# For better or worse?



## neolitic (Apr 20, 2006)

Northernboy said:


> Why don't you just carry one extention cord with the ground snipped off, instead of replacing receptacles everywhere you go? Am I the only one who has one of those?


Used to work with a guy that thought like that. If that cord wasn't handy, snip another, and another....then can't find one that _has _a ground. When he did it to one of mine, I deducted $89 from his check for a new 50' #12 all-weather. Last job we did together.(other "incompatibility" issues as well) 
As much to the point as anything, _sometimes_ a 70-80 year old outlet has lost a little of it's "spring" and won't even hold a lamp plug any more---I know, _that's what duct tape is for_!


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## neolitic (Apr 20, 2006)

Dustball said:


> Wikipedia saves the day. Basically the conduit turns into an inductor- http://en.wikipedia.org/wiki/Inductor
> 
> http://electronics.howstuffworks.com/inductor1.htm


Since that seems to make some sense to me--_it must be wrong!_
But----
*THE ANSWER IS....*---I won't leave them on a job from now on. If they won't spring for the GFCI, they get new 2 prong.:innocent: (I will however leave 'em in at _MY_ old house,places where I can't actually run new grounded cable.)
Thanks All!


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## 220/221 (Sep 29, 2007)

> A) Isn't this a better path to ground than say through a person?


Yes




> B) Should it still be taken out and replaced with a 2 holer?


no


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## Speedy Petey (Sep 30, 2003)

220/221 said:


> Yes
> 
> 
> 
> ...


How, and why not?

What if the cable is old BX cable with no bond strip? 
What if there is a ground fault but not through a person? 
What if there is current on the ground and there is a loose or corroded connection at a fitting or box? 
What happens at that fitting if current is present????????
Do you have the number for 911 handy?


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## 220/221 (Sep 29, 2007)

> How


If the electricity flows thru a person it could kill them?




> why not


Because it is grounded and will trip the breaker in case of a fault?


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## Speedy Petey (Sep 30, 2003)

220/221 said:


> Because it is grounded and will trip the breaker in case of a fault?


Really? What if it is not a bolted fault? What if it is simply a ground fault? I have seen cases of improperly grounded AC cable glowing red because of the heavy current from a fault. I have personally seen fires start because if this.
Is this better than properly grounding, or better than using a two-prong receptacle?


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## jrclen (Jul 10, 2007)

Sparky Joe said:


> I'm no engineer, but it seems to me that the construction of flex is why it's not used as a ground as opposed to conduit.
> This has nothing to do with corrosion over time because everything steel corrodes, and most flex nowadays is aluminum, but the rule still applies.
> 
> I'd say it's because the ground fault current carrying path is being run parallel to itself. One ring is parallel to the next, thus one ring's magnetic field would choke off the current carrying capability of the next ring. But each ring is touching, hence no more than 6 feet.
> ...


I was taught the same thing years ago. The spirals would act as a choke, causing a high impedance ground path that might not conduct enough current to open the over current device during a ground fault. In addition, the high impedance could cause heating of the flex that could start a fire. I would not use ac or bx for a ground. I replace 2 holers with another 2 holer or I install a GFCI recept.


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## 220/221 (Sep 29, 2007)

> I have seen cases of improperly grounded AC cable glowing red because of the heavy current from a fault


Steel glowing red hot???? Cool!

Was there a functional circuit breaker/fuse in this case?

Details please. I'm always up to learn something new.

And PLEASE....not scientific details. I won't be able to understand them. I want to know what happened to cause this situation and the details of the circuit that faulted.


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## Sparky Joe (Apr 29, 2006)

Hey "220", read JR's post above and if it doesn't make any sense then it's time you start school and stop calling yourself an electrician.

The ground fault in the flex would induce too much impedance to trip a breaker, but yet energize the entire grounding system, then someone touches a light switch in their garage or basement(concrete floor), and pow, your neat trick to make a buck just killed someone.


