One of the first things people get confused about when trying to install an electrical outlet is which way is right side up! While it’s a topic heavily debated among electricians, the bottom line is, it doesn’t matter if you install the outlet with the ground hole up or down—technically. The electric code doesn’t require a certain direction. But that’s not where this topic ends.
The main reason there is so much debate is because electricians rely on the type of equipment that will be plugged in to determine the orientation of the electrical outlet. For instance, clothes washers, refrigerators and window air conditioners most commonly have cords with immediate-turn plugs, and so the logical way to install the outlet would be to orient it so that the plug inserts without having to loop over itself.
In terms of horizontal receptacles, your best bet is to place the grounding slot to the left and the wide neutral slot on top. The logic behind this move is all about safety. If an accident occurs where a metal object falls on the partially exposed blades, the item will land on the grounded neutral blade, which is safer than hitting the hot blade.
If a loosely plugged in cord were to have a metal object dropped on it with the ground slot at the bottom, the object can hit the power contact and short. Especially if you have kids around, this is something you want avoided at all costs!
The reality is, just because most of us have grown up with the ground prong slot at the bottom of our electrical outlets doesn’t mean it always makes the most sense! Many people revert back to the fact that there is no code-required orientation, but there are reasons for both orientations, so choose wisely.