Most people think of electrical outlet receptacles as being properly installed when the two vertical slots are at the top, with the round grounding hole at the bottom. You may, though, see many installations that seem "upside-down," where the round grounding hole is at the top, with the vertical hot and neutral slots at the bottom.
In reality, there is no code requirement that says an outlet receptacle should be installed one way or the other. In fact, at one time some manufacturers actually recommended the orientation that many of us see as upside down—with the round grounding slot at the top. Many electricians still prefer this type of installation, for logical reasons.
Unlike wall switches, outlet receptacles do not have an up or down and will work just fine installed in either position. The only problem may be one of convention. Since outlets are more commonly installed with the ground holes on the bottom, it can be visually disturbing for some homeowners if they perceive their outlets as being installed incorrectly. But once you understand the reasons why this was done, you may want to leave them in place, or even change all your receptacles to be upside down.
Reasons for Upside-Down Installation
The National Electrical Code does not stipulate how outlet receptacles should be positioned within the electrical boxes. But some electricians install the receptacles with the ground slot facing upward, and there are several reasons why they do so:
To Identify a Switch-Controlled Outlet
Your outlet might turn on or off by a wall switch. This is valuable when you have a floor lamp you want to turn on when you enter a room. Some electricians will turn this outlet receptacle upside-down as a quick visual cue to indicate a switch-controlled receptacle. If your home has only one or two upside-down outlets, this may have been done as a means of identifying switch-controlled outlets.
To Promote Better Electrical Safety
Some people believe that this upside-down position reduces the possibility of electrical shock. In an upside-down position, if a three-prong plug comes partially out of the receptacle and a metal object should accidentally fall between the faceplate and the plug, the object will first hit the grounding prong. In the normal (grounding slot down) position, there exists the possibility of a dead short if an object falls into this space and bridges the gap between the hot and neutral prongs.
This is the logic that led some receptacle manufacturers to recommend this as the preferred orientation for receptacles. In hospitals, you may see all wall receptacles installed this way as a safety measure since a short circuit here can be a very serious matter indeed.
To Give Plugs a Better Grip
Some electricians and homeowners believe that a three-prong plug installed in this fashion holds tighter in the outlet. This point has some validity, but with the advent of TR (tamper-resistant) outlets, this point may soon become moot, as TR outlets provide a very strong grip on fully inserted plugs. Unfortunately, TR outlets have the opposite effect on partially inserted plugs, as the spring-loaded internal doors tend to push plugs out.
If you find your upside-down outlet receptacles to be visually disturbing, or if you feel that one of the above reasons is a good reason to mount them ground-slot-up, it is quite easy to change their orientation. It will cost you nothing to do so.
Tools and Supplies You Will Need
- Non-contact circuit tester
- Flat-head screwdriver
- Phillips screwdriver
Turn the Power Off
Go to your electrical service panel and turn off the circuit breaker that controls the circuit feeding the outlet. At the outlet, test for power using a non-contact circuit tester. (Make sure you understand how the tool works, and that its batteries are charged.)
Remove the Face Plate and Extract the Receptacle
- Once you have verified that the power is shut off, removed the face plate on the outlet by removing the mounting screw.
- Remove the top and bottom mounting screws that hold the receptacle strap to the electrical box.
- Carefully gripping the metal strap, gently pull the receptacle out of the box so that the wires straighten out. Be very careful not to loosen any of the wire connections. Most receptacles have enough wire to allow them to be pulled several inches out of the electrical box.
Rotate the Receptacle
Gently rotate the receptacle around 180 degrees so that it is now "right-side-up." Be very careful to avoid dislodging any connections as you rotate the receptacle. If you find it hard to rotate due to short wires, then it is best to completely disconnect the receptacle, rotate it, then reconnect the wires to the screw terminals.
Tug gently on the wires to verify that the wire connections are still secure on the receptacle's screw terminals.
Complete the Work
- Carefully tuck the circuit wires back into the electrical box and press the receptacle into the box.
- Thread the mounting screws on the device strap back into the screw holes on the electrical box, and tighten them down securely, making sure the receptacle is perfectly vertical.
- Reattach the outlet cover plate.
- Turn on the power and test the outlet to make sure it operates correctly. This can be done with the circuit tester, or by plugging in a lamp to make sure it operates.