Quick question guys. I am not a licensed electrician but I do electrical work on the side, I'm a mechanical engineer by trade. I came across a minor issue on a job I did recently and I'm trying to determine the cause. My question is this: if you have a GFCI breaker installed (15A) is it OK to have GFCI receptacles installed on that circuit or could it potentially cause problems (as in one or the other tripping)? I understand that doing this isn't necessary and is a waste of money, but would it hurt?