Wiring Question
 

I just installed a new, 3-prong outlet. The problem is, there was NO ground wire. It's old wiring and the original outlet was an odd 2-prong with no place for a ground wire. Those lines have been fine since we've been here, about 23 years. Is it safe to have it like that? I needed to change it to plug a fridge into, and didn't want to use an adapter.

If the fridge has a three prong grounded plug, it isn't as safe as it should be. I would be thinking about pulling a new grounded wire from the breaker or fuse box or at least "cheating" in a ground wire to the nearest grounded circuit. The "cheater" wire certainly wouldn't meet any kind of electrical code, but it would meet my personal safety requirements.
Tom

you are better off running a dedicated circuit for the fridge with new wire, complete with ground. Code calls for a dedicated circuit in new construction anyway, since there is quite a surge when the compressor initially fires up.

What type of wire runs to this outlet? Is it metal casing wire or plastic casing?

Cloth covered 2 strand is the wiring. This isn't new construction, I'm working with old, existing wiring. I don't have the knowledge or skill to run a new line.
The "box" contains push-button breakers. No idea how to shut off all power to work in there.

There is a separate box for a heavy duty outlet that ran an arc welder, but I have no idea if it can be converted, or how.

In many cases the metalic box in the wall will be connected to ground and the outlet will pick up its ground through the screws that hold it in the box. The small plug in circuit testers will tell you if you have a ground or not.

IMO, the new plug is no more unsafe than the old one.

As an owner of a very old house, there is always a trade off between "up to code" and the time and expense of rewiring.

As another poster stated, it's not as safe as a the 3 wire line, but it is not inherently dangerous, either, IMO.

Is should be corrected, but it would not keep me up at night worrying, unitl then. If that was case, I would not get a wink's sleep, in this old farmhouse. ;)

.....................go to home depot and purchase a "how too" book on home wiring ! It's not rocket science , for 120 volt ac voltage you've only got 3 wires . One hot wire , a ground and a neutral . Take a pic of your fuse panel with the door open and post it on here ! Then remove the front panel with the screws and take a pic of that . Removing the screws won't shock you , just don't touch any of the terminals . The theory will become clear too you once you understand the basic schematic of how the panel was wired . You can fully analyze the connection(s) without touching or disconnecting any wires . The more you know and understand about how your home is wired the easier it will become too fix the problems and save yourself tons of $$ . , fordy:)

Here is the main panel...
http://i215.photobucket.com/albums/c...Wiring009a.jpg

Here is the separate box for the arc welder plug...
http://i215.photobucket.com/albums/c...Wiring006a.jpg

The outlet box is not grounded. The original outlet had no place for a ground, and the lines in and out are 2 strand. No ground wire at all.

I'm going to unplug a chest freezer from an outlet I know is grounded (I installed it recently) and move the fridge so I can plug it in there. The chest freezer isn't holding much, so I can just put those things in the freezer of the fridge. I just don't trust that 2 strand for a fridge.

................Purchase a ground rod (8 feet long) , install two of the clamps with set screws and tighten down at about 7 feet as once you start driving the rod the top will flaten out and become too round to allow the clams to slide over the top . Drive the rod with a small sledge while standing on a 6 foot ladder , use short strokes so you don't bend the rod , drive as deep as possible ! Purchase enough #6 solid copper wire too reach from the panel to the rod outside , there should be a big connection lug to slide the #6 wire into on the inside of the service panel . Now , you've got a fully grounded panel . The welder panel will also be grounded back thru this panel as well , assuming it is connected correctly . , fordy

..............Note , IF your panel isn't grounded , the only "REAL" ground you have is the one at the power pole where the stepdown transformer is located . UNless , you have a ground on the service drop prior too entering your home . You really need to install a ground for the service panel inside your home . , fordy

In direct answer to your question, the socket will be "pretty safe" but not completely safe provided you go the polarity correct and your ground is good. Here is why:

Quickly described, your power is supplied by a big transformer on the power pole. The transformer output has a long coil of wire that develops a lot of voltage at each end, and has minimal voltage in the center. (It is a lot more complicated than that, but that is the basic idea) The black or hot side of your socket goes through the breaker, which connects to one of two hot busses. Those are connected to the two ends of that wire coil in the transformer (lots of voltage there, remember?). The white or neutral side goes to a buss that is physically connected to a ground and the center tap of that coil of wire in the transformer (next to no voltage there). The ground wire (if you had one) ALSO connects to a buss that goes to the ground and that center tap.

Why two wires going to ground instead of one? If there is no current going through the appliance, both wires remain at ground potential, which is zero volts. When the appliance is powered on, the white wire doesn't quite remain at ground potential, but since it has resistance and current flowing through it, has a slight voltage. The ground wire, having no load on it, remains at zero volts. OK so far?

