I have a Invision 456MP and Suitcase 12RC, I use the Program number 2 - 0 4 5 S t A r / C O 2

It has the options "Adaptive" Or "Non Adaptive" when I weld in "Adaptive"works perfect, but when I weld with "Non Adaptive" after a few seconds of welding, the voltage decreases alone.

Questions:
1 - When I weld in any program that Pulse at Invision 456MP I should use a feeder that Pulse (like the 60M Series) or my simple Suitcase could do it?

2 - When a welder could use "Non Adaptive" and what feeder him would use?

P.S. Sorry for my poor English, I'm for Brazil and my englis still is so basic.