Replacing a two-prong outlet with a GFCI


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Old 10-10-10, 02:35 PM
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Question Replacing a two-prong outlet with a GFCI

I have an old two prong outlet that I wanted to replace with a three prong outlet because we've put a desk next to it, it's the nearest outlet, and we want to plug in things with grounded plugs. I was pretty sure that the box wasn't grounded, so I thought I should go with a GFCI outlet so that I'd at least have some protection.
I got a GFCI outlet, turned off the power, and started removing the old two prong one. The instructions for the GFCI state that if you see anything more than 4 wires (not including ground) in the old box you should call an electrician. Of course, my old box appear to have 6 (and no ground at all). It looks like the old outlet has two pairs of terminals. The lower pair appears to be connected to the same cable coming into the box (it's a little tricky to tell, as the wires don't have much give and I can't pull it out too far) one is black and the other is brownish (presumably it used to be white?). The upper pair of terminal both have two separate wires connected to each of them.
I'm assuming the lower pair must be the line and the upper pair are the load, and for whatever reason, somebody decided to branch the load side and take it off in to different directions. Is it still okay to wire this up to a GFCI like this? Should I do as the instruction say, leave it well alone and call an electrician? I don't really want to pay somebody a lot of money just to tighten a couple of screw terminals!

Thanks.
 
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Old 10-10-10, 03:06 PM
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First off the GFCI outlet you are installing will give you more safety but does not provide you any type of ground. Although a ground is only there for safety anyway so this might be a wash.

If your goal is to only protect this outlet with the GFCI then just splice the blacks together and the whites together. Then pigtail off each splice (one black and one white) and connect the pigtails to the new outlets line side.

BTW - your are not just paying an electrician to turn a couple screws, your also paying for their knowledge. They could come and look at your box and determine if it is grounded or figure a way to get a real, legal ground. Its called a service.
 
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Old 10-10-10, 04:08 PM
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You said you are doing this to service a desk. If this is for a computer just be aware that surge protectors need a ground in order to work. Adding the GFI will not help in this aspect.

Given the number of wires in the box and that most of the older boxes were smaller it might be easier to add a GFI breaker instead of trying to fit too much into the box.

You also need t apply the "No ground" sticker to the faceplate.
 
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Old 10-11-10, 04:56 AM
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Thanks for the reply Tolyn

Originally Posted by Tolyn Ironhand View Post
First off the GFCI outlet you are installing will give you more safety but does not provide you any type of ground. Although a ground is only there for safety anyway so this might be a wash.
I'm aware of this.

If your goal is to only protect this outlet with the GFCI then just splice the blacks together and the whites together. Then pigtail off each splice (one black and one white) and connect the pigtails to the new outlets line side.
Is there any reason to do this versus just jamming two wires under the same terminal like the old one? There's not a lot of room in the box and the old cables aren't very flexible.

BTW - your are not just paying an electrician to turn a couple screws, your also paying for their knowledge. They could come and look at your box and determine if it is grounded or figure a way to get a real, legal ground. Its called a service.
Sorry, no offense intended.
 

Last edited by Tolyn Ironhand; 10-11-10 at 03:21 PM. Reason: fixed end qoute
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Old 10-11-10, 04:59 AM
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Thanks pcboss. I have a cheap laptop on the desk that needs a three pin plug for the charger. I'm aware that it ought to be grounded, but it's not and I don't have the money to get the house rewired (although I'd like to). I thought a GFCI would at least be better than nothing, or rather better than my current solution of using one of those 2 pin to 3 pin adapters (where the earth isn't connected to anything).
 
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Old 10-11-10, 03:26 PM
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Originally Posted by wjousts View Post
Is there any reason to do this versus just jamming two wires under the same terminal like the old one? There's not a lot of room in the box and the old cables aren't very flexible.
You may have only one wire per screw. Some GFCI devices have up to two holes per screw on each the line and load terminals but you would have to make sure your line and load of your wiring.



Originally Posted by wjousts View Post
Sorry, no offense intended.
None taken. I just wanted to make the point of why electricians can be expensive. There are other factors involved above pulling wire and making connections. carry on.
 
 

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