Intermittent Faults - Definition

Definition of intermittent

1. : coming and going at intervals : not continuous <intermittent rain>; also : occasional<intermittent trips abroad>

intermittently

adverb

Good Luck

Google elementary electricity, or Electricity for Dummies.

Thank you for that link, Rixter, I have wanted such clarification for years, Thank You So Much!

Cheers,

Geoff Thomas

Are you incapable of searching for the years long clarification yourself?

Why are you posting Anonymously?

What do you need this information for?

? talking to me?

Are you the OP?

If yes, yes!!

It is all rather confusing when posters do that.

Have to agree completely.

It does not help them at all, or us!!

Just look at reply #2 for an explanation of why someone would do that. If no good response comes, they can stay anonymous. I've considered it when I think I have a question that would make me look a bit weak in my current field.

Response #2 is a perfectly legitimate response to an elementary, 6 part question that is easily answered by a childishly simple search!

The Dummies publications are legitimate publications!

The OP is too lazy to look for themselves and wants the forum to do their homework for them.

Go do their work and don't criticize a reasonable answer.

I never said the OP didn't deserve it - just that folks will consider this when asking a question if they think their question might be a bit rudimentary, and resort to the "Anonymous" alias. Just an explanation of the most probable reason OP's do that.

As I said to Andy - I've considered it for some questions. Never did it - but did consider it.

Anonymous posting should be banned.

If a member can't own up to the fact that it may be an elementary question, then posting anonymously immediately says "homework" or "lazy" to most. Even Anons who admit it a simple question are usually not flamed.

I've asked some dumb questions and given some really dumb answers but I owned every one of them.

Yeah well...I've said enough things on this site that I figure at least a couple of the customer's engineers I deal with during a skid process checkout have figured out who is behind that "Phys" alias, as well as anyone from my home county, if one is on this site. I know one of our IT guys has figured it out. That is why I've considered doing the "Anonymous" thing. Don't want to look too weak to them. I assume there must be others, in a similar position, so it is good to have access to that Anonymous thing just in case.

I agree entirely, own your posts fully!! Well put!

You are right!!

Lynn's post was fully justified, I (sadly) did not give it the weight that it justly deserves, my failure, not his!!

Perhaps our OP should alter his avatar to "Lookfarther!"... Just a thought!!

I was not the OP, I simply thanked Rixter for his contribution, subsequently, what a great to do about nothing..

You really got it all mixed up with your badly written posts, didn't you?

Have you worked out why now?

If not, I can demonstrate for you why, its very easy.....

again Andy, your dog picture should have a much bigger much redder nose.

To help you to understand where you are making your mistakes, I have put together, just as I offered to, a list of the Posts in question.

I wonder if you will take the time to find out where you went wrong by reading through? Your follow-on post will probably tell us all.....

With regard to the colour of the nose of a Weimaraner, I have added some videos.....

Enjoy!!!

1) Anonymous Poster Post #0

What is meant by Intermittent faults? How do I visualize these terms "arcing", "restriking" or "vibrating" faults in ungrounded system against the bolted faults?
I know the term "restriking" in circuit breaker current breaking. How do i connect this term with a ground faults in ungrounded systems?
When a fault occurs in a ungrounded system and if the circuit breaker interrupts it, the "restriking" voltage which flows across the circuit breaker to the fault is called "restriking fault"? Is my understanding right?

What is arcing or vibrating fault?

2) Lookfar Post #4 in reply to #3

Thank you for that link, Rixter, I have wanted such clarification for years, Thank You So Much!

Cheers,

Geoff Thomas

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3) Andy Germany Post #5 (answering OP, no one else!)

Why are you posting Anonymously?

What do you need this information for?

4) Lookfar Post #6 answer Post #5

? talking to me?

5) Andy Germany Post #7 answering Post #6

Are you the OP?

If yes, yes!!

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6) PWSlack Post#8 answering post #7

It is all rather confusing when posters do that.

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7) Lookfar Post #9 answering post #7

Certainly not! and I did not post anonymously, it is your old nemesis Geoff Thomas who was so right and you were so wrong about batteries, Inverters etc, but who cares now, - we move on.

I liked the definition, so many definitions are obscure.

(His saying I find very inappropriate for someone who instantly reacts so badly!!! It is:-)
Let's try and think clearly when looking at information and only allow emotions when weighing up options.

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8) Andy Germany post #10 answering Post #8

Have to agree completely. It does not help them at all, or us!!

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9) Andy Germany Post #11 answering post #9

If we here are as unhelpful as you appear to believe, why post here anyway? Last resort. In this life, you have to believe who you want to believe, and accept the circumstances when you guess wrong!!!As you appear to have confused even yourself with the way you posted, take a long hard look in the mirror maybe?And do keep taking the tablets.....