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## mdshunk (Mar 13, 2005)

220/221 said:


> And PLEASE....not scientific details. I won't be able to understand them. I want to know what happened to cause this situation and the details of the circuit that faulted.


The coiled steel, without the bonding strip to "short" the coils, is now an inductor. Flow current through a long inductor, and you have yourself a fine heating element.


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## Speedy Petey (Sep 30, 2003)

Thanks guys. :thumbsup: 
I was at a meeting tonight.


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## 220/221 (Sep 29, 2007)

Sparky Joe said:


> Hey "220", read JR's post above and if it doesn't make any sense then it's time you start school and stop calling yourself an electrician.


Why don't you ever answer simple questions SpankyJoe?


You have never EVER seen a glowing piece of MC and you know it. 




mdshunk, wouldn't the overcurrent device clear the circuit? It's NOT a heating element, it's a piece of steel??


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## Sparky Joe (Apr 29, 2006)

220/221 said:


> mdshunk, wouldn't the overcurrent device clear the circuit? It's NOT a heating element, it's a piece of steel??


And a motor is just a piece of copper, 
Is that non-scientific enough.


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## mdshunk (Mar 13, 2005)

220/221 said:


> mdshunk, wouldn't the overcurrent device clear the circuit? It's NOT a heating element, it's a piece of steel??


Nope.... place enough inductance in a circuit, and you can have a 17 amp fault (for instance) cook away all day. As Joe rightly points out, a motor (and a transformer) are just copper wire, wound as an inductor for useful purposes. That's why we wind motors and transformers with varnished wire, so that they maintain their inductive properties and don't "short" the winding. The old BX, without the bond strip, is the same thing; an inductor. Consider also that this is why the code won't let you run more than a certain amount of Greenfield for use as a ground for this reason. Short pieces are fine, since there's little inductance. Longer pieces, now that's an inductive heating element right there. 

Conseqnently, ever used one of the newer style hot boxes for bending PVC (they're tubes generally) that are inductive heaters? They don't have a traditional heating element like the hot boxes we're used to. They're a coil of wire wrapped around a tube. Put your PVC inside, and it gets all warm and toasty. :thumbsup:


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## mdshunk (Mar 13, 2005)

220/221 said:


> Why don't you ever answer simple questions SpankyJoe?


Joe's still full of the requisite amounts of piss and vinegar that come with youth.  His heart's in the right place normally.


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## Sparky Joe (Apr 29, 2006)

mdshunk said:


> Joe's still full of the requisite amounts of piss and vinegar that come with youth. His heart's in the right place normally.


Piss and Vinegar are what keep me going :thumbsup:

And I'm not sure a scientific question can be asked without recieveing a scientific answer?
But if it's simply "in one end and out the other", and let the ocpd do the rest. I suppose I wasted a few bucks on all those years of schooling.


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## neolitic (Apr 20, 2006)

Sparky Joe said:


> Piss and Vinegar are what keep me going :thumbsup:.


Ran out of vinegar a while back, seem to be over supplied with the other lately though:sad:
Getting old ain't for the faint of heart.


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## Sparky Joe (Apr 29, 2006)

neolitic said:


> Ran out of vinegar a while back, seem to be over supplied with the other lately though:sad:
> Getting old ain't for the faint of heart.


At least one of the two are still keeping you going............even if it is just to the bathroom.

Get it; piss and going to the bathroom, hahaha

sorry about that


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## neolitic (Apr 20, 2006)

Sparky Joe said:


> At least one of the two are still keeping you going............even if it is just to the bathroom.
> 
> Get it; piss and going to the bathroom, hahaha
> 
> sorry about that


That's the point exactly.:thumbsup:


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## 220/221 (Sep 29, 2007)

> place enough inductance in a circuit, and you can have a 17 amp fault (for instance) cook away all day.


How would one do that?


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