Ive managed to find the wiring diagram for a newarc wire feed unit that has the connections for a pot included. Newarc claim that there pedals and remote are compatible with there welders either mma or tig sets.
I would physically check that the wiring connections to the socket on the welder match either the diagram you were supplied or if it has the same connections as some of there other machines do. Looking at some of there other machines the 24vac is connected to pins 6 and 7 rather than the 1 and 2 from the diagram you have.