the appliance plugged into it works perfectly normally.
Does Ground-Up Mean the Outlet Is Wired Backward?
No.
This is an important distinction.
Physical orientation and electrical polarity are not the same thing.
You could have a receptacle installed with the grounding opening at the top and still have it correctly wired.
Likewise, a receptacle that looks completely normal could have a wiring problem.
You can’t determine whether an outlet is wired correctly simply by looking at which way it faces.
If you have concerns about a receptacle, the appropriate solution is electrical testing—not guessing based on its appearance.
What Actually Matters Inside an Outlet?
When it comes to electrical safety, several things are much more important than whether the outlet is “right side up.”
Correct wiring
The conductors need to be connected to the appropriate terminals.
Proper grounding
Where grounding is required, the grounding path needs to be properly installed
