Wiring ground on new outlet question

[Phil Thien]

I'm cutting a piece of 12-gauge Romex that has some extra slack in it, and I'm inserting a box with two receptacles (so I guess electricians call that a double duplex).

I was and found this (http://www.wikihow.com/Install-an-El...t-from-Scratch step #9):

Connect the ground wire. If a metal box, cut (2) eight inch lengths of bare copper wire, and combine them and the bare wire from the romex cable under a properly sized wirenut. The free end of one wire will connect to the green ground screw of the outlet, and the other free end is to be connected to the metal box with a green screw (expressly for that purpose) or other approved means (special clips, etc). If a plastic (or other non-conductive material) box is used, simply connect the bare copper wire directly under the green screw of the outlet

I'm using a metal box and a metal cover, with metal screws connecting the two.

Do I really have to wire a ground to the receptacle, and another ground to the metal box? Or would it be sufficient to wire the two grounds to the box and let the metal screws carry the ground to the receptacles?

My layman thinking is that the screws would be sufficient for the ground. But I may be overlooking a scenario in which they wouldn't, and I want to get it right.

But if conduit can serve as a ground, why can't my all metal box (box and cover that holds the receptacles) do the same thing?

The only answer I can think of is that if someone unscrews the cover and pulls it away from the box, they have broken the ground. But if they are pulling the cover off with the circuit live, the ground may not save them anyhow.

What should I do?

[Foras Noir]

This is a "hot button" issue with inspectors. Follow the local code - not something from the internet.

It is essential that the mechanical system (pipe, emt, boxes, etc.) have a continuous grounding conduction path. You don't want a dead short against the mechanical system to be conducted to ground through a device (the plug set or whatever). That device could be common with a Human. Seriously, this is a real issue and no one messes around. Dead shorts on the mechanical system are more common than anything else - save maybe internal motor shorts.

But the better question is why taunt these guys over something so easy to do? It takes less than a minute to do it right.

If you are going to do unpermitted work, at least follow the rules. You are more likely to get a break when you get caught.

[Phil Thien]

But the better question is why taunt these guys over something so easy to do? It takes less than a minute to do it right.

I guess my hang-up is that conduit is commonly used to carry the ground. So I didn't understand the distinction between using the conduit, and having an all-metal box.

So you're saying the ground wire to the receptacle is required? And if there are two receptacles on a metal cover, they each get a ground wire?

[Aaron Wingert]

The box must be bonded and the receptacle must be grounded. No way around bonding that box when you're using metal boxes, and there's never an instance where you don't physically connect the equipment ground to the ground terminal on a receptacle. Yes, the connection of the grounded receptacle to the metallic box pretty much effectively bonds the box to the grounding system, but the code is about safety and therefore you must do both. As you probably know, only one box must be tied to the ground in a metallic conduit since the conduit provides an effective ground path.

It is much too easy to do this to even think about not doing it.

Your logic holds water when talking about switches. A switch in a metal box does not have to be grounded. However, the metal box must be bonded to the grounding system. When you use a plastic box the switch itself must be tied to the equipment ground due to the potential hazard of the metallic faceplate screws or the installation of a metal faceplate. No, plastic faceplates and plastic faceplate screws do not negate the code requirement.

Permit or not, take pride in your work and do it right. Knowing that you did the job in a way that cannot be scrutinized by a professional in the future when you sell is a good thing. So is the safety level achieved by properly grounding the system the way the code requires. Remember, the code is a minimum standard...It isn't a prescriptive method for how to do the very best work possible. It is purely about life safety.

Yes, I'm a building inspector.

[Aaron Wingert]

So you're saying the ground wire to the receptacle is required? And if there are two receptacles on a metal cover, they each get a ground wire?

Yes, you must pigtail to each receptacle. Whether there is one or twenty!

[Adam Strong]

The whole idea of "getting caught" is a rare instance. So long as the job is done correctly, no one will get in trouble for anything... No one knows how many outlets are in the house, most permits on file don't even include this info. I got an elec. permit to install a sub panel in my detached shop and included the # of outlets on the application. The officer signing the permit crossed it out and did not include it on the printed form and no inspection was required. The biggest risk you run is that if it is done improperly and causes a fire, your insurance will find out it was due to improper wiring and possibly deny the claim. - Or - If a home inspector happens to check the outlet you installed when selling your home, you will then have to correct the problem for the buyers. Best to do it right once, than have to go back and re-do.

Bottom Line: Find out what your local code requires, follow it to the letter, and live worry free.
Good Luck Phil

[Aaron Wingert]

Rest assured that permits are in fact required by the NEC and the ICC model codes for work such as installation of new receptacles, new lights, new wiring, or even new devices on existing circuits. And for good reason guys.....I've made a career out of inspecting such projects, and many many many professionals can't or won't do it correctly. DIYers make mistakes and don't realize it. Permits are cheap in most cases and may not be required for this type of work in some jurisdictions based on local rules. But trust me, getting caught doing the work without a permit does happen and it can get very expensive in some areas. I run into it on a regular basis and where I work it is incredibly expensive to get caught without a permit when one is required.

[Bill Brady]

There is a provision in the new code if the paper that holds the screw is taken out you dont have to use a seperate ground. The instructors at the last code seminar I went to were a little confused by the way it is put in the code. The problem is most places dont use the latest code either.

[Phil Thien]

After all this screwing around with the notion of "cutting-in" an outlet, I looked up in my ceiling just ten minutes ago and realized that if I turn one 4' fixture around and plug it into a different outlet (previous homeowner put outlets up in ceiling to plug figures into), I can free up an outlet and my problem is solved.

Which is good, because the line I was going to cut into is 12-gauge. And quite frankly, wrestling that much 12-gauge into a box wasn't gonna be the highlight of my Sunday.

