Or left partially unscrewed? If you then place that current on the grounding conductor or ground wire you are making the ground system live. I would then send the two (hot/neutral knob and tube) on to the next outlet pair. How to use efficient index seek to find the latest row filtered on a small subset of rows? Yes, my understanding is that the code permits installation of a GFCI on an electrical circuit that has no ground. Family Handyman Fix old-house wiring problems. Of these boxes I checked, some are grounded via a connection to these twisted together ground wires, and some are not. @RobertLugg well, a wrong mental paradigm will definitely impede understanding. The NEC does not require you to add a ground but, that said, Both wires are same size and have identical covering on them. Secure the other end of the 8-inch grounding pigtail to the green grounding terminal on the three-prong or GFCI receptacle. Keep us posted. Watch out: if you are not trained in proper, code-legal, safe electrical wiring you should know that making a mistake can kill someone or set the building on fire. So why would you attach everything that is grounded - chassis of equipment, etc - to the unprotected neutral wire? Copyright 2023 This Old House Ventures, LLC. "The information in this guide is a summary of requirements Does the ratio of C in the atmosphere show that global warming is not due to fossil fuels? I think its a great idea, but of course I am biased and mostly uneducated. GFCI/AFCI breakers seem like a better solution to this one until you get to replacing the wiring. Still, a fake grounded box and receptacle can test as "wired correctly" using the circuit tester shown in your photo. There's also the possibility that there's a >20A breaker on it, which makes a regular receptacle illegal to put on this circuit: see Table 210.21(B)(3) for details. In a North American home, neutral has an equipotential bond to ground. [I add that if the existing two-wire circuit is a knob-and-tube installation, it is also forbidden to extend or add devices (such as more electrical receptacle outlets or lighting outlets) to that circuit.]. The connection is often unreliable. Bring old light fixtures wired with knob-and-tube wiring up to code by installing an electrical box in the plaster wall. "Evaluating Wiring in Older Minnesota Homes," Agricultural Extension Service, University of Minnesota, St. Paul, Minnesota 55108. You would either have to run a separate ground back to the electrical panel or to an approved local ground (uncommon) or you can install GFCI and it can protect the circuit but it can't be tested using the usual test methods. 0:00 / 6:56 How to Ground a Two-Prong Electrical Outlet | Ask This Old House This Old House 1.94M subscribers Subscribe 993K views 2 years ago Electrical Upgrades Ask This Old House. and AFCIs ARC FAULT CIRCUIT INTERRUPTERS for details about these devices. How to do molecular dynamics with different isotopes of the same element. It doesn't protect your electronic equipment from a power surge, though, because surge protectors work by shunting excess current through the ground wire to earth. K.B. Its connected to neutral at the box and runs "nowhere" electrically. next I went to the main breaker panel to see how that end of the circuits was and what I found was that the ground wire in each of these older cables (there are 4 or 5 of them total, leaving the breaker panel) are all actually 'grounded' to the cable connectors on the box, except for one of them, which is appropriately grounded to the ground bar in the breaker panel. On 2021-07-16 Luckily, metal boxes attached to armored, or BX, cablea type of wiring commonly found in old housesgenerally are grounded; the cables flexible metal jacket serves the same purpose as a dedicated ground wire. [Click to enlarge any image] Instead you'll want to run a new circuit to that area - a desirable improvement both to avoid overloading an older circuit and also to provide electrical grounding required for many modern appliances. Where attachment to an equipment grounding conductor does not The wiring show below is improper and unsafe and is an example of why the BX cable covering is not a true electrical ground. Now an equipment grounding conductor that is part of another branch circuit that originates in the same panelboard as the branch circuit for the receptacle can be used to provide a grounding means for the replacement receptacle. It must be connected to this terminal, not to the LOAD terminal or the GFCI won't offer any protection. Which due to a wire break is now floating at 120V. Follow the steps below to learn how to ground an outlet. 4-77 1977 [Lots of sketches of older-type service panels.]