Tips for pigtailing / wirenutting outlets with 12AWG wire

[JoeSpareBedroom]

Home Depot has allowed me to buy them on various occasions. But, they sort of stuffed them into the bag very quickly, as if they were selling alcohol to minors.

[Bud--]

In the case of a receptacle, a receptacle always has only one ground screw, so the ground is never wired through the receptacle. Detaching the ground wire from a receptacle will never interrupt the ground continuity. I see nothing that a green wirenut with a built-in pigtail adds to the ground continuity over a standard wirenut with a pigtail wire coming out of it.

Pigtailing out a ground wire with a standard wire nut also works for a fixture. If the fixture has its own ground wire it can be wirenutted to the pigtail ground wire.

The green wirenuts subract one from the number of wires spliced but have no other effect. Wiring can easily be done without using crimps.

bud--

[Bud--]

They do make bigger boxes.

If an electrician needs the space they will use a 4" x 4" x 2 1/8" box with a mud ring, or 4 11/16" x 4 11/16". It is possible to overfill these boxes, but you really have to try. Last I heard, these boxes could also be used by homeowners.

bud--

[kevharper]

I have the 22.5 cu. in. blue plastic boxes from Home Depot. The 18 cu. in. boxes are too small IMO but the 22.5's seem fine.

I don't think there there will be any problem stuffing the 22.5 cu.in. boxes with outlets and 12AWG wire/pigtails....

[gerry]

Clearly you have never used them and had such work inspected. Certainly the last outlet in a chain is an exception UNLESS it is something like a metallic box which needs grounding.

Pigtailing from the ground bundle with a standard wire nut does not meet code and won't pass inspection where NEC used. (most locations)

Chose to ignore the NEC code if you wish. The green nuts have a hole to extend one of the existing ground wires for use as a fixture ground. This forces the ground to be disconnected from the fixture, taking the green wire nut off doesn't help when servicing the fixture since it's still connected, not a pigtail.

You asked for the code citation, got it.

gerry

[Bud--]

Explain how removing a single wire from a receptacle ground connection screw will "interfere with or intrerrupt the ground continuity" of grounds to parts of the circuit downstream from the receptacle.

Clearly I have never used green wire nuts and have had my work inspected.

It will meet the code anywhere the NEC (not local opinion) is enforced.

A wire pigtailed out from a standard wirenut can be disconnected from the fixture in the same way. The code does not mandate that installations be idiot-proof.

Thanks for the cite.

bud--

>

[gerry]

Of course, use of proper materials and workmanship is up to local inspectors. In the three northeast states I have had work inspected in, all required grounding to be bonded via crimp or approved grounding devices at rough in inspection. The green nut is formally approved for such use. Grounding is inspected at rough in prior to adding fixtures. Maybe they are over strict or maybe they are just wise.

Let's consider the context of this thread. The original poster said he already had a pigtail wired to his outlets. I felt it worth pointing out he can not take off the device bonding grounds to attach the pigtail. All too often one ground does not get connected properly again with that approach. Everything works till someone is affected by ground fault with no effective safety ground.

I do not doubt some locals take a more relaxed view. Is it not wise to alert the original poster that special handling of grounds are required?

It really takes little effort to make it fairly fool proof. Why do less?

gerry

[kevharper]

I'm a little confused here.....

If you have three ground wire segments into a recepticle box (one pigtail attached to the outlet, one coming into the box and one exiting the box) and remove the pigtail from the outlet (where it's screwed to the outlet) to service it, how is the continuity of grounding for the rest of the circuit interrupted at all? Removing the pigtail from the outlet still allows the wires coming into and going out of the box to remain connected and thus maintain the continuity of grounding for the rest of the circuit.

[gerry]

The original poster pre-wired the pigtail to the outlet. The major issue is the grounds can not be disconnected to connect the pigtail.

