Can I hook up a GFI If there is no ground wire?

Question

In a old house that has no ground wire

Answer 1

Yes and no. The GFI can be installed in the fuse panel pertaining to that part of house needing GFI protection, Thus the whole area is protected. Installing a GFI receptacle in that room without a ground wire, will not really work fully, even though the white wire is grounded.

Answer 2

A GFCI receptacle can be installed on any type of wiring system. The NEC requires that a GFCI receptacle, and any additional receptacles it protects, be labeled "NO EQUIPMENT GROUND". This is because, although you will be protected from a ground fault event, any "3-wire" equipment plugged into that receptacle will have no grounding connection. (Most GFCI receptacles have 4 - 6 of these labels in the box' along with a similar number that state "GFCI PROTECTED" - these are for use in kitchens or bathrooms where GFCI protection is required.) When “daisy-chaining” off of a GFCI receptacle, be certain to feed any other receptacles to be protected from the “Load” side of the device (if you are not going to do so, leave the tape over these terminals). For best results, if you are going to install individual GFCI receptacles on the same circuit, feed them from the “Line” side of the preceding receptacle.

If you install a GFCI type circuit breaker, the same rule applies, any 3-opening receptacles will require the same label be applied.

Should you have any sensitive electronic devices that must have an Equipment Grounding Conductor, the Code allows you to run a separate EGC (correctly sized, and green insulated or bare) from the receptacle's ground terminal (the green s***w) back to the panel or to an approved grounding electrode (back to the panel is best, then install the required grounding electrodes from NEC 250.50). This conductor must be bonded to the metallic box the receptacle is installed in; AND, it MUST be run as close as possible to the circuit conductors for that device. The length must be approximately equal to the circuit conductors, in order for the impedance to be as close as possible to that of the circuit conductors.

When you have no Equipment Grounding Conductor present in your premises wiring, the Code allows very few options for replacing a receptacle. The rules MUST be followed to keep the wiring as safe as possible. You can: 1) replace the receptacle with a listed 2-slot receptacle; 2) replace the receptacle with a GFCI type receptacle (and follow all of the rules above); 3) install a GFCI type breaker (and follow the rules listed above); or 4) install 3-slot receptacles with a new Equipment Grounding Conductor installed as described above. These are your ONLY LEGAL choices.

By the way, even though you most likely will not find any of these locations in your home, there are some instances where you are not allowed to install grounded circuits. (If you really want to know what circuits cannot be grounded, look in NEC (2005) Article 250.22.)

If any of the above information sounds confusing; I refer you to NEC 90.1 (C), and say "Hire a qualified, Licensed Electrical Contractor."

Answer 3

Yes you can install a GFCI receptacle on a circuit that has no ground wire.   This will provide you with some added safety over the old ungrounded two prong receptacles.  If you replace a receptacle with a GFCI all receptacles "downstream" in the circuit will also be protected.   In some areas the electrical code will allow you to do this in order to be able to use modern three-prong plugs without rewiring for a ground.  However, you will not get a true ground and will have to label the receptable with a "no equipment ground" sticker.   Having a true ground wire will only matter for certain electronics, and GFCI shouldn't be added to any circuits where you'll plug in medical equipment in case the circuit interrupts and shuts off the equipment.

Answer 4

Not really.  you can install it and it may work for a while however it will malfunction easily and if it trips you may not get it to reset.  Plus it will not give you a true Ground Fault.