. Apologies for the delay. If your house wiring predates the adoption of this requirement, you don't have to replace your ungrounded receptacles with grounded ones. When replacing your two-prong outlet with a GFCI, an electrician starts by turning off the breaker controlling the outlet circuit and unscrewing the outlet from the electrical box. (C) Nongrounding Receptacle Replacement or Branch Circuit Extensions. By submitting your email, you agree to our, Cost: $20 for a GFCI and $200 for professional installation, 13 DIY Backyard Games and Play Structures, The 5 Best Inverter Generators (2023 Review), Generator Buying Guide: What You Need to Know (2023), 7 Electrical Safety Tips for Holiday Lights, Do Not Sell or Share My Personal Information. Replace a nongrounding-type receptacle with a grounding-type if there is an equipment grounding conductor available and connect the grounding conductor. Under normal operating circumstances, the electric devices in a home should work without issue. Or can the multiple outlets be branched off a main feeder wire back to the breaker box ground bar? Stack Exchange network consists of 181 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers. - Thanks. Rewire outlet circuit: Location of outlets, wire run alternatives, GFCI best practice, and outlet spacing, Old house, 2 prong outlets - safety question for kids. 3. The rest of the procedure is as follows: You can wire a three-prong outlet to the GFCI by connecting it to the LOAD terminals. In other words the incoming neutral is connected to one terminal and the outgoing neutral is connected to a second screw that is electrically common with the first. If the ground becomes energized, the grind and shielding become parallel paths for current, although not necessarily identical current levels. Equipment grounding conductors can be installed outside of a raceway or cable assembly for certain existing installations. It does not matter which wires you attach first, but it is not a bad idea to start with the ground wire. The old outlet has 2 neutrals, 2 hots and ground. Browse other questions tagged, Start here for a quick overview of the site, Detailed answers to any questions you might have, Discuss the workings and policies of this site. On 2021-08-11 You would either have to run a separate ground back to the electrical panel or to an approved local ground (uncommon) or you can install GFCI and it can protect the circuit but it can't be tested using the GFCI usual test methods. Where do I attach the fixture grounding wire when no supply grounding wire is provided? I'm unclear on the exact formulation of the question here Randy.Yes one could add a separate ground wire from an electrical receptacle box to the main panel, properly sized, routed, protected, in order to add a ground at that location and thus to permit change-over from a two-prong electrical receptacle to a three prong one that includes the ground plug opening.IF that were done a circuit test would show proper wiring.Watch out: if you simply connected a metal electrical box to a local ground such as a grounding electrode or water pipe and then installed what I consider a "fake" grounded 3-prong electrical receptacle and wired that receptacle's grounding screw to the metal box that would be unsafe and improper - the metal box body, while it should be connected to a grounding conductor, is not intended to serve as the grounding pathway and in various situations is dangerous. It may not be obvious to a normal person who's not an electrician, but the neutral wire in an electrical circuit carries current. We don't know that the plumbing doesn't follow around through a dielectric fitting or through some plastic piping nor do we know that the piping extends far enough under ground to form an electrical ground itself. How to get mempool tx ordered by sat/vbyte, create letter charts with pictures for children - for alphabet learning. "Home Wiring Inspection," Roswell W. Ard, Rodale's New Shelter, July/August, 1985 p. 35-40. Luckily, metal boxes attached to armored, or BX, cablea type of wiring commonly found in old housesgenerally are grounded; the cable's flexible metal jacket serves the same purpose as a dedicated ground wire. Loose connections, worn insulation, and broken internal parts made it easy to get shocks. Replacing an ungrounded outlet with a ground fault current interrupting (GFCI) receptacle protects you from shocks, but it won't protect your electronic equipment from power surges. Learn more about Stack Overflow the company, and our products. An equipment grounding conductor shall not be connected between the grounding type receptacles. Only one image can be added per comment but you can post as many comments, and therefore images, as you like. The equipment grounding conductor of a grounding-type receptacle or a branch-circuit extension shall be permitted to be connected to any of the following: (1) Any accessible