The mystery deepens in our ungrounded house

[Holly_Hobby]

I asked about grounding in this thread not long ago:

http://www.democraticunderground.com/11582887

So I buy a line tester and guess what? It says everything is wired correctly. So...is it the fuse box that's grounded? Because there are only 2 wires on each outlet.

TIA!

[Warpy]

1. Yes, it's grounded. If it's in the basement, you should be able to see a wire going to something

sunk into the concrete floor or to the drains. My breaker box is on an exterior wall and the grounding stake is outdoors just outside it.

[Holly_Hobby]

2. We're on a crawl space,

the fuse box is in our bedroom closet. The wiring goes directly behind it, through the wall to the meter.

In other words, the main wire comes off the pole, then down the outside of the house to the meter, then through the wall to the box in the closet.

My husband has recently confessed he's been looking for over 20 years for a stake...

In any event, the line tester says we're wired properly. Thanks for your reply.

[Callmecrazy]

3. The Utility wouldn't put a meter on your service if you aren't grounded...

And yeah, FHA would never have approved a loan for an ungrounded electrical system. If you have metal boxes, than you have metal conduit in the walls or flexible metal conduit that becomes the grounding system, The green grounding wire is redundant. You wouldn't believe how many redundancies are present in any electrical grounding system. It's the largest section in the National Electrical Code. I'm sure your home is perfectly safe. If you take off the front cover, called the deadfront (for obvious reasons), I'm sure you'll find a big fat bare copper wire in there going to ground. It's probably going to an iron rod sunk into the building footer.

[Hassin Bin Sober]

5. Oh yeah. I forgot about the footer ground.

Iirc, that's named after the guy who invented the system.

I read where they attach a line to a bar (rebar?) in the foundation footing. What better way to contact bare moist ground than a footing.

[Callmecrazy]

6. Yeah it's called something like ...

a Ufer ground?

[Hassin Bin Sober]

8. Yes! Ufer ground

From wiki


During World War II, the U.S. Army required a grounding system for bomb storage vaults near Tucson and Flagstaff, Arizona. Conventional grounding systems did not work well in this location since the desert terrain had no water table and very little rainfall. The extremely dry soil conditions would have required hundreds of feet of copper rods to be inserted into the ground in order to create a low enough impedance ground to protect the buildings from lightning strikes.
In 1942, Herbert G. Ufer was a consultant working for the U.S. Army. Ufer was given the task of finding a lower cost and more practical alternative to traditional copper rod grounds for these dry locations. Ufer discovered that concrete had better conductivity than most types of soil. Ufer then developed a grounding scheme based on encasing the grounding conductors in concrete. This method proved to be very effective, and was implemented throughout the Arizona test site.
After the war, Ufer continued to test his grounding method, and his results were published in a paper presented at the IEEE Western Appliance Technical Conference in 1963.[1] The use of concrete enclosed grounding conductors was added to the U.S. National Electrical Code (NEC) in 1968. It was not required to be used if a water pipe or other grounding electrode was present. In 1978, the NEC required rebar to be used as a grounding electrode if present. The NEC refers to this type of ground as a "Concrete Encased Electrode" (CEE) instead of using the name Ufer ground.
Over the years, the term "Ufer Ground" has become synonymous with the use of any type of concrete enclosed grounding conductor, whether it conforms to Ufer's original grounding scheme or not.[2]

[Hassin Bin Sober]

4. You never answered if your conduit was metallic cable or rigid metallic pipe

Based on what you are saying it must be metallic of some sort. If it is metallic cable or rigid metallic cable, then that is grounded somewhere along the line. The large service drop pipe from the power lines might be grounded.

The outlet receptacles become grounded when attached to the metallic junction box.

I'm in Chicago and we don't use the third/green/ground wire because we are required by code to use rigid metallic conduit. Our conduit is grounded. Romex is not allowed.

