Not to start yet another war between us but just for clarification on the "arc-fault" situation. How if the NEC was followed did this even happen? Stuff like this is supposed to be enclosed in the correct type of panel/box not on an open panel. Or are you saying it created enough plasma to both destroy the cover of the panel and do the other damage? I think there is more to this than meets the eye.

 

Stuff like this is supposed to be enclosed in the correct type of panel/box not on an open panel.

But it was properly enclosed! Moreover the entire substation was both planned and installed by highly trained and experienced licensed professionals -- Top of the line equipment and personnel all the way!

How if the NEC was followed did this even happen?

As is the case with all standards/codes/best practice/regulations, etc... While the NEC, IEC, etc, generally represent 'solid bases' - they are neither perfect nor anything approaching a guarantee! -- Hence my insistence upon exclusive employment of automated and/or RC operation of energized installations...

are you saying it created enough plasma to both destroy the cover of the panel and do the other damage?

The cabinets, 'tulips', busbars and switchgear proper are now, for the most part, a several molecules' thick 'coating' on (what remains of) the surrounding Portland infrastructure (à la 'gettering' on the inner surface of an electron tube). Further to that, three solid (as opposed to 'cinder-block') concrete partitions (18" thickness each) were reduced to rubble, and the office area (60' distant) was set ablaze secondary to intense IR emanating from the 'fireball' -- all and all a lovely day out

I think there is more to this than meets the eye.

Quite possibly! -- Based upon his inspection and my CC 'footage', the adjuster estimates the MAFC (i.e. maximum available fault current) at > 500kA (i.e. > 240MJ per second) - which being fully five times my estimate -- In any event there's no question of compliance and --far and away-- most importantly, no deaths or injuries! -- Merely a temporary (albeit highly annoying) inconvenience

Not to start yet another war between us

No worry of that! For my part (and, I daresay, @Aleph(0)'s as well) I apologize should I seem to have 'slammed' OSHA and/or the electrical standards authorities! -- Heaven knows the 'built environment' is a much safer place for their existence!

even though it's totally different procedure it still proves my point abt never, ever racking in breakers on energized bus! Cuz ppl who think it's totally safe as long as breakers are open are living and sometimes DYING in fool's paradise! Cuz tiniest arc just from surface moisture or insect or whatever can definitely ionize enough air to get all three phases into it causing catastrophic metal arc at full MAFC! So what a lot of ppl just don't get is biggest hazard of high energy electrical equipment isn't shock! It's arc fault!

Abso-freeking-lutely!

@Aleph(0) many sincere thanks/congratulations on your recognition of the fact that my motives in 'sharing my troubles' in this matter owe to a more altruistic cause than mere whining - To wit: a reminder to our readers that --while implementation of all applicable safeguards is imperative-- the best safeguard is distance from the hazard! (especially ---by way of preemption of objection from all you laser and supernova/GRB 'fans' out there--- where said hazard is of an 'uncollimated' nature)

unions

Aleph! Please eschew commentary upon the merits of organized labour! Good, bad or indifferent! -- Such fairly teeters on the doorstep of politics!

Edited by @Aleph(0) 2 replace obscure abbreviation

That was a very thoughtful thing 4u2do!

Very best regards
HP

 

@shortbus

In preparation for composition of the EHT indicator 'micro-tutorial' I have 'anchored' your d'Arsonval mounting scheme to my blog (for direct reference [i.e. 'linking'] from said tutorial) --- Please verify that said entry meets with your approval...

I thought later after posting about something that could make the locator and meter clamp even easier for people. If you guys want I can show a sketch of that too.

Inasmuch as all reader contributions are (or, rather, will be) resident upon --and solely linked from-- my blog, corrections, updates, etc... are welcome at any time including post-publication - As a single change to the appropriate blog entry will be immediately reflected everywhere said resource is linked --- All of which is to say - No pressure! We're grateful for contributions at the contributor's convenience!

Very best regards and many sincere thanks!
HP

PS -- @cmartinez @jpanhalt @The Electrician @theodoravain et al --- Please rest assured that your suggestions/alternative approaches, etc... will receive similar 'treatment' during composition of the appropriate tutorials (e.g, the LVPSU 'TIHIDI', LOPT driver decoupling inductor fabrication, etc...) -- (As will @shortbus' core-puller upon our return to the LOPT-Repurpose tutorial)

Please rest assured that I spend several hours per week reviewing this 'long and winding thread' such that no viable idea is overlooked! -- That said, should anyone feel we've forgotten or failed to grant a 'fair hearing' to any idea, advice or 'info' (including --while by no means limited to-- alternative approaches, component/materials sourceability, 'calling out' perceived over-estimation of readers' financial resources, access to instruments/facilities etc...) I implore you to tell us about it!

 

Hypatia's Protege, Here are the alternative ways of making the locator, Faraday shield, and clamp. They are to be used with the other drawings dimensions. They are easier to make only by the fact that the cutouts can be made without doing it all on the interior only. And the shield is cut on the corners instead of drilling mounting holes.

