Are your wall outlets electrically coded for 20A or 15A? Consider that each uses a different gauge of wiring within the wall. If your outlet is 15A, you should probably use a 15A cord. 20A cord can carry more current, which would mean that it may not trip a 15A circuit breaker when it is supposed to. I am not an electrician, but an interested audiophile and this is what I have read.