The characteristics of the welder itself will not be changed.
The wire size will remain the same with the exception of the equipment grounding conductor, which with a 60A overcurrent protection could be reduced to a #10.
You've just had an easy hundred or two years of combined experience explain this to you.
Are you sure you want to put that 40Amp breaker in the subpanel? You've now gone from a matter of the manufacturer's recommendations at 80A OCPD with #8 to a 40A OCPD with #6??
Does your foreman have any reason that he can cite for the increased conductor size to #6? That's just nonsense.
sorry i probably didnt explain it clearly. but if you click on the image again it gives two choices on hooking up the welder.
-60a time delay fuses with 8awg conductor
or
-80a breaker with 8awg conductor
i couldnt find a 80a breaker so i want to use the 60a time-delay fuses. my question was, from the sub-panel to the 60a time-delay disconnect, can i use 8awg with a 40a breaker to feed the 60a time-delay disconnect??
thanks for your guys advice....