Article 100 Definition Addition! SHORT CIRCUIT

[jim dungar]

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:?

The NEC addresses these faults based on their path.
Overcurrents - excess current flowing through the entire intended circuit conductors including the load.
Short Circuits - current flowing along portions (i.e. not through the load)of the intended circuit conductors.
Ground Faults - current flowing outside of the intended circuit conductors.

You appear to want the NEC to define these faults based on the voltage drop across the 'fault' (i.e. its impedance). However, the amount of impedance in a fault (arcing, bolted, or excessive loading) is not always path related.

 

[quogueelectric]

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.

Do you currently agree that the definition of Ground Fault is adequate???

 

[ibew441dc]

Originally Posted by 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.

quogeelectric's question to don_resqcapt19

Do you currently agree that the definition of Ground Fault is adequate???

My answer to quogeelectric's question to don_resqcapt19

I think the definition of Ground Fault is appropriate, if its relationship to Short Circuit and Objectionable Current was cleared up.

Ground Fault. An unintentional, electrically conducting connection between an ungrounded conductor of an electrical circuit and the normally non?current-carrying conductors, metallic enclosures, metallic raceways, metallic equipment, or earth.

My opinion of it being cleared up is....

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.

 

[quogueelectric]

quogeelectric's question to don_resqcapt19


My answer to quogeelectric's question to don_resqcapt19

I think the definition of Ground Fault is appropriate, if its relationship to Short Circuit and Objectionable Current was cleared up.



My opinion of it being cleared up is....

Not acceptable!!! without provisions for all ground fault instances. Simply NOT acceptable.

 

[ibew441dc]

Not acceptable!!! without provisions for all ground fault instances. Simply NOT acceptable.

What do you propose? How does it not define provisions for all ground fault instances already?......Forget about my fantasy definition for a minute.

Lets stick with the one that some hold to as gospel.

"McGraw-Hill Dictionary of Scientific and Technical Terms." It has the following definition of "short circuit":

A low-resistance connection across a voltage source or between both sides of a circuit or line, usually accidental and usually resulting in excessive current flow that may cause damage.

So in this case a Ground Fault of high "resistance" is not a short circuit.

Ground Fault. An unintentional, electrically conducting connection between an ungrounded conductor of an electrical circuit and the normally non–current-carrying conductors, metallic enclosures, metallic raceways, metallic equipment, or earth.

A neutral to egc fault is not defined as a Ground Fault, its obviously not line to line and how could it be across the voltage source. Process of elimination, Neutral to egc is objectionable current, based on info in 250.6.

 

[don_resqcapt19]

Do you currently agree that the definition of Ground Fault is adequate???

Yes as it describes the type of ground fault that we use an OCPD to protect from.

 

[ryan_618]

I also don't see the need for a definition, although I applaud your desire to help clear things up. I simply don't think that adding a definition makes the Code a better document. I agree with Pierre's statement that people become more educated by going to school and by educating themselves. I think adding this term to Article 100 is another example of the Code stepping outside of its scope and purpose of 90.1(C), which specifies that the document is not for untrained persons.

 

[ibew441dc]

errrrr!!!!

errrrr!!!!

I also don't see the need for a definition, although I applaud your desire to help clear things up. I simply don't think that adding a definition makes the Code a better document. I agree with Pierre's statement that people become more educated by going to school and by educating themselves. I think adding this term to Article 100 is another example of the Code stepping outside of its scope and purpose of 90.1(C), which specifies that the document is not for untrained persons.

Well Ryan_618....Obviously you don't know what your talking about!

Just Kidding:grin:....Just Kidding:grin: Ryan I have a great deal of respect for you and your opinions. I've invested a lot in Mike Holts DVD's, and you have played a major role in my career advancement....Thank You:smile:!

Anyone, not wanting to stay stationary, should dive in to Mike Holt's DVD's and/or catch him at a seminar. As for Ryan....I lost count of how many DVD's/Books he's contributed too.

 

[weressl]

I did not say that "ground fault" and "short circuit" were interchangeable. I said, essentially, that a "ground fault" was an example of a "short circuit." And I will stick with my statement that a connection between an ungrounded conductor and an EGC is a connection across the voltage source. True, it is a connection that uses long wires and not just a short jumper. But the definition of "short circuit" that I quoted from my dictionary does not make that distinction.