There may be different interpretations in different areas. In the three states I am certain of, the ground continuity must be secured at rough in inspection with listed devices in a manner unlikely to be disconnected when a fixture is installed. In those areas, that usually means crimping or using an approved grounding wire nut, either way having a fixture.

Check out

as an example.

It is explicit that a listed means must be used. An ordinary wire nut is not mentioned (since it is not listed for such use). Crimp sleeves, listed clamps and green wire nuts are among those referenced for such use. "These connection devices are specifically listed for grounding terminations."

An image of such is on

No, if someone can find ordinary wire nuts listed for grounding, please post the reference.

One must keep in mind that the NEC always requires only listed materials be used.

gerry

[kevharper]

Sorry if I seem a little thick here. After all, I AM the original poster. :-)

Anyway, this is a new install of outlets on a circuit that currently is not powered.

If I have my outlets wired with three grounds going into a standard wire nut (one going to the outlet) I don't understand how replacing a bad outlet will interrupt the grounding of the rest of the circuit. If the ground wire is separated from the 'bad' outlet by loosening the screw on the outlet where the pigtail is attached. In this scenario, the wire nut with the three wires is never taken apart so continuity is maintained.

Am I correct on this? Maybe I just don't understand the issue fully. Also, I don't really understand how the green grounding wire nut improves the situation.

The one exception to this I can see is if I replace a standard outlet with a new one that has a pre-wired ground which can't be disconnected on the outlet side (like maybe a GFCI or something). In this case, you must go into the existing standard wire nut connection being used for grounding. I can see the potential for grounding interruption in this case.

Sorry for being a pain but I'd really appreciate some clairification.

[gerry]

Ok ;) What confused me is you already stated you have the jumpers on the outlets. Do you now intent to remove them first and properly bond the grounds at rough in?

You are correct, such will not interrupt the ground. But do check how the code is interpreted in your location. As you could see by the two articles I posted links to, special treatment of grounds is required in many locations by their interpretation of the NEC.

I could not find a single current reference to using conventional wire nuts in a search today. I am aware many inspectors differ, why blow a few cents and go a route listed as approved?

An approved green nut or crimp sleeve makes removing the ground bonding device pointless. Also, if so done and never touched, the original circuit's safety test of proper ground is pretty difficult to disturb. No temptation to take off the bonding device. It is a precaution enforced in many locals.

Why would a vendor even manufacture and pay to get a green nut listed if there was an "easy way out"?

Old work does not need to be retrofitted. However, with crimp or green nut, any fixture grounds can be connected to the permanent pigtail. Such only affects fixtures, not the rest of the circuit.

gerry

[Mark Lloyd]

Any why can't you turn off the breaker when replacing an outlet?

[Tom Horne, Electrician]

You are not being a pain. You are in fact correct that if the outlet, and were used the metal box, are connected to jumpers which are then spliced to the Equipment Grounding Conductors (EGCs); i.e. pigtailed; then no such hazard exist. The insistence on green wire nuts and crimp leaves on the part of some Authorities Having Jurisdiction (AHJ) is the result of a misapplication of language of section 250.4(C). That language requires that Grounding Electrode Conductors be installed without reversible splices. vis.

