Article 100 Definition Addition! SHORT CIRCUIT

[ibew441dc]

Every wonder what the definition of a SHORT CIRCUIT was in the NEC?(I sure do)

Article 100-Part I and II should include an authoritative definition of the commonly used (and easily mis-used term).

Okay.....to avoid this part........I know, I know....see 90.1(C).blah, blah , blah...a trained person should know what a short circuit is.True, but based on what reference?, I challenge you to google it, check different dictionary's, IEEE, maybe NEMA even? My point is .....the different sources imply different things.

......A trained person should respect the fact that we all have to be accountable to an authority.........in the 'Electrical Installation World', that authority is NFPA 70(NEC).

The NEC states pretty clearly what an Overcurrent is and subdivides it into 3 categories.:smileand this is only one example)

Overcurrent. Any current in excess of the rated current of equipment or the ampacity of a conductor. It may result from overload, short circuit, or ground fault.

Overload is in Article 100, Ground Fault is in 250,..... so where is SHORT CIRCUIT?

I suggest the NEC add Short Circuit, with an appropriate definition in Article 100, Parts I and II. Some might be saying......Well then make a proposal! I have never done it and wouldn't mind even if someone else made it.

Here is my suggestion....

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.

FPN (1): A Short circuit is not a Ground Fault (see Article 250.2 Definitions)
FPN (2): A Short Circuit is not an intentional or unintentional electrical conducting connection between a grounded conductor and an equipment grounding conductor.(see 250.6 Objectional Current)

 

[charlie b]

I think the phrase "short circuit" is best left to the realm of commonly used industry terms. At my desk, for example, I have a copy of the "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."

Also, please note that a short can be between two ungrounded conductors, or between an ungrounded and a grounded, or between an ungrounded and an EGC. A "ground fault," as defined in article 250, is but one example of a "short circuit," in that it is a low-resistance connection across the voltage source.

By the way, it will be another two years and change before they will start accepting proposals for revisions to the 2011 NEC. :wink:

 

[480sparky]

.........By the way, it will be another two years and change before they will start accepting proposals for revisions to the 2011 NEC. :wink:

Don't you mean for the 2014? Any proposals for the 2011 were due last November.

 

[don_resqcapt19]

Don't you mean for the 2014? Any proposals for the 2011 were due last November.

You both said the same thing using differing words. Charlie said revisions to the 2011 code, you said revisions for the 2014 code. They both mean the same thing.

 

[480sparky]

You both said the same thing using differing words. Charlie said revisions to the 2011 code, you said revisions for the 2014 code. They both mean the same thing.

To-Mah-Toe.....Tuh-Ma-Toe!:grin:

 

[ibew441dc]

At my desk, for example, I have a copy of the "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."

My point exactly,..... Charlie, have you ever compared definitions with other respected references? Also your reference makes no implication that a "hot to ground connection is a short circuit"((1)across a voltage source?(2)both sides of a circuit or line)

Also, please note that a short can be between two ungrounded conductors, or between an ungrounded and a grounded, or between an ungrounded and an EGC. A "ground fault," as defined in article 250, is but one example of a "short circuit," in that it is a low-resistance connection across the voltage source.

I disagree respectfully disagree with you interpretation.:smile:
If this were the case then why do you suspect they are used in a manner that is not meant to be interchangeable, but rather describe a specific electrical connection through out the NEC.

By the way, it will be another two years and change before they will start accepting proposals for revisions to the 2011 NEC. :wink:[/QUOTE]

Then I got some time:grin:

 

[ibew441dc]

Whhhuuuuuuuaaaatttt??????

Whhhuuuuuuuaaaatttt??????

I disagree respectfully disagree with you interpretation.:smile:

I meant.....I respectfully disagree with your interpretation:grin:.............. I did'nt catch the mistake in time

 

[charlie b]

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 b]

To-Mah-Toe.....Tuh-Ma-Toe!:grin:

Let's call the whole thing off!

 

[jim dungar]

I said, essentially, that a "ground fault" was an example of a "short circuit."

I disagree, kind of.
Typically ground faults are not low resistance faults like short circuits are (if they were we would not need special GF protection on 480Y services). It is also possible to have a ground fault between a grounded and a grounding conductor.

Of course if part of the current path includes the grounding conductor, the fault is by definition a 'ground fault'.

 

[ibew441dc]

False

False

It is also possible to have a ground fault between a grounded and a grounding conductor.

Jim,:smile:
The above statement is false.

The definition of a Ground Fault is clear in regards to the conductors involved.

250.2
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.

The connection of an unintended Grounded Conductor to an EGC is Objectional Current. (see 250.6) Not a Short Circuit and not a Ground Fault.

 

[jim dungar]

The definition of a Ground Fault is clear in regards to the conductors involved....