point on the grounding electrode system as described in 250.50, (2) Any accessible point on the grounding electrode conductor, (3) The equipment grounding terminal bar within the enclosure where the branch circuit for the receptacle or branch circuit originates, (4) To an equipment grounding conductor that is part of another branch circuit that originates from the enclosure where the branch circuit for the receptacle or branch circuit originates. Watch out: do not ignore the NEC requirements (NEC Section 210-7) to LABEL the GFCI receptacle on a two-wire (un-grounded) circuit as, "GFCI Protected" and "No Equipment Ground.". The hot and neutral wires must be connected to the proper terminalson the electrical receptacle. Your electrician could label each orange wire in each box using green tape to show its a grounding conductor. However, if hot happened to hit the ground of the device, current would flow through the bypass, and the GFCI would detect that delta in-out current and throw. Readers have proposed jumping the neutral to ground, for example. . What Is a Ground Wire and Why Is It Important? by inspectapedia.com.moderator (mod) - causes of low voltage at an electrical receptacle ("outlet"). ok, so here is the idea. Because some devices can be damaged if older style cord plugs are reversed on an un-grounded circuit and because some devices may depend on electrical grounding for safety, in my OPINION a better approach would be to put a GFCI breaker in the panel serving the circuit and to use only 2-prong electrical outlets on a two-wire circuit. Thanks much. receptacle(s). Ok, this is going to be hard to hear, but you need to hear it: you need to remove and replace all your knob and tube wiring. Loosen the wires on the hot and neutral sides of the outlet. In summary, your plan would be IDENTICAL to jumping the line neutral terminal on the GFCI to the ground terminal. An electrical receptacle cover plate must be installed over the finished receptacle. And you'll notice that some, especially older wall lamps don't even use a polarized plug. through a ground-fault circuit interrupter. Advice? Your tester may not indicate a problem but that's because it's not as smart as a GFCI, AFCI, or your local electrician. Where would I tie the ground wire into when it reaches the existing fixture? Can you convert a double outlet into single. "Basic Housing Inspection," US DHEW, S352.75 U48, p.144, out of print, but is available in most state libraries. Rinse and repeat for the other outletsthey all get the pair. If the GFCI is too big, youll need to purchase and install a larger box. Two problems make the safety of these approaches questionable. Its design suggests that a ground is present when one is not: a condition that is innately risky since some appliances require a ground for safe operation. Same old story, right? 3. a receptacle wired on a circuit that uses a shared neutral wire (also a damaged neutral) If you are not trained in proper, safe electrical wiring it's best to hire someone who has that expertise. Here's how to do it without breaking the plaster and lath. This was broadly legalized in the 2014 NEC. The box and BX cable I was working on became "live" (and shocking) when she turned on the vacuum cleaner! That general remark means the on-site electrician decides where and how to run the wire, but when workmanship is proper, along with. (c) A nongrounding-type receptacle(s) shall be permitted to be replaced with a grounding-type receptacle(s) where supplied But the ground pathway back to the panel in that case is unsafe and unreliable for at least these reasons: 1. Share Improve this question Follow edited Apr 1, 2016 at 11:11 ArchonOSX 19.6k 3 28 49 asked Feb 23, 2015 at 23:58 wayne 31 1 1 2 In general the black and red are going to both be hot, and you shouldn't attach the bare ground wire to the white neutral. He thought that BX or armored cable was providing the ground - it's not, and trying that method is also unsafe. Note: appearance of your Comment below may be delayed: if your comment contains an image, photograph, web link, or text that looks to the software as if it might be a web link, your posting will appear after it has been approved by a moderator. Disconnect the neutral wire, which is white, and connect it to the chrome LINE terminal. i had planned on attaching wire to the box but after reading see we cannot rely on the BX to maintain ground and could cause an unsafe shock situation. Upon removal of old unit, I have only 2 wires in ceiling. We need to research the code details further about inconsistent system grounding; an example that comes to mind is the code requirement that a separate branch panel in a detached garage is often connected both to a local grounding electrode at the garage and back to the system ground bus (and through