I have two 220 machines running in the garage. I do not want to run them both at the same time but use the LUG as a switch so I can alternate between the machines from a single 30A breaker in the house. One machine is a 30A and the other is 20A. I was told to use a 30 amp main lug with 2 circuits and 4 spaces and put a 20A breaker and a 30A breaker in it. I cant seem to find this product but a local box store has a 40A main lug 2 circuits 4 spaces. Can I put a 30A breaker in there and even the 20 amp breaker?