One plug grounded one not both three prong. Help!

Originally Posted By: ecrofutt
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Home 40 years old with green cloth covered cable for wiring in attic. No wiring in crawl space.


Two outlets 6 feet apart on living room wall. Both three prong.

100 Amp Square D main panel with ground wire visible on each cable leaving box.

Using the three light with GFCI trip button.

One outlet shows no ground. One outlet shows ground.

As I was alone and curious, I took the outlet cover off the outlet that showed a properly wired circuit with a ground. In the box and connected to the receptacle were two black and two white wires appearing to be properly connected to the line and load sides. No other wiring connected to the receptacle or visible in box. i.e. no ground wire visible.
No wire connected to the receptacle ground screw.

All three of my testers show a properly wired & grounded circuit.

Why would it show a ground?


--
Erby Crofutt
B4U Close Home Inspections
Georgetown, Kentucky

www.b4uclose.com

Originally Posted By: Walter Engelking
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Erby,


I’d be curious too, but what is the difference? You found a defect, plain and simple. Report it as such, and let your client (or owner, since it could be considered a safety issue) get an electrician to diagnose the repair. I feel that as an inspector it is only my job to report problems. I sure don’t have all day to track down loose ground wires.


Walter Engelking


Originally Posted By: rpalac
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Some receptacles are ground rated:


This means that mechanically you can complete the ground by the receptacle box being grounded and when you attach the receptacle to the box the frame of the box and the skeleton of the receptacle mechanically are grounded to each other. typically there is a metal spring clip of sort were the 10/32 screw is connected to the receptacle so it has a zero impedance and good connection.

If your tester shows a good ground, that is why.

If your tester shows a receptacle with a bad ground and when you observe a ground wire connected. You need to take caution. This means that ahead of that receptacle the ground id not complete.

* 1.) The best way to ground a receptacle is by the use of a ground wire from the incoming cable being directly wrapped around the ground screw . Such as what you were looking for.

* 2.) Some receptacles that you will see have the incoming ground wire connected to the back of the metal box and a short wire also grounded to the box and connected to the receptacle. This is also a continuity situation and is also acceptable.

* 3.) Some metal boxes are fed with pipe. Although piping is a great method and is mostly always acceptable as a ground continuity some installations are not acceptable. If the connectors are set screw type. That is okay. If they are compression type they are probably not rated for grounding and are not acceptable. Most piped installations are in commercial locations. These would also have a grounding tail connection between the back of the box and the receptacle or a grounding type receptacle.

* 4.) Of course as previously described, the receptacle can be ground rated. That screw that connects the receptacle to the box is the continuos path of the ground. The caution is that the box must also be properly grounded.

In all cases most people would insert the testing module and see if it shows a good ground. If it does, they accept it.

If it doesn't, It Must be Examined more closely by a qualified electrical to determine why the grounding conductor is not showing continuity.

Bob


Originally Posted By: jmyers
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Bob,


Let me make this a little simpler for you. If you are looking at the main panel and you are not seeing that third bare wire (the EGC) what you have are non grounding outlets (whether they are two or three prong).

There are certain conditions in the NEC that would apply when installing these types of outlets on a two wire system, such as GFCI protection. Even then, all the outlets would be required to be marked as such, GFCI protected, No equipment ground.

I applaud you for taking the receptacle cover off in your quest to find out the why's and how's but it also is dangerous for you and those that are around you. In the future it would be wise just to note that no EGC's were observed in the panel, although the house contained three prong outlets. Recommend further evaluation by an electrician and corrections made based on their findings.

Joe Myers


Originally Posted By: ecrofutt
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Quote:
100 Amp Square D main panel with ground wire visible on each cable leaving box


But thanks for contributing.

As regards:
Quote:
taking the receptacle cover off in your quest to find out the why's and how's but it also is dangerous for you and those that are around you.


I seldom do it, but it's not dangerous for those around me, because I don't do it when anyone else is around. It's not dangerous for me, because I turn off the breaker and use the tic tracer, and volt/ohm meter to ensure no power to the receptacle before removing the cover plate and the box after the cover plate is removed. If I can't make myself comfortable doing it, I just don't do it. OK, maybe the breaker won't reset. Was it "failed under testing" or do I pay the cost of replacing it. Evaluated on a case by case basis.

As for "further evaluation", I never use those words anymore, even though that might be what I'm saying with the language above. The client feels that's what I'm there for, "evaluation". Besides that, it sounds weasley to me.


--
Erby Crofutt
B4U Close Home Inspections
Georgetown, Kentucky

www.b4uclose.com

Originally Posted By: rpalac
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Erby,


I very much applaud you for not depending on those %^&*&%$$ blasted &*^^^*%%&(& tick tracers. A.K.A. voltage testers (they work on EMF ---- Not always present when cycles cancel) They DO NOT indicate the guaranteed absence of voltage. I could show you over and over situations where they wont work. More than likely they won't work on the cable feeding your monitor.