Charlie,

Do you consider the ground fault of an ungrounded system a short circuit?

 

[ryan_618]

Well Ryan_618....Obviously you don't know what your talking about!

Just Kidding:grin:....Just Kidding:grin: Ryan I have a great deal of respect for you and your opinions. I've invested a lot in Mike Holts DVD's, and you have played a major role in my career advancement....Thank You:smile:!

Anyone, not wanting to stay stationary, should dive in to Mike Holt's DVD's and/or catch him at a seminar. As for Ryan....I lost count of how many DVD's/Books he's contributed too.

Thanks for the compliments Daniel, that is very kind of you to say. I also enjoyed your input on one of the videos

 

[ibew441dc]

Fine then!!!

Fine then!!!

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.

Okay ...for all of the haters out there How about this definition....

Short Circuit-some times good, some times bad, usually bad, and could be all at the same time

FPN(1)- A Short Circuit is clear to those who want it to be, and not clear to those who pick apart terms with good intent, or not clear to those who are sleeping (they may wake immediately , not knowing what the explosion was)

FPN(2) One who debates the term may or may not be a Qualified Person (see Article 100)

 

[iwire]

Okay ...for all of the haters out there How about this definition....

I am not a hater, :smile: I just firmly believe that nothing should be added to the NEC at anytime which can not be shown to have a direct and positive effect on electrical safety.

Why not push for a definition of objectionable current, there is a term that is used in the NEC and does not have a common definition. :smile:

 

[weressl]

I am not a hater, :smile: I just firmly believe that nothing should be added to the NEC at anytime which can not be shown to have a direct and positive effect on electrical safety.

Why not push for a definition of objectionable current, there is a term that is used in the NEC and does not have a common definition. :smile:

I object!!!!!!

 

[George Stolz]

Okay ...for all of the haters out there

LOL

I take all my opinions from Bob, so blame him.

Actually, I agree with Bob's view to a large extent. In addition to electrical safety, I would push for clarity of existing requirements, even if they aren't related to safety. Some items are so golden to the CMPs they will not let them go, but they aren't clear. I try to clear those up with proposals, when I see them and I feel I can add some clarity. For example, the design requirements of 210.52.

You don't have to convince us, just the CMP. But if you could convince us (the tough crowd), you'd have a better chance of success.

 

[ibew441dc]

LOL

I take all my opinions from Bob, so blame him.

Actually, I agree with Bob's view to a large extent. In addition to electrical safety, I would push for clarity of existing requirements, even if they aren't related to safety. Some items are so golden to the CMPs they will not let them go, but they aren't clear. I try to clear those up with proposals, when I see them and I feel I can add some clarity. For example, the design requirements of 210.52.

You don't have to convince us, just the CMP. But if you could convince us (the tough crowd), you'd have a better chance of success.

Was the definition of Neutral Conductor safety related?.....If so how? IMO the term grounded conductor was perfectly clear...(right). The Code Panel only added it to correlate with the term used in the NEC. Everybody knew what is was.

As far as convincing everybody hereor the CMP, I am less concerned with that, then I am convincing myself that I do or do not fully understand a term based on facts or accepted interpretation. One thing I enjoy is my own opinion being challenged and welcome outside input (outside input...is that an oxymoron).

 

[don_resqcapt19]

Was the definition of Neutral Conductor safety related?.....If so how? IMO the term grounded conductor was perfectly clear...(right). The Code Panel only added it to correlate with the term used in the NEC. Everybody knew what is was.

It was a code application issue for derating. The word is used in the derating rule and it is not the same as a grounded conductor for that application. And no, everyone did not know what it was... at least not for the purposes of applying the code rules. Kind of like we all knew what a bathroom was before the code said we had to provide GFCI protection for the bathroom receptacles. I just don't see a code application rule that hinges on the definition of short circuit.

 

[ibew441dc]

It was a code application issue for derating. The word is used in the derating rule and it is not the same as a grounded conductor for that application. And no, everyone did not know what it was... at least not for the purposes of applying the code rules.

Your telling me the understanding of Neutral was not clear in (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.

I have stated my opinion and supported my logic many times on this thread. I just think Short Circuit should be added to correlate the use of the term throughout the code......

