I need three holes. Give it to me.

September 24, 2007 1:29 PM

How can I convert a two-prong plug to a three pronged plug?

Just moved to a new place, and the outlet in the living room is two pronged. Of course, most of my things are three-pronged.

I realize I can get one of those orange adapter things which would allow my things to work, but from what I know of electrical stuff (which is pretty much nothing) that it would offer no protection from a surge because that third prong is a ground wire or what have you. Even if I plug a power strip into the adapter.

So, my question is, is it possible to convert a two prong plug into a three pronged plug? Bonus points for making it easy.

posted by sephira to Home & Garden (25 answers total)

Some adapters have a little hangdowny bit that you can screw onto the center screw of a two outlet plate. The center screw should ground the outlet once fully screwed in, but depending on the age of the wiring, and the electrician, this isn't guaranteed.

They look like this (just a google result, you can find them at hardware stores).
posted by JeremiahBritt at 1:33 PM on September 24, 2007

On the adapter there is a wire thing that should be screwed into the outlet with the cover plate screw. You should require nothing more complicated than that.
posted by JJ86 at 1:36 PM on September 24, 2007

Those orange adapters have a little tab that you're supposed to screw down with the screw that's in the middle of the outlet. That will (supposedly) ground the adapter.

For a more permanent, safer solution, you (or, rather, a qualified electrician, given your professed lack of experience with electricty) could take out the two-pronged outlet and replace it with a three-pronged one.

These two solutions assumed that there is some sort of ground going to the box that the two-pronged outlet is in. If there isn't, the box will have to be rewired.
posted by marionnette en chaussette at 1:36 PM on September 24, 2007

In all my experiences, the third prong is, in fact, redundant. When I have a three-pronged plug that needs to fit into a two-pronged socket, I use pliers to just get rid of the third. Haven't had any problems up to about 1500 watts on one extension cord with the third prong removed.

As for grounding, I'm no electrician either, but I've experienced surges and outages (not caused by my plugs, just bad source electricity) and no problems. I probably wouldn't trust it for my computer, and would buy a surge protector power strip, but that's because I love my computer and don't have the money for a new one, so I'm paranoid. ;)
posted by po at 1:37 PM on September 24, 2007

gif.
posted by acro at 1:39 PM on September 24, 2007

The ground doesn't protect against surges nearly as well as a surge strip. Mostly they protect you from death; either because a wire somewhere got loose or worn through making your appliance a big joy buzzer, or from fire if you have umpteen billion surge-strips plugged into one another.
posted by JeremiahBritt at 1:39 PM on September 24, 2007

The third "prong" isn't there to protect you from surges - it's there to prevent you electrocuting yourself if a hot wire should come in contact with the metal parts of whatever appliance your using.

The best solution is to open up the outlet and see if their is a ground wire in there. If so, then simply replace the outlet. If not, then it's not simple anymore.
posted by Neiltupper at 1:39 PM on September 24, 2007

If you live in a city that uses solid metal conduits to enclose the wires, you can simply replace the socket with a new one from home depot. Like Neiltupper said, if there is a green wire hanging in the box, that is your ground wire. Most likely there is not one. The third hole is the ground. If you have metal conduit, the box, conduit serve as the gound wire and go back to the main box and hopefully to a big copper wire connected to a bigger spike that goes into the ground, the earth.

I am not an electrician, but I did play one on Melrose Place in the 90's. Got to sleep with Courtney Thorne-Smith too!!
posted by lee at 1:52 PM on September 24, 2007

The third prong is redundant like seat belts are.

The prong to the centre screw only works if the box is grounded. Those little plug in electrical testers will let you know if in fact you are grounded after installation. If is fails the best thing to do (besides upgrading your wiring) is to run an extension from a grounded outlet.
posted by Mitheral at 1:53 PM on September 24, 2007

If the ground wire is not there, you can replace the outlet with a 3-prong GFCI outlet. These aren't terribly expensive anymore and provide better safety anyway. If you have no idea what you're doing, call an electrician.
posted by chairface at 1:54 PM on September 24, 2007

If you rent talk to your landlord…
I lived in a 30+ year old home in CT that had NO 3 prong outlets – actually the living room outlet was suspended in the wall (not attached to the wall) and if ever we moved the wires plugging into the outlet we risked the power turning off, not disconnected it would just turn off until I moved the wires and it turned back on. SUPER SAFE.

If you rent I believe your landlord should have to upgrade for safety.
posted by doorsfan at 2:02 PM on September 24, 2007

The best solution is to open up the outlet and see if there is a ground wire in there.

Hmm; I agree, but given their apparent knowledge of home electricity ("ground wire or what have you"), I wouldn't advise the poster to open anything up or wire anything up without direct help from someone who knows what they're doing.