(Even more, I could show you in the field 480 volts and use a voltage meter and show you it is dead when it really is not..........The training of knowing grounded systems, un-grounded system, floating grounds and open legs has a lot to do with it....PART OF MY TRADE)

Anyhow, you seem to have taken a lot of care in procedures to ensure your safety. I believe that Joe was trying to just speak from not only a safety point but a liability point. Some times we open up a box and it's a rat nest that you can't get back together. I myself have been cuaght up in it many of times. One time I remeber opening a splice box while crawling in a ceiling and the insulation crumbling off half the wires.....NOW WHAT! what a mess that was (The old RH wire)

I got his message, but we all do what we feel is necessary or right. We don't like to hear about our colleagues getting hurt. Joe is well seasoned in this industry and highly respected. I work in the same area as Joe and heard a lot of positives about him. I'm sure you are respected in your area, but we can never be to safe. I have seen first hand on more than one occasion an inspector get zapped because he didn't know what he was doing in a compartment. Especially when it comes to heating and A/C. You did make me feel comfortable by saying the procedures you took and the fact that you were very safety conscious.

I like your view of using terminology that does not negate what customers expect us to do. I'm glad to have been able to help at all if I did, but it seems like you already had it figured just a slight laps in thought.

bob


Originally Posted By: Mike Parks
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Erby


I'll bet one of the boxes is metal. The screws holding the outlet on will "give" you the egc reading. Probably a bootleg ground? Maybe, maybe not.

It is very hard to tell without being there and testing.

Mike P.


Originally Posted By: dhartke
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Bob,


In residential do you often find a multimeter not detecting the presence of voltage, if so, where or when?

Dave


Originally Posted By: jfarsetta
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Erby,


Been there, done that... as well. Bravo.

I agree with Robert's assessment that the box was most probably grounded, and the receptacle frame (or mounting tabs) provide the mechanical bond from the box to the grounded portions of the receptacle.

And, your right. A little investigation can go a long way.


--
Joe Farsetta

Illigitimi Non Carborundum
"Dont let the bastards grind you down..."

Originally Posted By: dhartke
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Mike,


If it has a bootleg ground wouldn't he have seen the wire connecting the grounding and neutral screws on the receptacle or is there another way?

Dave


Originally Posted By: ecrofutt
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Quote:
those %^&*&%$$ blasted &*^^^*%%&(& tick tracers
but then I figured it meant you REALLY don't like them and left it at that.

Mike is right, the box I opened was metal.

How's this for a rat's nest, in the same house.

http://www.nachi.org/bbsystem/usrimages/DSC06605.JPG

This is the stuff I stay far away from. Plenty of reason here to tell the client, "consult a licensed, qualified electrician (like Mike) to determine the best repair method, estimate costs, and perform the necessary repairs."

Or, in other words: have an electrican further evaluate it. figure out the best way to fix it, tell you how much it's gonna cost and then have it done by the electrician.


--
Erby Crofutt
B4U Close Home Inspections
Georgetown, Kentucky

www.b4uclose.com

Originally Posted By: Mike Parks
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Dave


It could be "effectively" grounded, by accident. Touching a grounded conductor or an equipment grounding conductor or a bonded (ie) water line.

Hard to explain over the net.

Mike P.


Originally Posted By: lfranklin
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OK Erby, let me take a guess here to icon_confused.gif


If I understand the question right, the first receptacle would be grounded through the box like Bob said. Now were guessing from that receptacle, there is still some older (only two wire system) going to the second receptacle.


Originally Posted By: jmyers
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Erby,


Sorry, I misread what you wrote. I am having a brain freeze day and it is not getting any better.

Joe Myers


Originally Posted By: ecrofutt
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At’s Okay Joe. I had three brain farts today. Thank god it’s almost over. Yeah Larry, could be something like that. I’m not real up to date on when the green cloth covered cable was used but the house was 43 years old, built around 1960. See the attic picture above.


No aluminum wiring present. Galvanized pipe had all be replaced with copper.


--
Erby Crofutt
B4U Close Home Inspections
Georgetown, Kentucky

www.b4uclose.com

Originally Posted By: rpalac
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Dave,


to answer that....
Quote:
Bob,

In residential do you often find a multimeter not detecting the presence of voltage, if so, where or when?


No I have seen this in commercial. There are what are referred to as non-grounded systems. You find these in some mills and dairies especially.
In residential I have always been able to detect to ground via a multi meter. I could imagine that if the service was not properly grounded and the pole transformer had less than needed in ohming to ground...there is a remote possibility but highly unlikely.

Quote:
I tried to interpret what you meant by Quote:
those %^&*&%$$ blasted &*^^^*%%&(& tick tracers
but then I figured it meant you REALLY don't like them and left it at that.


Yes, you are right......I despise the use of the neon voltage indicates that a lot of people rely on. They are dangerous and can create a very false sense of safety. If you hold one up to a twisted pair it will not read voltage due to the cancellation of the magnetic field. Try it, you'll see what I mean. Additionally if the battery is bad or the dies you wouldn't know unless you used it again on something live. All-in-all even in the field I cringe when I see a fellow sparky using them........


Bob


Originally Posted By: ecrofutt
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I just chose never to rely on a tic tracer alone when I’m going to be touching something that might or might not be hot.


I find it is a good positive indicator, but a crappy negative indicator. By which, I guess, I mean I trust it to tell me that electricity is there, but I don't trust it to tell me that electricity is NOT there.

They should always be tested on a known hot wire prior to each use to make sure the battery hasn't failed.


--
Erby Crofutt
B4U Close Home Inspections
Georgetown, Kentucky

www.b4uclose.com