250.64 Grounding Electrode Conductor Installation. Grounding electrode conductors shall be installed as specified in 250.64(A) through (F). (C) Continuous. The grounding electrode conductor shall be installed in one continuous length without a splice or joint, unless spliced only by irreversible compression-type connectors listed for the purpose or by the exothermic welding process. What is missing from this position is a complete appreciation of the definition of a Grounding Conductor, Equipment verses that of a Grounding Electrode Conductor. Vis. Grounding Conductor, Equipment. The conductor used to connect the non?current-carrying metal parts of equipment, raceways, and other enclosures to the system grounded conductor, the grounding electrode conductor, or both, at the service equipment or at the source of a separately derived system. Grounding Electrode Conductor. The conductor used to connect the grounding electrode(s) to the equipment grounding conductor, to the grounded conductor, or to both, at the service, at each building or structure where supplied from a common service, or at the source of a separately derived system. This is one of the reasons that I support the proposal to change the term "Grounding Conductor, Equipment" to "Bonding Conductor, Equipment." The actual purpose of what we call the Equipment Grounding Conductor (EGC) is to bond all of the non current carrying metallic parts of the electric system to each other and, most importantly, to the grounded current carrying conductor so as to provide a low impedance pathway back to the source of the current in order to facilitate the operation of the faulted circuits Over Current Protective Device (OCPD); i.e. the fuse or circuit breaker. These conductors are installed on airplanes and on manufactured and stick built structures that are on ice. Neither of those can be effectively grounded but the careful installation of EGCs still provides the needed low impedance fault clearing path. What we are actually trying to accomplish is to bond everything that does not carry current together.

[Thomas D. Horne, FF EMT]

Greenies are a labor saving device rather than an answer to any real code requirement. By leaving the source circuits EGC longer than the others and splicing the longer one to the other EGCs with a greenie the labor used in making up jumpers is saved. The reason those wire nuts are listed for EGCs is that they are not suitable for splices in current carrying conductors and the separate listing makes that clear.

[gerry]

Your explanation of confusion with 250.64 can't be the case with green nuts, since they are reversible as are a number of other connection devices less commonly used but acceptable in such jurisdictions. The reason expressed in my local is strict interpretation that servicing a fixture should not _risk_ disrupting a circuit's safety ground continuity.

Certainly there is often a temptation to just take a wire nut off the grounds when working in a box. Often fixtures are replaced by untrained persons. Indeed, it sounded as if the poster that started this thread intended to disconnect the grounds to attach his pre wired ground already attached to an outlet. We need not go further than this thread to understand that such occurs.

It really doesn't matter if I agree or not with the inspector ;) In this case I do see a rational, some persons might take the easy way out and disconnect the grounds when servicing a fixture. Since they are not tested after rough in, often changed by untrained persons and failure to properly reconnect grounds could leave a serious safety hazard unseen.

What you cite below does not apply. It has a specific context of grounding equipment to service entrance. In the service entrance that earthing conductor is usually bonded via screws as are all branch safety grounds. Screws are very "reversible" None of the methods acceptable in

250.64 are commonly used in common home branch wiring even where strict interpretation of 250.148 as discussed before in this thread is applied.

I have not experienced ANY AHJ confusing 250.64 with stick use of

250.148 which is not to claim some have not. A branch circuit's safety ground almost always connects to the earthing conductor via a reversible set screw.

Whatever is "right" or "wrong", the original poster should consult his local authority for their interpretations.

gerry

[gerry]

I never found them labor saving and certainly not cost savings. If you strip one cable long enough for a pigtail, it is as easy to cut it and tuck it under a regular wire nut than carry yet another wire nut type around.

You will never find a green colored connector listed for current carrying use ;) Green has a very special meaning.

Since a safety ground must be rated to carry a branch circuits full current and as reliable as any current carrying device, it certainly is not an inherent limitation of the device.

In jurisdictions I am familiar with that require them or crimped grounds, the grounds must be bonded and pushed to the back of the box with a freely accessible pigtail(s) at rough in inspection. This is an attempt to insure the circuit's ground safety is not compromised at a later time.

gerry

[Member, Takoma Park Volunteer]

In the absence of a local amendment to the NEC it is an abuse of the AHJ's authority to require something that the code does not require. The purpose of a rough in inspection is to allow the AHJ to inspect what would not later be visible. That does not include anything inside the box. That is not to say that I think that pig tailing is a bad idea. I believe it is best practice. That being said the code is not best practice. The codes own language says it is what is necessary to achieve a reasonable level of safety from the hazards arising out of the use of electricity.

