电气 什么是selv和pelv？felv是什么意思保护特低电压pelv (protective extra low voltage, 缩写 pelv) ，只作为保护接地系统的安全特低电压用防护。安全特低电压 selv (safety extra low.
The New Cosby Show What They Don't Want You to Know HubPages
Extra Phun Explained: What They Don’t Want You To Know Stuff Don't By Ben Bowlin Matt Frederick Noel