If you want to test my theory plug your tester in to an outlet receptacle that is hanging from the box and not contacting the box. When not in contact with the junction box it will show open ground. - turn the breaker off when handling the receptacle.

The only thing that now IS'NT grounded in your home is the modification your husband made using Romex. He broke the chain of grounded conduit. If he wants to ground that device he needs to attach the green wire to the junction box he pulled the power from.

[Callmecrazy]

7. Correct.

[Wash. state Desk Jet]

9. That what I couldn't figure out -the cable-pipe . it the only other way.

50's wire that replaced the old knot and tube was 12'2 without the additional copper ground.
it wired in about the same as knot and tube except the replacement wring was wrapped in insulation.Run up the wall to location the same way. Back than all junctions box's were metal.
Metal shielding over the wire was not and is not required unless it is a commercial building.

Although the commercial wiring is the way to go. Learn something everyday !

I didn't know rom ex isn't allowed in some areas.
Is that electrical code in Chicago for residential and commercial construction ?

And what about old homes and old commercial buildings that were wried in before the code was changed?

Say a 90 year old house ?
And what about remodel in old structures where tying in new materials with old stuff happens?

Code regulations along those lines in Chicago.

[Hassin Bin Sober]

10. Cook county doesn't allow Romex.

I suspect some of the other big metro areas like New York and Boston don't allow it.

All I know is the land of mrs. o'Leary's cow doesn't like it. Some say it's to keep the unions busy but I think it is more about fire code. The firemen don't like anything in plastic when they fight fires in big buildings due to the poison gas it emits. That's why we can't use PVC drains over three stories. I saw on a DIY show new york doesn't allow PVC shower pans for that reason.

I was checking out of Home Depot with a roll of MC lite cable and some electrician shook his head and said "they shouldn't even sell that shit here it's illegal"..... Yeah well it was for my own house and I was working in a really tight spot putting in some cans. We can use greenfield up to like three feet put I hate that stuff. The mc lite comes pre wired. Yeah you can never pull wire through it but so what. If I have a problem I'll open the ceiling.

I really do prefer met pipe over Romex. It does give you a lot more options. Plus extra added safety.

My brother's coworker's house burned. The fire inspector pointed out a nail that was in a piece of Romex. It was a drywall nail that was put in 15 years ago when the house was built. It finally decided to arc.

[Wash. state Desk Jet]

11. Good info. thanks.

electrical fires, scary stuff.

[Holly_Hobby]

13. No conduit, wires are covered in cloth n/t

[westom]

12. Some Confusion exists

> So I buy a line tester and guess what? It says everything is wired correctly.

Some previous posts have created confusion. A line tester (a plug in the receptacle one?) cannot report wiring as good. It can only report defects.

To know a safety ground exists requires inspection. To confirm a current path, seen by the tester, is actually a wire, is firmly attached, and is sufficiently thick.

Confusion also exists between safety ground and earth ground. Safety ground (ie in a wall receptacle) is completely different from earth ground. A line test may report that safety ground is disconnected. But it will report no change if the earth ground is disconnected or connected.

Earth ground (like safety ground) can only be confirmed by inspection.

Some irresponsible homeowners connect a white (neutral) wire to a receptacle's safety ground. Then a line tester reports as good what is a serious human safety problem.

Also distressing was a previous post where a receptacle safety ground was connected to a water pipe. Also a code and a human safety violation. A line tester might report that ground as good when inspection (and knowledge of code) says that ground is defective.

Appreciate that a line tester can only report defects; cannot report any connection as good. Appreciate that an earth ground is completely different from safety ground (that a line tester tests).

[Wash. state Desk Jet]

14. Yea the cheater ,where they take an end of the run hook a piece of wire to the neutral terminal than

than connect that to the ground terminal green.

Your concern about adding a safety ground to a circuit or plug is problematic, however look up adding a ground wire to a circuit or plug in.

What do you do if you cannot afford to have your home rewired when you need grounding plugs.
Look that up.