I have a WEN PowerPro 5500, rated at 5000W, 5500 surge, 20.5A. Has a socket for 30A plug. I also have a GenTran 20216 6-pole manual switch rated at 5000W, two are ganged together. The integral plug is a 20A design. The suggested installation instructions say 12ga. 4-wire, and I'd like to go 90ft across the basement, and across the garage to the door, all indoors. Is it permissible to have the different plug designs on opposite ends of the cable? Is 90 ft. too far? Home D had 600V rated cable that looked too thick for the plug designs, they had no lesser-insulated cable. The only ready-terminated cables they had were 25 ft. I will select 4 critical circuits along with the 220V for my well pump, to stay alive, and keep my wife (somewhat) happy during the inevitable next outage. Thanks for comments.