Seriously, you have to have fingers of steel to wire nut that stuff.

Thanks for the help anyway. I learned quite a bit. And identified a shortcoming in another area (electrical) that I need to address.

[Phil Thien]

There is a provision in the new code if the paper that holds the screw is taken out you dont have to use a seperate ground. The instructors at the last code seminar I went to were a little confused by the way it is put in the code. The problem is most places dont use the latest code either.

Amazing.

So that brings up an interesting question.

For a smaller municipality like mine, do they have a code that I can get a copy of? Or is the code whatever the inspector decides it to be?

Do they work off national code and adopt the "newer" code every so often? Would a community of 15k people actually have their own code?

[Jim O'Dell]

From what I've read, most towns will adopt a basic set of codes. Possibly changing, adding to, or taking away certain lines. Probably very little of the latter. I would guess that the smaller the town, the less is changed, just because they don't have the money to have someone on staff that knows enough to know what to do. If they have a paid fire department, they might be lucky enough to have Chief that has seen something from his experience that he wants done. Can anyone confirm these situations?
Don't know if cities have copies of the code that you can get. I'm sure they have one you could look at. Possibly a copy at the Library? It has to be written somewhere for them to adopt and follow. Jim.

[Aaron Wingert]

Yes, your city will have a copy of the code for your review at their office. The code requires that at least one copy of every adopted code is available for public use/viewing during business hours. That includes the building code, residential code, fuel gas code, electrical code, plumbing, HVAC, property maintenance code, etc.....

Libraries should have it as well, but won't know what the local cities have adopted. So be sure to check first!

Modifications to the adopted codes are located in the city's code of ordinances in the section that covers building and code adoption. Your best bet on that is to ask an inspector if there are any unique facets to that particular city's code adoption. You'll rarely see cities modifying the code in the areas of grounding, bonding, or basic electrical. Usually the adoption modifications are more likely to deal with zoning, setbacks, square footage, and issues such as egress, etc.

Jim's right regarding smaller cities to some degree, but that's not always the case either. Many small cities do have very effective building/inspection departments, and some do have the fire department do their inspections. Just depends on the town.

As an inspector my best advice to you is to call or stop by city hall and chat with an inspector. Most are usually happy to help if you're being proactive and you haven't just got caught doing something wrong. Some are jerks but most are a wealth of information and just want to see your work done correctly and safely.

[Callan Campbell]

After all this screwing around with the notion of "cutting-in" an outlet, I looked up in my ceiling just ten minutes ago and realized that if I turn one 4' fixture around and plug it into a different outlet (previous homeowner put outlets up in ceiling to plug figures into), I can free up an outlet and my problem is solved.

Which is good, because the line I was going to cut into is 12-gauge. And quite frankly, wrestling that much 12-gauge into a box wasn't gonna be the highlight of my Sunday.

Seriously, you have to have fingers of steel to wire nut that stuff.

Thanks for the help anyway. I learned quite a bit. And identified a shortcoming in another area (electrical) that I need to address.

Please FOLLOW the Building Inspectors advice about never short cutting a ground. The only machine short- to -ground I've ever had the "pleasure" of encountering was on a 220 volt stick rod welder, it threw me a few feet back and left the impression that you NEVER want to feel that much voltage going through you again! Counting on a metal to metal contact with metal conduit and boxes means that the person never allows for the loosening of those connections, or rust/corrosion ruining them for a ground path. I've seen both happen all my life, esp with outside power installations.
Having said THAT, take this to heart, I recently had to uninstall our roof-mounted A/C compressor to allow the roofers who were doing a complete tear-off to move the unit around as they need to.
Much to my surprise, I discovered during the process ,that either the electricians who installed our new 200 amp services, or the HVAC guys who installed both A/C systems[ sep. 1st and 2nd floor units] and a new boiler ran the 220 line to the roof with NO neutral, NO ground, and piggy-backed the air handler unit onto the compressor wiring, leaving some wiring for that seperate blower motor taped up at a nearby junction box mounted on our chimmey. That means they actually ran it from a breaker in the panel, to the roof, but NOT out of that junction box and over to the disconnect switch for the A/C. For 10 yrs our house has had a "rigged" electrical circuit that I didn't know about.
Since they were ALL working on the house at the same time in 2000, I'm not sure who actually ran the circuit up to the roof. I'm HOPING it was the HVAC guys cause having regular electricians doing something this poor and unsafe in work practices is more scary to me than having had the HVAC company do this. After all, they replaced both old 100 amp services[it's a 2 flat, with sep. panels for each floor], so what else is lurking with all the work being done.
Run your ground wires, keep it safe. Meanwhile, I will probably have to run 3/4" conduit from the basement to replace the undersized 1/2" conduit since with ALL the correct wires running my A/C circuits, 1/2" is probably too small by code and commen sense to handle my "missing" wires for the 220 circuit, and those "unused" blower motor/air handler wires for that circuit.

[Dave Hartunian]

For those of us that have a little doubt in their ability to hookup wiring I ran the wire from each outlet thru the joists, and left plenty of extra wire at the panel. I payed a local Licensed electrician who was slow with work and payed him 100. to connect and check everything out. Worked out great.

[Phil Thien]

Well, seeing as this thread was resurrected, I will post a follow-up.

The outlet box that was lose was screwed-in to replace the nails (could have moved it and renailed, but I was able to screw it more easily since the box is wired).

BUT, I noticed when I opened the box to screw it down that they (original installer) took the bonding wire inside the armored cable (my basement was wired with armored cable) and wired that to the ground screw on the receptacle. It looked funny.

So I did some research and decided to add a proper grounding strap between the receptacles and the boxes.

Good enough till I re-wire the shop.