One more little ting to think about. sometime when you get a chance, take a good look at your actual plugs. Even though the blades are pretty big. the actual contact surface will be a lot smaller. With even an average load, the resistance at the contacts can create a lot of heat, which only makes the situation worse. Result? melted plugs and receptacles. Cure? inspect your plugs and clean them regularly. Get get rid of as much dirt and stuff as you can. Keep your plugs clean and shiny and a bit of contact lubricant helps also. Its a little thing but over time it can make a difference.