IN THEORY, the cases of appliances are isolated or electrically insulated or non-conductive (plastic cases on drills, etc.). If the case is metal, it is connected to the ground. That way, IF there is a short where the hot wire touches the case, it will be immediately grounded and trip the breaker or fuse, cutting off the power and making it safe. Chances of that happening are small, especially if you have the polarity correct.

Now, if the white or neutral wire shorts to the case, nothing will happen until the appliance is powered on, and then both the ground AND the neutral will be above ground potential. If you are not standing in water, the difference isn't usually enough to be a problem. However, in a kitchen you can be holding the refrigerator door handle with one hand and working in the sink with the other, or could have spilled water on the floor and be standing in it. In that case, the small current could kill you. Hence, Ground Fault Interrupter (GFI) circuit protection, which notices the neutral fault in the circuit that goes to the ground wire, and cuts off the circuit. GFI circuits are now required by code in bathrooms and kitchens, and the trend is to put them elsewhere, such as exterior circuits and bedrooms.

As long as your refrigerator has no abraded wiring insulation (from movement or mice), as long as the drain tray doesn't overflow or ice build up to the point that it bridges electric wires or contacts, as long as you keep your floor dry and hands away from the sink, then the socket is pretty safe to use. However, it is no where near as safe as current technology and standards could make it. Like anything, you take a calculated risk.

For those who think GFI sockets are perfectly safe, they are not. They too are a calculated risk.

Make more sense now?

................From looking at the top pic it appears that all the ground connections are on the Left side of the panel(small terminals) , with the hot wire connections being in the center of the panel . , fordy

I don't see a ground wire from the panel to a water pipe or a ground rod, is there one? What type of plumbing? If it's copper pipe you could ground to it possibly or put a rod in as Fordy said, probably the best bet.

It is not legal, or to code, or good enough for your insurance co to have a 3 prong outlet without the round hole connected to ground all the way to the main box buss.

It is equally as safe to have the unconnected outlet or a cheater plug BUT for one thing:

Anyone else living in or buying your house will assume the 3 prong outlet is a to-code grounded outlet, and so you are setting up a dangerous trap for any future owners or residents of the house. We all forget, and then we all assume, and that makes it dangerous.

So that is why cheaters are allowed, and hard-wiring an un-cionnected outlet is not allowed.


There is _one_ possible way to allow this, to be legal and safe and to code. There is a special way to hook up a (dern it, my brain isn't working this morning, what are they called???) outlets with a button on them, they snap off....

You get the right type of those, they come with a little sticker that labels the outlet as not having a grounded prong, and then everything is properly labeled and as protected as it can be, and the code and the insurance company will be happy, and you will be a little bit safer.

I am sorry my brain just isn't pulling up the right term for that plug in style, but this is the _only_ way to have a 2-wire outlet service a 3-prong outlet. It may not be allowed in a kitchen or bathroom either, you will need to look up the details on all this. Many will say this is not allowed at all, but in the tiny prrint in the fine details of the National Code, it is in there.

--->Paul

Very true Paul.
And if something unfortunate happens and a fire breaks out and it can be traced back to faulty wiring because of inadequate or not up to standards the insurance company may just say NO to paying anything out on something like that.

The main panel is grounded. That's an exterior wall, and I've seen the ground rod and wiring. That one line is the only wiring in the house that I've encountered that is 2 strand. I plan to change the outlet back to a standard 2 slot receptacle.

Where the fridge is now, I recently changed that outlet to a GFCI. It's 3 strand, and is grounded. My dad did update some of the house wiring, but never finished. What he did do was frustrating, running the lines, because of the way the house is constructed. It's a balloon frame. I remember him having to do some drilling to run wire and having a hard time getting to what needed drilled.

The only legal way to change out a two prong outlet without a ground is to replace it with a GFCI or run new wire with a ground. When an ungrounded outlet is replaced with a GFCI the GFCI needs to be labeled "No Equipment Ground" and will meet code, even without a ground. A GFCI usually comes with a set of stickers that will provide the needed label.

Many older homes were wired with 2 conductor romex and will not have a ground at the outlet box, knob and tube is even older and it never had a ground conductor either, so there are a lot of outlets without a ground in older construction. If properly installed, they are perfectly safe until you try and use an appliance than needs a safety ground.