[gerry]

[original post is likely clipped to save bandwidth] On Fri, 02 Jun 2006 13:49:20 GMT, "Thomas D. Horne, FF EMT" wrote:

This may clarify the issue somewhat. Three things are important, NEC, UL and local jurisdiction. Regular wire nuts may or may not be UL listed for grounding. A listed device must be used. ANY jurisdiction is allowed to determine their code.

The link and quote below is from UL. About the only two things that are clear are the connector must be listed for grounding and a greenie will pass almost everywhere since it is explicitly listed for such use.

Good read at

( This is from the above mentioned Mike Holt newsletter - this is the UL response regarding 'green' wire nuts being required.

Answer 2: UL Response Mike ? I?d like to respond to your inquiry to UL regarding the use of twist-on type wire connectors for connecting equipment grounding conductors. I believe that to properly answer this inquiry we need to reference requirements in both the NEC and the guide information which UL provides for listed products. Sec. 250-8 of the NEC indicates that grounding conductors shall be connected by exothermic welding, listed pressure connectors, listed clamps, or other listed means. Pressure wire connectors are listed under the category of Wire Connectors and Soldering Lugs (UL Guide ZMVV). A ?twist-on? connector is a type of pressure cable connector that is tested to the UL Standard for Splicing Wire Connectors, UL486C. The requirements for these connectors include mechanical securement tests, as well as their ability to carry continuous current within acceptable temperature limits. Listed products in this category are identified by the words ?Wire Connector? (or abbreviation there of) near the UL Listing Mark which may be on the product or smallest unit container. Based on this information, a listed ?Wire Connector,? including the twist-on type, should be suitable for connecting equipment grounding conductors. There was also some question regarding the color of the connector insulation. Listed insulated twist-on type wire connectors are typically provided in a variety of insulation colors, however, to the best of our knowledge we have not listed a wire connector with green color insulation. NEC Sec. 250-119 requires covered or insulated equipment grounding conductors to have a green or green with yellow stripes outer finish, but there is no NEC requirement for the color of the insulation of a wire connector used to connect equipment grounding conductors. NEC Sec. 250-8 also permits ?other listed means? for connecting grounding conductors. UL has a category for Grounding and Bonding Equipment (UL Guide KDER). Grounding Connectors are a special type of connector that is tested to the UL467 Standard for Grounding and Bonding Equipment. The requirements for grounding connectors include mechanical securement tests, but unlike wire connectors, these connectors are not subjected to a continuous current test. In lieu of this test, there is a special short time current test in UL467 to show the ability of a grounding connector to safely conduct fault current. There are some listed twist-on type connectors with green color insulation that are listed as grounding connectors. Listed products in this category are identified by the words ?Grounding Connector? (or abbreviation there of) near the UL Listing Mark which may be on the product or smallest unit container. It should be noted that grounding connectors are only used for connecting grounding conductors, and unlike listed wire connectors, cannot be used to connect current carrying conductors (including grounded and ungrounded conductors). There are some listed Wire Connectors of the twist-on type that are also tested and complementary listed as Grounding Connectors, and the listing mark information for these products will identify them as both. The insulation on these connectors (with both listings) can be various colors, except green. We understand that some jurisdictional authorities may require listed grounding connectors for connecting equipment grounding conductors, and some may require only those with green insulation, and this is certainly permitted by Sec. 90-4 of the NEC. To satisfy this need, the listing categories of ?Grounding Connectors?, and ?Wire Connectors complementary listed as Grounding Connectors? were established for the manufacturers of these products. }

gerry

[gerry]

NEC is not law anyplace! Many local codes derive theirs (often verbatim) from NEC and many formally leave determination of workmanship to the appointed inspector. Even verbatim, NEC requires listed devices be used everywhere. That get's UL in the picture.

Bonding of grounds can not be examined once fixtures are in place. We have rough in and finish inspections. The only chance to view the ground bonding is at rough in.

gerry

[gerry]

Read NEC 90.4

gerry