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10) Lookfar Post # 21 answering #18

I was not the OP, I simply thanked Rixter for his contribution, subsequently, what a great to do about nothing..

__________________
Let's try and think clearly when looking at information and only allow emotions when weighing up options.

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( Lookfar appears to not have understood post #7 at all. He then completely ignores post #8 from PWS. Also other posts about anonymous and or confusing postings!)

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11) Andy Germany Post #22 answering post #21.

You really got it all mixed up with your badly written posts, didn't you?Have you worked out why now?If not, I can demonstrate for you why, its very easy.....

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12) Apology from REAL OP at last in Post #23

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13)Lookfar Post #23 answering post #22

again Andy, your dog picture should have a much bigger much redder nose.

__________________
Let's try and think clearly when looking at information and only allow emotions when weighing up options.

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To which I can only reply “the same as yours?” Because such muddled, rude and inaccurate thinking on the part of a member like Lookfar, can sure only be attributed the demon alcohol! and my dog is not allowed any!!!

As a person who has owned several Weimaraners, and shown them with some success too, I can assure him that her nose is exactly the colour it should be!! The camera flash and/or CR4 might have changed it slightly......its not red, even at Christmas....

Living in the country where Weimaraners were first “bred”, and knowing over a great many years literally hundreds of them, I think I can speak with some knowledge on the subject…..

Quite recently, we took 22 Weimarners, of all three types, on a 10 Km hike through the local forest, it was breathtaking!! Only one small fight between two Alpha males, right at the end....

For those of you unaware of what we are discussing, please watch the following videos, None of which are of any of my dogs!

Please observe the colour of the noses! Do you notice just how “RED” they all are?:-

https://www.youtube.com/watch?v=c988cnx9-KA

https://www.youtube.com/watch?v=9xHbf5coFzc

https://www.youtube.com/watch?v=rBdoZrjES7I

Other than the person concerned cannot speak German and mispronounces the German words and names, this is a good general video of Weimaraners:-

https://www.youtube.com/watch?v=6ifSudReeuM

(For those interested, an "a" in German has the same sound as "ar" in English, in "farm" for instance. A "w" has the same sound as a "v" in English, such as in "very"..... So the name sounds more like "Vi-mar-Rarn-er" when said correctly! My phonetic spelling is nowhere near perfect, but close enough for Government work I feel!!)

Sorry, I don't have the time to answer nonsensical emails, particularly assertions on character, supposedly wrong emails from the past which time has proved you dead wrong, so criticisms deriving from same are dead wrong also, but you can't argue with old engineers, they're hard wired to be always right, particularly when they are wrong.

YOU ANSWERED EXACTLY AS EXPECTED!!!

You wrote:-

"I don't have the time to answer nonsensical emails"

BUT YOU HAVE ANSWERED! WHY THEN?

Remember:- "Better to remain silent and be thought a fool than to speak out and remove all doubt."

Abraham Lincoln

You wrote:-

"particularly assertions on character, supposedly wrong emails from the past which time has proved you dead wrong"

WHEN? and WHERE? I TOLD THE TRUTH, THEN AND NOW! YOU SIMPLY DON'T WANT TO ANSWER IT!! I ANSWERED YOUR RUDE POST IN THE SAME STYLE.

A STYLE THAT YOU CANNOT HANDLE IT APPEARS, WHEN ITS COMING BACK AT YOU.

WHY MAY YOU BE RUDE TO ME AND I NOT TO YOU BACK, MAY I ASK?

You wrote (rudely again!):-

"so criticisms deriving from same are dead wrong also, but you can't argue with old engineers, they're hard wired to be always right, particularly when they are wrong."

SO ARE YOU AN ENGINEER AT ALL? APPARENTLY NOT, ACCORDING TO SOME OF YOUR POSTS!!

BUT IF YOUNG, YOU STILL HAVE A MASSIVE AMOUNT TO LEARN.

I BET MYSELF THAT YOU ARE AN AMATEUR DIYER, YOUNG ACCORDING TO YOUR POSTS....

As "Methinks thou protesteth too much!!!" (Misquoted from Shakespeare's MacBeth if I remember correctly!)

Also, if you did not read my last post fully (as you say), you would not have posted as you did, as you would not know the content! Which you obviously do!!

You are simply not as clever as you believe you are!

Remember, I said before, WE would know if you read it or not IF YOU ANSWERED AND HOW, you did answer and we now know HOW!!!

In the UK we might say, "all mouth and trousers!" (But you may not fully understand that!) Its far better and friendlier than using the "W****R" word I find.....I am sure you would agree!

Oh, by the way, I can honestly say that you do not have a clue about batteries either!!! You proved that some time ago if I remember correctly....but it was amusing for us at the time, so you are completely forgiven for that error...... Fun and amusing is always good!