it to the main building grounding electrode) back in the main panel. As for your alternate idea, plenty said already about what a bad idea that is. If your electrical cables have metal sheathing that runs all the way to the panel, the sheathing can serve as a ground path. Take a look at that article and let us know if questions remain. The sheathing or wire gets energized in the event of a short circuit, potentially overheating and causing a fire or giving someone a shock. In fact, those "neutral" wires always have a small amount of resistance and a small voltage when under load, and anyone who touches that circuit path becomes a parallel load under the right circumstances. Really, jumping live to neutral to convert a 2-prong outlet to 3-prong is just not at all a good idea. However there are some concerns worth thinking about: 1. you cannot use the normal test buttons on a GFCI that depend on making an internal short to ground - as there's no groundAlso see AFCI GFCI WIRING, TESTING & SAFETY. We describe how to add a grounding conductor on older two-wire circuits that lacked an original grounding conductor, citing pertinent sections of the U.S. National Electrical code such as NEC Article 250.130 Equipment Grounding Conductor Connections. My question may be ridiculous but what if I add a compasator to the ground screw to absorb a short? Because neutral is the normal current carrying conductor (unlike ground), and so it has current on it routinely. (Aug 3, 2014) JR said:I believe that the NEC (at least at one time in the past if not currently) allows replacing a 2-wire ungrounded receptacle with a 3-prong GFCI receptacle and leaving it ungrounded. The dangers of using the existing metal box and BX or armored cable for the ground path (I know that it's tempting) are several: That path, which relies on numerous parts that can often be loose, is unreliable: the path is from the new grounded receptacle's internal grounding connector through a rivet to a metal strap on the body of the receptacle, through mounting screws through the receptacle's mounting ears, through a threaded hole in the metal receptacle box, through a metal BX connector which itself relies on at least four parts to be secured to the metal box, through a set screw from that connector into the armored cable, and thorugh god knows how many more sets of these parts down the entire remainder of the electrical circuit. (Apr 24, 2016) Anonymous said:.i have a blue and white wire is the .blue negative? But an ungrounded GFCI cant safeguard sensitive electronics, such as a computer or phone, from the interference caused by stray currents. The metal jacket of this type of electrical cable is not itself a safe nor reliable electrical ground. An electrician or EE using a DMM or VOM can determine which is the current carrying wire. An electrician using a DMM or VOM would check each wire to identify which was the hot and which the neutral wire. The second method is actually dangerous. So can I extend the black and white from the existing 2-wire receptacle to new location and install a 2-wire outlet or GFCI outlet but leave the romex ground not connected at each end? The National Electric Code requires that all receptacles installed in all 15- and 20-amp, 120-volt circuits be grounded. I ran the wire to the existing exterior light fixture through the wall and to the inside of the porch's dormer roof.It seems that exterior lights have the requirement of being GFCI protected, however, the existing light fixture that I'm trying to pigtail off of is a two-wire system. It seems that exterior lights have the requirement of being GFCI protected, however, the existing light fixture that I'm trying to pigtail off of is a two-wire system. John Cranor [Website: /www.house-whisperer.com ] is an ASHI member and a home inspector (The House Whisperer) is located in Glen Allen, VA 23060. How do I do this, and what do I do with the green neutral wire. Making statements based on opinion; back them up with references or personal experience. As far as K&T safety - not. Where is the supply coming from and what is on the other end? We appreciate your taking the time to write. Equipment grounding jumpers can be located outside of a flexible raceway if the bonding jumper is installed in accordance with 250.102(E). But remember that the typical wiring instructions for receptacles include a ground wire that may not be present on your circuit - as we explained just above. See details in, Beginning in 2002 the NEC also required arc fault protection for electrical outlets for bedrooms. Or does it matter? Thank you again. Don't ground to the electrical box. Try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly. @Don Mims, you can't count on a reliable electrical ground from an arbitrary connection to a plumbing pipe in the building.