Article 100 Definition Addition! SHORT CIRCUIT

[roger]

Short Circuit; A circuit of short length, example; A dedicated circuit to a receptacle underneath a panel board connected with a chase nipple.

Problem solved. :wink:

Roger

 

[ibew441dc]

Be genuine and honest with your point of view.

Be genuine and honest with your point of view.

Here are questions that I pose to all. We are the qualified persons that are reading in to this stuff.

(1)What is a Short Circuit?

(2)What is a Ground Fault?

(3)What is Objectionable Current?

(4)What is an Arc Fault?

(5)Is a Ground Fault a Short Circuit?

(6)Is a Short Circuit a Ground Fault?

(7)Is an Arc Fault a Short Circuit?

 

[ibew441dc]

Short Circuit; A circuit of short length, example; A dedicated circuit to a receptacle underneath a panel board connected with a chase nipple.

Problem solved. :wink:

Roger

Roger I am deleting this post in accordance with the rules of this forum:grin::wink: Too much common sense is dangerous, one might suggest a short circuit is a good thing......or is it?:grin:

 

[don_resqcapt19]

(1)What is a Short Circuit?
An unintentional current path between two or more ungrounded conductors, or between an ungrounded conductor and a grounded conductor, or between an ungrounded conductor and the EGC or other conductive path.
(2)What is a Ground Fault?
One type is a subset of a short circuit...a path between an ungrounded conductor and the EGC or other conductive path. The second type is a grounded to grounding conductor connection on the load side of the main or system bonding jumper.
(3)What is Objectionable Current?
No one knows.
(4)What is an Arc Fault?
A short circuit or ground fault that is not solid connection.
(5)Is a Ground Fault a Short Circuit?
It can be if is between an ungrounded conductor and the EGC or other conductive path.
(6)Is a Short Circuit a Ground Fault?
Sometimes.
(7)Is an Arc Fault a Short Circuit?
No.

 

[iwire]

Obviously:roll::smile:, My opinion is now biased in this regard, and so is yours. How do we come to a conclusion if both are convinced that either (a) the definition would provide clarity and be beneficial ,or (b) the definition is unnecessary and would be of no benefit

The NEC is not a design manual or instructions for the untrained. The stated purpose of the NEC is providing safe electrical installations

I am asking a straight forward question that you can't seem to answer.


How would adding a definition of 'short circuit' into Article 100 increase electrical safety?

Keep in mind these are the types of questions the CMP will be thinking about.

 

[iwire]

(3)What is Objectionable Current?
No one knows.

Objectionable Current, now that is a term I could get behind a definition for as that is not a commonly used term.

 

[ibew441dc]

The NEC is not a design manual or instructions for the untrained. The stated purpose of the NEC is providing safe electrical installations

I am asking a straight forward question that you can't seem to answer.

IWIRE, you have not asked me such a question until now. (paraphrasing)You asked me where in the code it may cause confusion, and I have answered that.

How would adding a definition of 'short circuit' into Article 100 increase electrical safety?

Keep in mind these are the types of questions the CMP will be thinking about.

Adding the definition of 'short circuit' would increase electrical safety by identifying language as to avoid dialog confusion of a commonly used term among qualified persons, clearly illustrating the portion of a circuit that has the highest fault current available at that point.

 

[quogueelectric]

IWIRE, you have not asked me such a question until now. (paraphrasing)You asked me where in the code it may cause confusion, and I have answered that.



Adding the definition of 'short circuit' would increase electrical safety by identifying language as to avoid dialog confusion of a commonly used term among qualified persons, clearly illustrating the portion of a circuit that has the highest fault current available at that point.

I think that a ground fault definition should be any conductor other than a ground that has faulted to ground. How was that for starters?
Kind of like keep it simple.....

 

[quogueelectric]

Short Circuit; A circuit of short length, example; A dedicated circuit to a receptacle underneath a panel board connected with a chase nipple.

Problem solved. :wink:

Roger

Fed off the bottom breaker??

 

[George Stolz]

Adding the definition of 'short circuit' would increase electrical safety by identifying language as to avoid dialog confusion of a commonly used term among qualified persons, clearly illustrating the portion of a circuit that has the highest fault current available at that point.

You're ignoring the fact that a short circuit could include an ungrounded and grounded conductor making contact after the service disconnect.

Is there a lesser level of PPE I must wear if I'm only going to be exposed to a ground fault? I must have missed the memo...?

 

[ibew441dc]

You're ignoring the fact that a short circuit could include an ungrounded and grounded conductor making contact after the service disconnect.

I am not ignoring that at all.

Adding the definition of 'short circuit' would increase electrical safety by identifying language as to avoid dialog confusion of a commonly used term among qualified persons, clearly illustrating the portion of a circuit that has the highest fault current available at that point.

I did not specify line to line ,or line to grounded conductor because it could be either of the two in the appropriate setting (neither of the two are ground faults). My logic still applies to an ungrounded and grounded conductor because if they were the only conductors together the fault current would be higher than an ungrounded to EGC fault(ground fault).

Is there a lesser level of PPE I must wear if I'm only going to be exposed to a ground fault? I must have missed the memo...?

I don't understand this comment ? are you implying that an ungrounded to grounded conductor is a ground fault?:-? A short circuit will always have a higher value than a ground fault in the same circuit.

 

[ibew441dc]

Short Circuit-Added to correlate with the use of the term throughout the Code.