Easy way put a white wire from silver screw to the green screw black on gold screw . White and ground end at the same place anyway if it is a newer unit it wont pull much juice. Have had to do this for copy machines where it would cost a bundle to do otherwise . Where people really mess up is they got a 15 amp wire on a 30 amp breaker then their wire becomes their breaker . when going to someone's house take your own smoke detector :bow:

There are three ways to handle the situation per code:

1. You can install a new 2-prong outlet and just have an ungrounded outlet. You CANNOT install a normal 3-prong outlet in place of it.

2. You can run a ground wire from the box to a good ground, a ground rod, your main panel ground, or a metal water pipe IF it's metal back to the ground and your meter is jumpered. Then you can install a 3-prong outlet.

3. You can as mentioned also install a GFCI outlet and apply the included "No Equipment Ground" sticker. This will make the outlet safe but it will still not be grounded. The idea is that the GFCI will keep anyone from getting shocked and it's even safer than a grounded outlet. Some equipment, mainly electronics will not operate well ungrounded. GFCIs are usually not reccomended for unattended equipment like a fridge because they can nuisance trip and you can come home to a warm fridge.

DO NOT jumper the neutral to ground. Under some circumstances the neutral will have a voltage on it and you'll get a shock from the cabinet of the fridge. Yes it will make an outlet tester read OKAY but you can get shocked like this.

Cfab if you can get shocked like that yuall got different lectric in the nauth than we got . Neutral from transformer to panel to ground rod then bond screw to case of panel :shrug: So that white wire should get you anyway you go :shrug:

Grounds are your friend. I would at least install a ground rod and run a new wire from the recept.

True and so is mine, which is the way it should be as the neutral will have to get to Ground so the electricity can get back to the source where it came from where ever that maybe~! To The power plant etc. That is why the better the ground the better it is on everything. You can think of electricty completeting a graet Big Circle. From the Power Plant to your home and then back to the power plant via the ground. :p

Not legal and not safe. Do not do this.

It 'works' unless you actually need the ground circut.....

Combining the neutral & ground wires more than only one time in the main breaker box sets up some really bad traps if any wires break - which is the point of the ground wire, and you defeat this point if you do as Sawmill says.

Bad advise. Real bad.


Don't think code allows one to run a seperate ground wire either, or connect to water pipe along the way, etc, tho I could be wrong on this.

Electricity needs 2 wires to work. A live feed (the hot wire) and a return path (the neutral wire). But if things go wrong, it is way safer for people to have a seperate totally dead wire - the ground wire. If you start swapping this dead wire with any of the others any old way you want, you create bad loops, and the possibility of all metal surfaces in your house to be lightly to strongly electrified.

The ground wire serves no purpose at all, _unless_ something goes wrong. So you'll never know you have it wired wrong until you really, really need it......

The ground wire is a safety feature. If you wire it up wrong as Sawmill says, then not only do you defeat the safty, but you may channel electricity from broken wires to any metal surface.

Don't do that.

So many get confused, because the neutral wire is sometimes called the ground, or negative, wire. But that isn't correct - it is the neutral wire. The ground wire is different.

So many get confused because they see the neutral & the ground wire bonded together inside the main breaker box - and assume they both go tot he same place, are tied together, and end up doing the same thing. That is wrong! It is like looking at your water supply, and saying since the water supply line is connected to both the cold water pipes and the hot water heater, all the water must be the same temperature. No, no. The ground wire is very different from the neutral wire, and needs to be isolated except at that one grounding spot in the main breaker box.

--->Paul

Neutral shouldn't be used for "grounding" because it's a current carrying conductor. Any voltage drop along the wire (there will be some) will be present in voltage at the case of the appliance if "grounded" as Sawmill Jim suggests. And in the case of a poor or broken connection on the neutral, full line voltage will be present on the case. It's a very bad idea to hook up something in this manner. If a separate ground wasn't necessary, don't you think they'd omit it and save 1/3 of the wire cost?

I agree with getting a book. They are really easy to follow and yeah it can be a pain in the butt speaking that I had to replace one in my 1940's house and it wasn't much fun but it wasn't difficult either. We have plaster and that by far was our biggest issue. Now when I say I, I do mean I did it. So if I can, I know you can :) And yes for those who are thinking-sure hope she had someone review that. I did have an engineer review everything I did to make sure I didn't do anything stupid ;)

I will be replacing the outlet with a GFCI. It's the best I can do right now, and safest. I'd love to have the entire place rewired for my mom, but that's just not possible right now.

I have a book, somewhere in storage, but haven't been able to locate it. I bought it over 6 years ago, but most of the info should be accurate.

Thank you everyone for the tips, advice and suggestions. I've learned a good bit about wiring. I know I have more to learn, but every bit helps.:bow:

IN an old house this is almost never the case.

VERY true.

YES it is... An ungrounded device is a single failure away from killing someone.