Metal boxes with conduit back to the panel are grounded, right?

[yrag.neslo]

My brother and his 30-year old kid are upgrading outlets in my mom's late 4

0's house. The post WWII house was built using a new construction technique at the time--reinforced concrete with ample rebar. All the electrical is 2

-wire, in conduit that goes back to the breaker.

Nephew (who installs security systems) has taken out numerous outlets and i s measuring wiring and boxes with a multimeter saying they're not adequatel y grounded. I'm not involved with the project, but when I put a test light between hot and the metal outlet box and it lights up, it sure looks ground ed to me. I told him to tap the box and install a green ground wire between the box and the new outlet.

In addition to all this, I found he did a "bootleg ground" in an outlet and I cut it out. It took awhile to convince my brother and his kid that a "bo otleg ground" is worse than no ground at all. The kid insists that an "old time electrician" would do it that way.

Bottom line--if the wiring is ok, and a test light lights between the metal box and hot the box is grounded, right?

[Stormin Mormon]

IANALE (I am not a licensed electrician).

Test light uses a lot less current flow than a 100 watt light bulb for example. So, the test light might be OK with a weak ground.

[trader4]

40's house. The post WWII house was built using a new construction techniq ue at the time--reinforced concrete with ample rebar. All the electrical is 2-wire, in conduit that goes back to the breaker.

is measuring wiring and boxes with a multimeter saying they're not adequat ely grounded. I'm not involved with the project, but when I put a test ligh t between hot and the metal outlet box and it lights up, it sure looks grou nded to me. I told him to tap the box and install a green ground wire betwe en the box and the new outlet.

I thought we went through this is an earlier thread couple weeks ago. Yes, metal conduit that is properly installed is allowed as an eqpt grounding conductor. You don't say what your brother is measuring to come to the conclusion that it's not properly grounded. The fact that a bulb lights is one indication that it's probably OK. But we can't see what's there or how it's all done. I can think of ways where a bulb would light and it's not done right.

nd I cut it out. It took awhile to convince my brother and his kid that a " bootleg ground" is worse than no ground at all. The kid insists that an "ol d time electrician" would do it that way.

Is the "bootleg ground", using a water pipe in the kitchen which is what you were talking about last time? Is so, that is a code violation to install it today. What anyone did or didn't do in the past is irrelevant

al box and hot the box is grounded, right?

Probably. We still don't know the specifics of why your brother has taken measurements that lead him to believe otherwise.

Also, from the scope of the work here, in most places, as was pointed out before, with a kitchen remodel, permits are required. A nd to do a kitchen remodel, I think you typically need to bring it all up to current code, ie GFCIs, correct number of outlets, 20 amp circuits, etc.

[gfretwell]

If you get something like the Ideal Sure Test it will check that ground with a load on it. Ecos makes a plug in tester that is similar

[yrag.neslo]

This is not a kitchen remodel. Different issue. Wiring is original. Original 1940's outlets have never been removed since installation.

The bootleg ground was an outlet where he'd jumped neutral and ground.

[Stormin Mormon]

Jumping N and G, doesn't that risk making the chassis of the device hot, if the white wire is broken?

IANALE.

[RobertMacy]

Calling it ground, don't make it so. Using neutral as a ground ...a long way from where neutral may, or may not, be connected to pipe ground; has to be one of the most 'unsafe' things to do in the world.

Just test the voltages you can get at that 'ground' connection during a reasonably normal fault! Assuming there's such a thing as a normal fault.

[trader4]

And if that neutral ground "bootleg" connection is done anywhere along the circuit run, then the "lamp lights from hot to ground" anywhere else along that circuit is meaningless in determining if it's properly grounded. IMO, the brother doing this is clealy unqualified to be doing the work. Who knows what else he's doing that's dumb. Brother #2 who's here appears to be on the right track.

[yrag.neslo]

Yes.

[Doug Miller]

[e-mail] wrote in news: [e-mail]:

Not necessarily, depending on your definition of "the wiring is ok".

If a test light lights between the metal box and hot, that means the box is connected *either* to a good ground, or to the neutral conductor.

Turn off the breaker and disconnect the circuit neutral from the bus bar in the panel, then use a continuity tester or ohmmeter to determine if there is a connection between neutral and ground. If there is, then the wiring is not ok -- you need to find out where they're connected, and separate them.

[bob haller]

its a good idea to put a 100 watt incandescent bulb between hot and your perspective ground, in this case the conduit.

It should light brightly.

home inspectors just use neon bulb circuit testers.. NOT trustworthy if you ask me

[yrag.neslo]

That's what I meant. Obviously if neutral is connected to the box the wiring is not ok.

[Tony Hwang]

Hi, Another way to check is to see if there is potential between N and conduit at either end. If there is difference(presence of voltage when measured), you know the grounding is POOR.

[micky]

Makes sense. Tests for a good ground.

But just to be clear, doesn't exclude the bootleg ground. A bad ground with the bootleg ground described here, G to N, will also light the light brightly. Did the kid put in one only (which the OP took out) or did he put in more than one? And will he say? In the 50's TV shows I've been watching lately, the kid always does something wrong and is afraid to say that he did.

I think you're right. I'll watch and bear that in mind.

[trader4]

That's why Doug Miller suggested to remove the neutral connection at the panel when doing the test.

Did the kid put in one only (which the OP took out) or

It's not a kid, he's 30 years old. That's at least 3 years past even the new lib definition of a kid, which ends at 27. He also has his father working with him. Probably would be better off with a real kid from what we've heard they've done and think so far.

[trader4]

If there is current flowing, there should be some voltage between the neutral and ground. One conductor is carrying current, the other should not be. If you had a 50 ft 14 gauge run, with a 10 amp load, you should see about 1.25 volts, possibly more depending on how the wiring connections are made. The neutral is daisy chained, with possibly many connections in between. And alternately, if they have one of their "bootleg" connections at an outlet between neutral and ground, then you wouldn't see any voltage difference between neutral and ground or maybe just millivolts and it's not a proper ground.

In this case, Doug's suggestion of disconnecting the neutral at the panel and then doing a light bulb test between hot and ground looks like the best test that really works to me and it's easy.

I also hope that they are installing GFCIs on the kitchen, bath, outside, where required circuits.