The connection of an unintended Grounded Conductor to an EGC is Objectional Current. (see 250.6) Not a Short Circuit and not a Ground Fault.

I am not debating the definition of ground fault in 250.2 , however it is intended to be used only within Article 250 (see the scope of definitions in Article 100). It is more restrictive than that generally used by the electrical industry. The listing/performance requirements for Ground Fault Protective devices, required in 210, 215, and 230, absolutely do not ignore possible 'grounded to grounding' conductor fault paths. I was trying to say that not all ground faults are short circuits.

 

[ibew441dc]

Originally Posted by jim dungar
It is also possible to have a ground fault between a grounded and a grounding conductor.

Jim is the above an accurate statement?

Originally Posted by ibew441dc
The definition of a Ground Fault is clear in regards to the conductors involved....
The connection of an unintended Grounded Conductor to an EGC is Objectional Current. (see 250.6) Not a Short Circuit and not a Ground Fault.

I am not debating the definition of ground fault in 250.2 , however it is intended to be used only within Article 250 (see the scope of definitions in Article 100).

Article 100
Scope.
.......Other definitions are included in the article in which they are used but may be referenced in Article 100......

It is not intended that definitions in specific sections only apply to that section.......It just means that they are only mentioned there.

It is more restrictive than that generally used by the electrical industry.

Of course it is........That's part of the problem, especially in the field. All of us say things from time to time that we thought all along were true, only to find the opposite. An art that must be mastered by all of us is our understanding,translation and delivery of important electrical terms. I like to be held accountable for the comments I make (Believe me ...I got egg on my face all the time:grin. Again the very reason why I posted this thread.:smile:

 

[George Stolz]

I don't really see it as a significant addition to the NEC, but if it's important to you I'd suggest writing a comment to the 2011 NEC when the time comes, to a relevant proposal. You might be able to sweak your language in at the comment stage.

 

[ibew441dc]

IMO-Short Circuit similar misuse as Grounding.....

IMO-Short Circuit similar misuse as Grounding.....

I don't really see it as a significant addition to the NEC......

I do.....Short Circuit is used loosely............just like Grounding was for years(grounding/bonding terms have come along way,but still have some tweaking to do).

It's bad enough when two educated electricians and/or engineers have a discussion about something and are not speaking the same language, basing arguments on definitions that all do not share, merely assuming the other looks to the same authoritative text.

Short Circuit is used all over the NEC ,and in a number of places, the NEC makes it clear that Short Circuit,Ground Fault, and Objectionable Current are different.

 

[ibew441dc]

IEEE-Short Circuit (Definition )

IEEE-Short Circuit (Definition )

What is the definition of Short Circuit in the eyes of IEEE?

 

[Pierre C Belarge]

Short Circuit:
Makes a lot of noise and generally scares some people. :grin:

 

[cadpoint]

What is the definition of Short Circuit in the eyes of IEEE?

I've read here that www.merriam-webster.com is the NFPA dictionary of record, choice and used as a point of response.


short-circuit
&
Short circuit - one being a transition Verb and the other a Noun.

Good Luck with your verbage and pro's composing that for 2011 comment and
your 2014 submittal....

 

[ibew441dc]

My point of view........(it can be fuzzy at best sometimes)

My point of view........(it can be fuzzy at best sometimes)

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.

Article 100,Overcurrent. Any current in excess of the rated current of equipment or the ampacity of a conductor. It may result from overload, short circuit, or ground fault.

Article 100,Overload. Operation of equipment in excess of normal, full-load rating, or of a conductor in excess of rated ampacity that, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload.

HMMMMM??
:roll:............. OR......... pen or pencil .........either of the two are writing utensils....but they different . short circuit and ground fault are both faults but they are not the same

430.52 Rating or Setting for Individual Motor Circuit.
(A) General. The motor branch-circuit short-circuit and ground-fault protective device shall comply with 430.52(B) and either 430.52(C) or (D), as applicable.

240.92(C)(1) Short-Circuit and Ground-Fault Protection. The conductors shall be protected from short-circuit and ground-fault conditions by complying with one of the following conditions:

HMMMMMM?:roll:.....AND pens and pencils both write but they are not the same..........short circuit and ground fault are both faults but they are not the same

 

[George Stolz]

I do.....Short Circuit is used loosely............just like Grounding was for years(grounding/bonding terms have come along way,but still have some tweaking to do).

It's bad enough when two educated electricians and/or engineers have a discussion about something and are not speaking the same language, basing arguments on definitions that all do not share, merely assuming the other looks to the same authoritative text.

I'm kinda lost here. Has there been such a conversation lately? :-?

I thought short circuit was a fairly universal term, I didn't know there were two relevant ways of looking at it.

Short Circuit: A fault between two conductors that cause a properly sized OCPD to open, which does not include the Equipment Grounding Conductor of a circuit.