What you describe is permitted but the connection must be within the first 5 feet of the metal water pipe where it enters the house. I'd be suspicious of the few receptacles that do have the third prong until they have been verified to be grounded in a code compliant manner. Long, long ago in a galaxy far, far away, some of us were working on FAQ's and some were posted and can be accessed from the main page of the electrical wiring forum. The following is one that deals with this subject. It has not been proof read by other electricians and I invite them to submit comments or changes. Maybe we'll get this posted since this question comes up frequently. One problem frequently encountered in an older home is what to do about replacing a 2 prong ungrounded receptacle. There are several options of varying complexity. If an equipment ground is available in the box, then the receptacle must be replaced with a grounding type receptacle. See notes below on how to determine if there is an equipment ground available in the box. If there is no equipment ground available in the outlet box,you can replace the receptacle with another 2 prong receptacle. This is a reasonable course of action if you do not need to plug in any load that needs to be grounded. 2005 NEC 406.3(D)(3)(a) See notes below for a list of equipment that is required to be grounded. Another option that can be used, if no equipment ground is present and you do not have equipment that is required to be grounded, is to use a ground-fault interrupter type of receptacle. You must attach a label to the receptacle that states "No Equipment Ground." It is also possible that you could use this GFI receptacle to protect receptacles downstream and this would allow the replacement of those receptacles to be the 3 prong grounded type. You must label these receptacles "GFI protected, no equipment ground." 2005 NEC 406.3(D)(3)(b) and 406.3(D)(3)(c) The most complex option is to install an equipment grounding conductor. You must attach this conductor to the box if it is metal. The other end of this conductor can be connected to one of the following places: 1. Any accessible point on the grounding electrode system as described in 250,50 of the 2005 NEC 2. Any accessible point on the grounding electrode conductor 3. The equipment grounding terminal bar in the enclosure that the circuit originates 4. For grounded systems, the grounded service conductor (neutral for a dwelling service) within the service equipment enclosure 5. For grounded systems, the grounding terminal bar within the service equipment enclosure. 2005 NEC 250.130(C) Strict interpretation of 250.130(C) would require an individual equipment ground being run to every receptacle you plan to replace. There is no provision for connecting to another equipment ground when you are replacing receptacles. Installing an equipment ground as stated above can be a considerable amount of work. For very little extra effort, you could run a new circuit to the location that needs a grounded receptacle. Notes: 1. If the receptacle box is fed with metal conduit, then it is likely that the box is properly grounded. To verify this, connect a test light or voltmeter to the hot wire and the box. You should read 120 volts (more or less) on the meter. If youre using a test light, it should illuminate as brightly as it would if connected hot to neutral. 2. Your box may be fed with Armored Cable, which is still referred to generically as "BX" in some parts of the country. The old BX, even though it has a steel jacket, is not a suitable equipment ground and using it as such is a fire hazard. The newer Armored Cable is a suitable equipment ground. To determine what you have, you must pull a cable out of its connector, possibly remove the red anti-short bushing and look for a real thin strip (about 1/16") of aluminum run inside the armor with the conductors. If this strip is present, you have the newer type AC cable and can consider it to be grounded. You can perform the test in note 1 to be sure. 3. If you find any bare or green wires in the box, they may be an equipment ground. These wires should be tested to verify that they actually are equipment grounds. 4. The following cord and plug connected equipment is required to be grounded (2005 NEC 250.114(3)), unless protected by a system of double insulation: A. Refrigerators, freezers, air-conditioners. B. Clothes-washing, clothes drying, dishwashing machines; kitchen waste disposers; information technology equipment (your computer); sump pumps and electrical aquarium equipment C. Hand-held motor-operated tools, stationary and fixed motor-operated tools, light industrial motor-operated tools D. Motor-operated appliances of the following types: hedge clippers, lawn mowers, snow blowers, and wet scrubbers. E. Portable handlamps.

I stand by my statement. You might read the current information etc. You are correct they are bonded together at only one place in an instillation; some locations now require that they are not. You are also required to have separate bars for the neutral and safety ground, if they are the same why? Why do they only want a single point ground? The earth is the ground and the reference point and hence the term ground. Why do you think the 25 ohm or less ground rod resistance to earth requirement exists? I know of farmers that ran a single wire to an outbuilding and drove a ground rod for the other to save money and the lights worked just fine. Your assumption of a ground fault does not compute. You describe a phase to neutral fault not a ground fault. Remove the bonding screw and connect a breaker to the safety ground then you have a ground fault and if the system is correct the breaker will trip. To make it easy just connect a test light between them, if it does not light you have a problem. Whenever a current flows through a conductor there is a voltage drop, ohms law defines this. You do not want that drop in the ground circuit. The difference can do interesting things if you get between them. Do you want to sit on the ground and when you turn on the power tool gives you a zap? The neutral carries only the difference current between the phases, the ground caries none. I assume you have four wires in your box, two phases (black and/or red), one neutral (white or bare) and one ground (green or bare separate from the neutral). All branch panels are connected with four wires, 220 assumed, one neutral, two phases and one ground. The normal transformer that feeds a house has a center taped winding with the center tap connected to the ground and called the neutral. If the neutral fails the safety ground will carry the current and protect your system that is why they upped the wire size requirement for the ground many years ago. Then you could get 12X2 with a smaller gauge ground #16 I think). The Edison transformer is also grounded via a ground rod on both the primary and secondary sides. I know this first hand, I have a neighbor with an open neutral and his ground current is coming in my city water pipe as well as the neighbors. I see 10 Â 30 amps on the water and gas pipes, even with my Edison power disconnected. Edison says this is normal and cannot do anything about it. They also told me it is very common in older subs and was caused by open neutrals.. The equation is resolved with the addition of a CFGI breaker, if the neutral opens it will trip if there is any connection to the earth. AFCIs take care of the arcing fault problems. CH makes a combo that costs about the same as the AFCI. I have a transfer panel out side and that is where they are bonded together as code requires. Four conductors connect each panel and sub panel. There is no bonding screw in any of the panels inside. The inspector did check this. You are correct in the normal flow of current. GFCI breakers measure the current in both wires, if they are more then about five mA different it trips. Where do you suppose the current is flowing?

The reason an outlet has three prongs is that the 3rd prong accommodates a ground wire. If you don't have a ground wire running to each receptacle box, your new 3-prong outlets are really just 2-prong outlets because the grounding prong is not connected to anything. Further, ungrounded 3-prong outlets give the false impression to people that the circuit is ground-protected, when it's not, and that is not safe thing to do. The difficulty of getting ground wires from the main panel to each receptacle will depend entirely on the construction of the house and how easy it is to snake wires to each box. Given your limited knowledge of wiring, this is a job to be tackled by an electrician, or with the help of a knowledgeable friend.

> Residential premises where the electrical system is in good condition > and complies with the code in effect at the time it was constructed > are not required by the NEC to make any changes simply because > the NEC is revised. Nobody said NEC changes required wiring changes. Nothing posted justified that conclusion. Had all two prong receptacles been left unchanged, then wiring was perfectly safe. Problem is that someone threatened human life by installing three prong receptacles on a two wire circuit. And connected its safety ground prong to the neutral wire. That is two serious safety violations of the NEC. If three prong receptacles are used, then interior cables must be upgraded to three wire OR that GFCI recommendation (with labels) is required. No way around those rules that completely apply once a three prong receptacle replaces a two prong.