I am renovating an old home(90 years) that my wife and I just purchased. The electrical system in the house is outdated – some of the outlets appear to be knob and tube but most are the brass and silver; forgive me if this is incorrect info, I honestly know very little.
To the point – We do not have grounded outlets and I started replacing the 2 prong outlets with 3 prong outlets (without installing the ground). I realized this is a bad idea and decided to start researching. I am a little confused because I hear opposing arguments on whether or not the GFCI outlets are able to compensate, to some degree, for the inability to short circuit on demand.
I have read that the GFCI are good for nothing more than water running into the outlet whereas the actual ground would short circuit if there was a problem with too much electric output or metal coming into contact.
My question is: Could I replace the 2 prong outlets with GFCI and call it good, or should I be installing a ground? I prefer not to overhaul and install a ground but please tell me if this is a terrible idea or not.
Thanks in advance😀
— UPDATE —
I see that some of the outlets are encased with a metal rectangular box and was wondering if I could ground the outlet(s) by running a bare copper wire to the metal rectangle box back to the ground screw on the outlet?
Pictures requested:
The Older Looking Outlet
The Newer Looking Outlet
On "The Newer Looking Outlet" above, you are not able to see it in the photograph but there is a green screw for grounding; it is on the bottom left hand side
Best Answer
Replace the outlets with GFCIs -- the operation of a GFCI in no way depends on the presence of the equipment grounding wire. You'll have to use the "No Equipment Ground" sticker that comes with them, by the way.
P.S. on the metal boxes -- since it sounds like your house is a mix of K&T and other wiring techniques (perhaps NM additions), you cannot ground to the boxes -- that technique only works if your house was wired with BX/AC, MC, or metallic conduit (RMC/IMC/EMT).
(Confirming that you have K&T and NM mixed in your house, based on your photos, by the way -- I also do not see a ground wire on the NM, but the angle of the photo makes it hard to tell.)