I'm sorry MC5W. But lets not revive 5 year old threads.

Inverter welders can use lower amperages because of Arc force, but that will depend upon the settings. 90 amps is still 90 amps. It depends upon how the arc force is set. It still takes 120 Amps. You can get by with 90 amps if arc force is set correctly, but not recommended.

You don't use more the 25% Helium with our units. Arc will not be stable.