Originally Posted by kok328
You'll have to check this to verify but, I think you have a dual circuit outlet w/a shared neutral. Check the old outlet to see if you have continuity between the two hot lugs (I suspect not). If you do; I'm temporarily stumped.
Also, coincidental contact is not proper for grounding. I'm interpreting that you have metal outlet boxes and there is a ground screw in the back of the box? In any case, you'll want to pigtail that ground wire and attach it to the outlet ground. If you have a dual circuit outlet, the you simply abandon one of the black wires and use the remaining to install the GFI. If you have any other GFI's in the home, you may want to see if the sink outlet isn't already GFI protected.
Thanks for the quick reply. I'll check to see if I have continuity b/w the two hots. Can I use my standard circuit tester or do I need to measure the volt difference between the two?
I agree coincidental contact (or even intentional contact via using a long screw) is awful. It's not a ground screw at the back of a metal box, rather, it's a copper wire that has a metal clip. This is common to the other outlets save for the fact that they have green ground wires coming out of them and this one does not. Next trip to the store and I'll buy a groun wire to connect to the copper wire in the back.
There are no other GFIs in the condo save for the ones I've installed.
I'll try abandoning the other black and cap it and see how that works.