As an aside, as the house I used to rent taught me, just because there is a 'ground' wire, doesn't mean it necessarily is connected to ground. Testing that is a little harder though (my housemate had a UPS with a 'ground fault' light that was continuously on; also whenever I leaned against a water pipe while touching the back of my computer, I got a bit of a shock. Good times.)
posted by blenderfish at 2:07 PM on September 24, 2007

Definitely at least ground the adapter to the socket, or better yet get the outlet rewired (as many other folks have said).

Don't remove the ground prong. Those aren't just for show (if they were, they'd be prettier).
posted by Nabubrush at 2:11 PM on September 24, 2007

The third prong is redundant like seat belts are redundant.

I would disagree on both counts.
posted by Neiltupper at 2:50 PM on September 24, 2007

If the house is wired with metal coated cable, you can use the metal covering as the ground (this is how attaching the adapter to the cover plate screw works) provided the outlet box is metal. You could also replace the outlet with a standard three prong plug and attach its ground to the box with a grounding pigtail.
posted by buttercup at 2:58 PM on September 24, 2007

Neiltupper writes "I would disagree on both counts."

Obviously I wasn't clear. Neither are redundant. Just because you haven't been injured because you (cut the prongs off/removed the seat belts from your car) doesn't mean (cutting the prongs off/removing the seat belts from your car) is a wise, prudent or safe action.
posted by Mitheral at 3:30 PM on September 24, 2007

Never, ever, EVER remove the third prong or do what po says. A few years ago I read about a high school student who was killed when he plugged a fan into the wall after snipping off the third prong so it would fit the outlet. Don't use 2-prong extension cords with 3-prong plugs either.
posted by ethnomethodologist at 3:46 PM on September 24, 2007

po's post flagged as "other" for lack of a "slightly life threatening" flag. As others have said, don't cut off or otherwise bypass the ground pin. There is a small chance of an extremely regrettable outcome.
posted by tss at 3:56 PM on September 24, 2007

I agree, po's comment is not just unhelpful but dangerous.

Removing the third prong is asking for a shock -- or a fire. This is a common "folk" remedy for the problem, but it is eminently unsafe.

There is unfortunately no guarantee that a three-prong adapter will fix your problem if your outlet is improperly grounded to begin with -- and many two-prong outlets have no effective grounding at all.

The safest thing here is to ask your landlord if he'll upgrade your outlets using a professional electrician; say you'll pay halfsies or something like that. It's possible to replace your own outlets, but technically while that's legal for a homeowner it isn't legal for a renter (and I wouldn't want my tenants doing it), and you wouldn't be sure you're getting a grounded three-prong in the end. An ungrounded three-prong receptacle that somebody thinks is grounded is arguably worse than what you have.
posted by dhartung at 4:16 PM on September 24, 2007

IAAE: If you remove the ground prong and the internal wiring of the appliance comes loose and the exterior of the appliance is energized YOU may become the return to ground (or earth for our UK friends) for the current. Chances are it will be rare but the reason the prong exists is because it happens. Anything else I could add would just be duplicating dhartung's advice.
posted by Kensational at 4:42 PM on September 24, 2007

Response by poster: I have no plans to take any tools to my television or Xbox, even if it's to the plug. No thanks. Based on instinct and what's been said here it's bad, life-threatening advice, not to mention I'd feel as if I were disfiguring my children.

The landlord's opinion is that I should just get a really long extension cord. Yes, this works, but it's an unsightly, inelegant solution.

All assumptions that I know squat about electricity are entirely understated; so replacing the outlets is right out. So, I'm going to go the adapter route, in the event of a misfortune befalling my electronics, there's always a warranty and renter's insurance to fall back on. Even if it doesn't, it sure beats being in the papers for killing myself after removing the third prong.

Thanks for the help, everyone!
posted by sephira at 6:46 PM on September 24, 2007

sephira make sure the adaptor is actually grounding otherwise the risk isn't to your electronics and rather to yourself. A plug in tester is cheap.
posted by Mitheral at 7:43 PM on September 24, 2007

Obviously I wasn't clear. Neither are redundant

My apologies Mitheral. Too cursory a reading on my part.
posted by Neiltupper at 8:51 PM on September 24, 2007

There are two funny things about electricity: 1) it's invisible and 2) it can kill you.

If you go the adapter route assume that your electronics are NOT grounded and treat them as such.

That tab which you screw into your face plate? It's mainly there to keep the adapter from pulling free of the outlet after you weigh it down with a heavy three prong plug.

If you go the extension route use only quality cords - there is no harm in buying a heavy duty appliance cord (one suited for running air conditioners, etc) even if you're just running your TV. Check the cord routinely - if it feels warm you should replace it with something more substantial.

When in doubt defer to professionals.
posted by wfrgms at 9:42 PM on September 24, 2007

An extension cord is dangerous and unsafe. Get the plug-in tester mentioned above and install a three-prong adapter, then check to see if it really is grounded. If not, your landlord needs to have a grounded outlet installed. Bug them about it until they do, mentioning fire safety and liability.
posted by Mr. Gunn at 9:44 AM on September 25, 2007