groundingreceptacle
I have two-pronged outlets in my apartment. They look like this:
Is there a way to check whether they have a ground or not? Some guides talk about use a circuit tester and touching the screw, but I don't even see a screw? It seems like they've been painted over. Maybe I need to chip away at the paint?
On top of that, how would I even remove these?
- Check for unused grounding wire, and connect if found (great option, but I suspect we will not find such wiring based on the age of the building)
This is the only option that will actually provide equipment grounding, assuming you find an equipment grounding conductor in the box.
- Replace receptacle with ungrounded GFCI outlet
While this will provide ground-fault protection; which is good, it will not provide equipment grounding. In fact, when you do this you have to add a label that reads "No Equipment Ground" on each receptacle protected by the GFCI.
- Connect a ground wire from the outlet plug to it's box (presuming we discover the box is metal not plastic) and use the box for ground
This only works if the metal box is connected to an equipment grounding conductor, otherwise it offers no grounding at all.
- Ignore the lack of proper ground and cross our fingers none of our electronics get damaged
This is probably the most common solution. Though most people aren't ignoring the lack of grounding, they simply don't know they need it.
- Run an extension cord from a properly grounded outlet in a non-original part of the house to where the electronics will be?
This is a temporary solution, but you'd have to protect the cords from damage and use the proper size cord.
- Something else?
There's really not an easy solution here, the only way to do this is to run an equipment grounding conductor.
Other useful questions:
There should be no problem doing what you want.
One set of conductors brings power from an upstream device or outlet, while the other takes power to a downstream device or outlet. The two black conductors are electrically bonded through the receptacle, as are the two white conductors. You'll notice that the bonding tab on the side of the receptacle is still in place, which means that the two receptacles are connected together.
If you're simply replacing the existing receptacle, with an identical (or similar) receptacle of a different color. Simply connect the new receptacle exactly as the original is connected.
NOTE: When terminating conductors at a screw terminal, always wrap the conductor in a clockwise direction. This will cause the conductor to be pulled in tight, when the screw is tightened down.
I'm not sure what conductor combinations the supplied twist-on wire connectors are rated for, so I'm going to assume they're only rated for 2 #14 conductors (check the documentation). So before you start, you'll want to pick up a couple Ideal yellow twist-on wire connectors.
Best Answer
What's the point of making them grounded? Either a) safety or b) to plug in 3-prong plugs. There are several ways to do that.
You see the hole on your second photo? That's where the single screw goes. On your first photo, the screw is covered with many layers of paint.
I would not stick a spike in there and gore up the threads. Just get the proper screw. They come free with outlet covers, which cost 30 cents. Sand the paint off the head if you mean to put a voltage probe on it.
At this point, the layers of paint will have schellacked the outlet covers to the wall, and you'll need some careful knife work to separate them. Err on the side of damaging the outlet cover. They make oversize outlet covers for a neater appearance in this situation (not 30 cents). And next time you paint, take the covers off first.
Safety
If you can live with 2-prong outlets, you can render those safe by feeding them from a GFCI breaker or receptacle upstream. Since GFCI breakers cost more than receptacles, especially for some archaic panels, I have been known to put a receptacle inches away from the panel and feed the whole circuit from that. Plug a nightlight into every outlet in the house to make sure you don't have any crossed neutrals that would prevent the GFCI from working. Put "GFCI protected" labels on all protected receptacles.
3-prong outlets
If you have provided GFCI protection, it is legal to fit a 3-prong receptacle if you also add a sticker saying "No Equipment Ground". If that sounds like it doesn't protect equipment, exactly - some equipment cares about that for non-safety reasons, e.g. being sensitive to "static electricity" (ESD).
If you want real grounded outlets, and you don't have good ground in the junction box, you can retrofit ground. This is easier than pulling all new grounded cable, since it's a single bare wire, and since every circuit served out of the same panel can share ground wires. The only requirement is that the ground path be thick enough its entire length; so plan for this. Runs to your heavy appliances (range, dryer, water heater) can be a backbone for the other grounds to connect to.