I’ve got an old house with some old wiring. There is outlet that is non-polarized and non-grounded where I need to plug in a computer. I can use an adapter for the grounding issue but I can’t plug in the adapter as the outlet isn’t polarized. Can I just replace the outlet with a modern one that is polarized (and grounded I couldn’t find any non-grounded outlets at my big-box store) so I can plug in my modern appliance with out replacing the cable (i.e. keep in the old two wire cable and just leave the outlet non-polarized an not attache the ground terminal on the outlet)?
Thanks, M
Replies
A computer is probably something that you want to have grounded.
You should not replace a two-prong ungrounded receptacle with a three prong receptacle if there is no ground wire to be attached.
I believe your two options are:
1) Get a polarized two-prong receptacle (I am fairly certain I saw these at Lowes a month or so ago so you may just need to check a different store), and use your adapter.
2) Replace the receptacle with a GFCI receptacle. This is an allowed method to install a 3 prong receptacle when there is no ground wire present. You should put the supplied "No Equipment Ground" sticker on the receptacle and any other receptacles it feeds.
#2 is iffy in my mind because I wonder if your computer or monitor will cause it to trip. Someone else may have some better advice on this front.
i type by hunt and peck,so 15 minutes to write that post and you beat me to the punch line by 3 mins.. man i gotta learn to type faster!!!!! larryif a man speaks in the forest,and there's not a woman to hear him,is he still wrong?
1) It sure feels a lot better to be on the winning side of the race for once.2) Now when someone smarter like Bill comes along and points out something I said wrong, you have to feel bad too since you said the exact same thing! :-)
not me i'm going to hit delete when it hits the fan,i'm leaving you hanging by yourself !!! larryif a man speaks in the forest,and there's not a woman to hear him,is he still wrong?
ok,someone with master electrician will be along soon,but i'll give you a shot. first whenever you use a adapter in a 2 prong outlet to plug in a 3 prong,you are kidding your self that it's grounded. now if the outlet box is geounded and you take the plate screw off and reinstall it thru the adapter,your probably grounded. lots of if's though.
now you can buy a new 3 prong outlet for .44 cents and replace,but you still have no ground just that the plug now fits. make sure polarity is right. as far as i'm concered this is the worst thing to do ,somebody comes along and thinks their grounded and they are not.but at least the polarity is right..
now if you look at the big box real hard you will find a 2 prong plug,cost about 3.00. again no ground,but right polarity,so thats a plus.
what i would do is install a cfi plug.right polarity,no ground req. and protection from shock,i'm not sure it helps your computer though. the plug will come with a decal that you need to put on the cover that states"no equipment groung" so nobody assumes they have a ground.
best ,run a new line from box tocomputer with ground and dedicate it for computer.larry
if a man speaks in the forest,and there's not a woman to hear him,is he still wrong?
You can still get non grounded receptacles, i've bought them at Lowes as recently as last January.
I got lucky on my project. 90% of the wire I had to deal with was sheathed in BX which gave me continuity back to the box to allow grounded outlets.
The three that had no continuity remained 2 prongers.
Family.....They're always there when they need you.
What kind of wiring i there now? If its BX the system is grounded through the armor. Just install a new outlet and screwing it to the box will ground it.
1) You can legally replace a 2-prong outlet with a 3-prong GFCI outlet, if you label the outlet "No equipment ground".
2) If you look in the right place you can find replacement polarized 2-prong outlets.
If you do replace the outlet with either of the above, you should use some sort of tester to determine which wire is hot (don't trust the color coding of the wires, if any), and make sure the hot wire is connected to the brass screw.
Generally, though, with computer equipment you should have a "real" ground.
The home horror stores should have should have ungrounded polarized receptacles.
Now if you have metal boxes and Armoured cable (so called BX) or metial conduit then the box is grounded. In that case a grounded receptacle can be installed.
You can install a ground screw in a tapped hole in the box or there is a slip on clip that you can use. Then install pigtail to connect the ground on the receptacle.
Or you can install a GFCI receptacle and it will give you a ground style receptacle, but with no connection on the ground pin. And you are suppose to install a lable that says "No Equipment Ground". That gives you the same personal safety as a true ground. But for maximum protection with a surge protector you need a true ground.
Other than the grounded box as I mentioned above to get a true ground either run a new circuit with a ground.
Or you are allowed to run a ground only wire and run it to an other box that has a ground or back to the main panel.
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A-holes. Hey every group has to have one. And I have been elected to be the one. I should make that my tagline.
Thanks all. Installed and tested. Used the mx as ground. Worked great!
Gotta be careful assuming the BX goes all the way home. In the last house I did, continuity was broken all over the place.
Test the outlet after (before) and make sure you have ground continuity.
Family.....They're always there when they need you.