable (thus also using grounding).

I assume that if Lenovo is okay with shipping AC adapters without grounding but with double insulation, that they are essentially equivalent (probably with some cons/pros for each solution).

Obviously the third pin on the C5 is ground, so I am guessing it does not really matter too much, as long as you don't use a non double insulated adapter with a C5 plug without proper grounding (that said it will probably work just fine anyway - but at your own risk of course ;)).