Maybe I'm barking up the wrong tree...... Maybe "McGraw-Hill Dictionary of Scientific and Technical Terms." needs to be modified to correlate with the term used throughout the NEC.......HMmmmmm:roll:

"McGraw-Hill Dictionary of Scientific and Technical Terms."
A low-resistance connection across a voltage source or between both sides of a circuit or line, usually accidental and usually resulting in excessive current flow that may cause damage."

 

[don_resqcapt19]

Your telling me the understanding of Neutral was not clear in (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.

I am not sure exacty where the defintion of neutral came from. I would have to go back and look at the ROPs and ROCs, but I do know that it took at least 3 code cycles to arrive a defintion that was accepted by the CMP.

There are code rule applications that hinge on knowing what a neutral is. I am not aware of any code rule applications that hinge on knowing what a short circuit is.

 

[ibew441dc]

I am not sure exacty where the defintion of neutral came from. I would have to go back and look at the ROPs and ROCs.

By all means go back and check.....the definition came from IEC influence and the IEEE definition of Neutral Point.

There are code rule applications that hinge on knowing what a neutral is. I am not aware of any code rule applications that hinge on knowing what a short circuit is.

Really.....

90.8(B) Number of Circuits in Enclosures.
It is elsewhere provided in this Code that the number of wires and circuits confined in a single enclosure be varyingly restricted. Limiting the number of circuits in a single enclosure minimizes the effects from a short circuit or ground fault in one circuit.

110.7 Wiring Integrity.
Completed wiring installations shall be free from short circuits, ground faults, or any connections to ground other than as required or permitted elsewhere in this Code.

240.4(A) Power Loss Hazard.
Conductor overload protection shall not be required where the interruption of the circuit would create a hazard, such as in a material-handling magnet circuit or fire pump circuit. Short-circuit protection shall be provided.

240.9 Thermal Devices.
Thermal relays and other devices not designed to open short circuits or ground faults shall not be used for the protection of conductors against overcurrent due to short circuits or ground faults, but the use of such devices shall be permitted to protect motor branch-circuit conductors from overload if protected in accordance with 430.40.

After absorbing input, opinion, and facts from multiple resources including, but not limited to forum members, professional references, and the NEC. I am more content with the way it stands now, but feel that it would still clear up the question as to exactly what defines a short circuit.

 

[George Stolz]

There are code rule applications that hinge on knowing what a neutral is. I am not aware of any code rule applications that hinge on knowing what a short circuit is.

Really.....

90.8(B) Number of Circuits in Enclosures.
It is elsewhere provided in this Code that the number of wires and circuits confined in a single enclosure be varyingly restricted. Limiting the number of circuits in a single enclosure minimizes the effects from a short circuit or ground fault in one circuit.

You realize that this section doesn't have any mandatory terms in it, so therefore is essentially meaningless filler in the NEC, right?

110.7 Wiring Integrity.
Completed wiring installations shall be free from short circuits, ground faults, or any connections to ground other than as required or permitted elsewhere in this Code.

...and you realize that they weighed short circuits and ground faults equally in that section, right?

240.4(A) Power Loss Hazard.
Conductor overload protection shall not be required where the interruption of the circuit would create a hazard, such as in a material-handling magnet circuit or fire pump circuit. Short-circuit protection shall be provided.

In this instance, I would argue that short circuit protection includes the standard ground fault protection provided by a normal circuit breaker. They can't say "ground fault protection" without meaning GFPE, no?

240.9 Thermal Devices.
Thermal relays and other devices not designed to open short circuits or ground faults shall not be used for the protection of conductors against overcurrent due to short circuits or ground faults, but the use of such devices shall be permitted to protect motor branch-circuit conductors from overload if protected in accordance with 430.40.

Again, short circuits weighed evenly with ground faults.

After absorbing input, opinion, and facts from multiple resources including, but not limited to forum members, professional references, and the NEC. I am more content with the way it stands now, but feel that it would still clear up the question as to exactly what defines a short circuit.

The last incarnation of your proposal still stated that a short was only between two ungrounded conductors, I believe, which I still disagree with. If you were to create a definition and try to sell it to the CMP, then I would say:

Short Circuit: An intentional or unintentional low-impedance connection between two insulated conductors.

I would say anything wrong other than that is a ground fault.