Hi I bought a tig welder it was a monophase running on 3 phase got it home and the workshop I bought it from ad removed the 16 amp 3 pin plug because it was not pat tested. The problem for me is I took the cover off to change the brass connectors over to 240 volts following the diagram inside the welder .there is 4 wires going from the lead to inside blue /yellow. Green /black /brown ....yellow /green is going to a earth point. .Brown as been capped off ..black and blue are going to top of the switch .so how do I wire it up to a normal heavy duty plug. Which is the live and which is the neutral. Pls help will try to ad photos thanks