cross-posted from: https://lemmy.nz/post/28693796
Check the comments of the original post for the stupidity.
For those of you without an electrical background, the diagram shows the protective earth connected directly to phase, with phase and neutral also joined.
Correctly wired, this would be a three pin plug, with the earth wire connected to the earth pin in the plug, with the other end connected to the metal casing of the appliance. This is a critical safety feature, which will cause the circuit protection to trip in the event a phase wire contacts the metal of whatever this is connected to.
If this was actually done, the most likely outcome is it would trip a circuit breaker, but if the neutral was broken, it would connect phase directly to the casing, and likely electrocute someone.
In the US, split-phase 240v appliances, like dryers and electric ranges, often do not come with a plug pre-wired. This is because older homes lack a ground on the outlet side. 240v works in the US by having two (120v) hots which are 180 degrees out of phase. Outlets in older homes have 3 sockets. Two lives (black and red) and a neutral (white). Outlets in newer homes have 4 sockets. The same 3 from above as well as a ground (green or bare). Normally you buy a pre-fabricated plug and do the wiring on the appliance side but you still need to match the right prong to the right terminal.
Of course, replacement plugs are also a thing if the original becomes damaged.