Some Electricians Prefer the Ground Pin on Top
Another reason is simply installation preference.
There has long been debate among electricians about whether the grounding opening should face up or down.
Both orientations can be found in real homes and buildings, depending on local practices and individual preferences.
So you might walk into one house and find every receptacle oriented one way, while another home has them reversed.
And yes—sometimes the answer really can be as simple as:
That’s how the electrician installed them.
3. The Ground Pin Can Provide a Safety Advantage in Certain Situations
This is probably the most interesting argument for installing a receptacle with the ground opening on top.
Imagine a plug that is only partially inserted into the receptacle. If the plug were pulled or bumped and a metal object happened to fall onto it, the position of the grounding pin could potentially affect how the plug’s exposed metal portions interact with the receptacle.
With the grounding opening on top, some electricians argue that a partially inserted plug can be less likely to create a dangerous short circuit in certain scenarios.
This is one reason you may hear people say that ground-up installation is safer.
