What is the purpose of the neutral circuit in a newer 240 volt electrical system? I just bought a generator (Generac GP6500) and it has a 4 prong receptacle for the 240 volt connection. I can't find an adapter to convert this to a standard 3 prong plug. Is the neutral actually necessary? Can I make a cord that is 3 prong on one end, 4 prong on the other and eliminate the neutral?