I work in a power generation plant and I noticed that all the gauges have some kind of standard description at the bottom.
Some of them are easy to understand (I strongly suspect "~" means alternative), and I think the voltage here (220V) is the input voltage, but in general is there a guide to understand all those symbols? I searched on google, but I think I didn't use the right terminology because I didn't find anything.
Thanks for your help!