But you brought it up again in a recent post, so I am answering it again! That was your choice!! This is mine!!!

A REALLY IMPORTANT "LIFE" TIP FOR YOU, (your choice if you take it on or not of course!) WHAT HAPPENED IN THE PAST IS LONG GONE........learn from it and make progress in and for the future.....

I wish you a very Merry Christmas and a Happy New Year.

See you in the new year on a friendlier note I trust....as I don't hold grudges long, as many here can testify to.....I'm far too old and wise for that!!!

This is one of the stranger questions at CR4

1) Why does "repetitive restrikes" mean?

Multiple times. Repeats. Not necessarily periodic.

2) Why does the arc disappears instead of appearing continuously?3) Why does it appear sometimes and it dont sometimes?

Once an arc starts, the air ionizes, so it's more conductive, so the arc is more sustainable.

The arc could "corrode" at the contact points, thus stopping the arc. The distance that the arc travels could change. Air currents could "blow" it out.

An arc creates heat, and most materials expand. Let's take a crack in an insulator. Let's say it's "cold" or normal temperature and the crack is the smallest. Contaminants such as oil, water vapor cause a "more conductive path". An arc starts. The insulator heats up. The arc stops.

It cools. the arc stops.

The fields strenth is greater when the points of contact are smaller. More Volts/Meter so to speak. Air has an ionization potential that very dependent on cross-sectional area, temperature, spacing, composition. It's really not a static condition like say a spark plug.

Even a controlled electronic circuit element such as a spark gap which can be used in high voltage oscillators degrades over time. There was an arc lamp at work that required a 40 kV pulse to start and 22 v and 40 A to run. As the number of ignitions increased, the starting became intermittant, there's erosion of the electrodes at every spark and it wears non-uniformly.

Here https://en.tdk.eu/inf/120/ds/ssg5x1x0270.pdf is a datasheet for a spark gap. Note that the very first ignition has a higher breakdown and it's rated for 100,000 ignitions. The first might be due to oxides on the electrode which are burned away during the first ignition after 24 hours of darkness.

See this https://en.wikipedia.org/wiki/Corona_discharge article on Corona Discharge.

https://en.wikipedia.org/wiki/Electric_arc

https://en.wikipedia.org/wiki/Arc_flash

"intermittent" faults are everywhere. One of the simpler ones is a loose connection. These are usually thermal or mechanical (such as vibration or orientation) in nature. Arcing is a more complex phenomena.

At the outset, I apologise to the forum for my anonymity and the vague question. I feel guilty after reading all the answers. Yes, I'm a student, but this is not my homework. I have been to a plant last week as a part of Industrial visit on our course.
There in a 35kV switchgear, through transparent window of the cubicle, I saw continuous arc between a terminal and the cubicle enclosure. Everyone could listen to noise of the arc then. It ran on the surface of insulator and flied to the enclosure.
The arc was disappeared when power supply was turned OFF, of course. But the arc did not come back when power was turned ON again.

But, after some time, the arc together with noise came back and continued.
The Operators there repeated the procedure some times, but result was different like;

1) Sometimes the arc appear immediately when turned ON.
2) Sometimes the arc appear after some time after turning ON.
3) Sometimes the arc did not come back.
Then I heard the operator saying "Intermittent Fault". Then I started to study about this, that's why the above questions.
During my readings through several articles in Internet, I see the terms "repetitive restrikes", multiple re-ignitions.
1) Why does "repetitive restrikes" mean?
2) Why does the arc disappears instead of appearing continuously?
3) Why does it appear sometimes and it dont sometimes?
Arcing Fault:
An arcing fault is the flow of current through the air between phase conductors or phase conductors and neutral or ground.
Loose connection, Dust, water or other contamination accumulate and cause insulation breakdown.
Intermittent Fault:
Earlier I was thinking Intermittent fault as the one which could happen only incase of accidents, or weather conditions forcing a phase conductor to touch another phase or ground.
I admit I have to read more about it. Once again sorry for the inconvenience caused.

You need someone with expertise in insulators, maybe there is one here, I really don't know.

An overly humid atmosphere (we have no idea where you are!!) and a tiny, almost invisible crack or burn in the insulator, could do exactly what you are seeing, for example.

But I am no expert on this subject, though I did know one 40 years ago in the UK, no contact since many years...he is probably long gone...

But for the right person, I am sure that it won't be a problem, he will simply know.

Still many important details missing plus a photo or two!! Get working!!

Why didn't you pose that question immediately while you were at the plant last week as a part of Industrial visit on your course?

That would seem an ideal time to secure an understanding of all the various faults witnessed by the group.

<unsubscribes, shaking head in disbelief>