Short Circuit-Added to correlate with the use of the term throughout the Code.

Originally Posted by IBEW441DC
Short Circuit-An intentional or unintentional, low impedance conducting connection, between any ungrounded conductor(s) establishing a difference of potential, or between any ungrounded conductor(s) and a grounded conductor,or between any ungrounded conductor(s) and an equipment grounding conductor.

FPN (1): A Ground Fault is not a short circuit when subject to high impedance (see Article 250.2 Definitions).
FPN (2): An Arc Fault is not a short circuit due to high impedance.
FPN (3): A Short Circuit is not an intentional or unintentional electrical conducting connection between a grounded conductor and an equipment grounding conductor.(see 250.6 Objectionable Current) An example of objectionable current is neutral current flowing on paths other than permitted by the Code.

After thorough consideration and thought, based on different resources, the NEC, and those who have included themselves in this discussion, I have come to what I think would be both beneficial and reasonable(see above). Why add this definition? Add this definition to correlate with the use of the term throughout the Code.

(note-The definition of neutral conductor was introduced into Article 100 in 2008 for the exact same reason. The addition of Neutral Conductor was derived from the IEC ,and influenced by IEEE C57.12.80-2002 definition of neutral point. There was no safety influence it was merely added to correlate with the use of the term throughout the code.)

 

[don_resqcapt19]

I don't see any confusion in the application of the code now and see no need for a definition of short circuit.
As far as the neutral conductor, that was an undefined term in the NEC, but it took at least 3 code cycles to arrive at a workable definition.

 

[George Stolz]

My logic still applies to an ungrounded and grounded conductor because if they were the only conductors together the fault current would be higher than an ungrounded to EGC fault(ground fault).

I don't understand - why do you say the fault current would be higher from ungrounded to grounded than ungrounded to grounding?

 

[jim dungar]

My logic still applies to an ungrounded and grounded conductor because if they were the only conductors together the fault current would be higher than an ungrounded to EGC fault(ground fault).

Almost more than the voltage, the impedance in the fault path dictates the amount of current that flows during a fault. All other things being equal, the highest amount of current occurs during a bolted fault condition and the lowest during an arcing fault. It is possible to have a bolted ground fault with a 'high current' value and an arcing short circuit fault with a 'low current'.

I suggest that a short circuit is simply a fault path that bypasses the intended load.

The Soares Book on Grounding and Bonding says: "Ground Fault Current Path. ' An electrically conductive path from the point of the ground fault on a wiring system through normally non=current carrying conductors, equipment, or the earth to the electrical supply system'".

Yes 250.2 contains a specific definition of ground fault, for use in article 250, that says a downstream bonding of the grounded and grounding conductors is not a ground fault. However, this restrictive definition ignores the realities of how 'Ground Fault' protection schemes and devices are actually constructed.

 

[ibew441dc]

I don't see any confusion in the application of the code now and see no need for a definition of short circuit.
As far as the neutral conductor, that was an undefined term in the NEC, but it took at least 3 code cycles to arrive at a workable definition.

"Neutral" was defined for many years in the same manner that "Short Circuit" is defined now. It was assumed to be understood using outside references. For the sake of argument, forget my interpretation of Short Circuit, even if the NFPA would include a definition of their choosing in the Code, it would be appropriate.

 

[ibew441dc]

I don't understand - why do you say the fault current would be higher from ungrounded to grounded than ungrounded to grounding?

Thank You for helping me illustrate my point. What is the definition of a short circuit?:smile:

If we can agree that a Short Circuit is a low impedance connection,establishing a path intended or unintended .....then we can both open our eyes to this.

An Arc Fault is not a short circuit.(why..high impedance)
A Ground Fault is only a Short circuit when it is not subject to high impedance.

It is true that fault current from Hot to Neutral, or the same Hot to an associated EGC of the wire type, would have the same fault current (given the same size,length,conductor type,ect). Assuming that everything is in proper working order, a fault from the same hot to any other EGC would be higher due to the impedance of the available paths(which in reality are not going to be copper).

 

[ibew441dc]

My logic still applies to an ungrounded and grounded conductor because if they were the only conductors together the fault current would be higher than an ungrounded to EGC fault(ground fault).

Almost more than the voltage, the impedance in the fault path dictates the amount of current that flows during a fault. All other things being equal, the highest amount of current occurs during a bolted fault condition and the lowest during an arcing fault. It is possible to have a bolted ground fault with a 'high current' value and an arcing short circuit fault with a 'low current'.

I suggest that a short circuit is simply a fault path that bypasses the intended load.

IMO the key difference is the impedance. A Short Circuit has low impedance. A ground fault is not a Short Circuit when subject to high impedance. An Arc Fault is not a Short Circuit due to high impedance. A "Bolted Fault" line to line,line to neutral, or line to EGC is a Short Circuit due to low impedance. By the way where did you come up with "Bolted Fault" :grin:?

 

[don_resqcapt19]

"Neutral" was defined for many years in the same manner that "Short Circuit" is defined now. It was assumed to be understood using outside references. For the sake of argument, forget my interpretation of Short Circuit, even if the NFPA would include a definition of their choosing in the Code, it would be appropriate.

I could see where there was a code application or use impact with the term neutral...I just don't see that for "short circuit".

 

[ibew441dc]

I could see where there was a code application or use impact with the term neutral...I just don't see that for "short circuit".

Fair enough. Then we agree to disagree:smile: