I've just finished installing a Siemens subpanel for my basement. Code requires arc fault interrupters for all circuits. The first breaker I installed was very loose- I'm used to having to push breakers on with some force- this just slid on and rocks while in position. Is this normal for these breakers, or for Siemen boxes? I tried multiple locations, and it didn't make much difference. I'm assuming this will cause a problem with arcing or flickering lights if I don't do something different, but I wondered for these slide on breakers, how tight is tight enough?