 

Hola!

@Jazz2C -- Did/could you capture images of the movement (so mounted) for upload?

Good thought, HP but I lent it to Belnair (sp?) until I can replace their megger that died with my MDO! But I can totally photo-document attaching another meter to a panel @shortbus style!
Hey @shortbus! I totally agree that your idea of the horseshoe shaped spacer and clamp will make it easier!

OBTW @Hypatia's Protege, I have a photographic surprise to pluck you from the depths of your "electrical depression" with memories of better times and thoughts of better days to come! In the words of your often recited "ancient broadcaster": stay tuned!

Take care and count your blessings my dearest friend!

 

View attachment 170993 Hypatia's Protege, Here are the alternative ways of making the locator, Faraday shield, and clamp. They are to be used with the other drawings dimensions. They are easier to make only by the fact that the cutouts can be made without doing it all on the interior only. And the shield is cut on the corners instead of drilling mounting holes.

Indeed! -- All of that in addition to the observation that a pair of 'snips', 'bypass cutters' or a hand-held 'moto-tool' are less cumbersome (and costly) than a fly-cutter-equipped milling machine!

Please be advised that I have incorporated your latest drafts to the appropriate blog entry -- again I request that you please review same with an eye to 'link integrity', etc... --- Many sincere thanks!

I can totally photo-document attaching another meter to a panel @shortbus style!

Thank you!

OBTW @Hypatia's Protege, I have a photographic surprise to pluck you from the depths of your "electrical depression"

Despondency? No! Annoyance on to rage? Perhaps!

As regards 'surprises' -- I stand with the theme of the retro-advert linked below:

To wit: "The best surprise is no surprise!"

In the words of your often recited "ancient broadcaster"

---EMPHASIS ADDED---

I can't imagine why not - howbeit I very much doubt a deceased albatross 'round my neck will go far in 'elevating' my spirits...

Hey @Jazz2C -- Seriously, while I genuinely appreciate your concern, you may rest assured that I'm not 'bummed' -- merely peeved -- and that greatly mitigated by the fact that no-one was injured nor even endangered!

my dearest friend!

@Jazz2C! --- That will be quite enough of that! -- Sentimental codswallop is all of unappreciated and always off-topic despite this thread's location!

Best regards
HP

 

Sentimental codswallop is all of unappreciated and always off-topic despite this thread's location!

Rightly so... but can you blame the poor fella?

 

Hypatia's Protege, Blog post is fine with me. Glad I could help out.

 

Rightly so... but can you blame the poor fella?

While I greatly appreciate sincere expression of friendship and/or gratitude (where due) I am obliged to point up the fact that the nature of my over 12 year's involvement in @Jazz2C's life has been that of a 'mentor' and, indeed, in loco parentis in every moral, emotional and practical sense of the phrase! -- Hence my especially vehement objection to his frequent expressions of highly inappropriate 'amative sentiment' toward myself --- Paint me 'old fashioned' howbeit it is my strongly held opinion that there are certain feelings that no gentleman entertains (let alone expresses) Re: a 'mum figure'! -- To be clear, while, owing to our non-consanguinity, it would be unfair to class JC's feelings as 'degenerate' --- 'uncouth verging upon dissolute' would seem to fit the proverbial 'bill' quite nicely!

But I can totally photo-document attaching another meter to a panel @shortbus style!

Again thank you! But please eschew 'vertical letterbox format' photography/cinematography...K?

Hypatia's Protege, Blog post is fine with me. Glad I could help out.

Many sincere thanks!

Very best regards
HP

 

While I greatly appreciate sincere expression of friendship and/or gratitude (where due) I am obliged to point up the fact that the nature of my over 12 year's involvement in @Jazz2C's life has been that of a 'mentor' and, indeed, in loco parentis in every moral, emotional and practical sense of the phrase! -- Hence my especially vehement objection to his frequent expressions of highly inappropriate 'amative sentiment' toward myself --- Paint me 'old fashioned' howbeit it is my strongly held opinion that there are certain feelings that no gentleman entertains (let alone expresses) Re: a 'mum figure'! -- To be clear, while, owing to our non-consanguinity, it would be unfair to class JC's feelings as 'degenerate' --- 'uncouth verging upon dissolute' would seem to fit the proverbial 'bill' quite nicely!


Again thank you! But please eschew 'vertical letterbox format' photography/cinematography...K?


Many sincere thanks!

Very best regards
HP

On my part, your rightful objection to a former apprentice's un-curbed enthusiasm is not only understood, but also undeniably approved. It clearly shows that you've been bestowed with a generous amount of wisdom and common sense.

But then again, what would you say if your suitor's unrequited love manifested itself in the purest of forms, such as Gimli's unconditional devotion to Galadriel? :

‘Gimli Glóin’s son, have you your axe ready?'

'Nay, lord,’ said Gimli, 'but I can speedily fetch it, if there be need.'

'You shall judge,’ said Éomer. 'For there are certain rash words concerning the Lady in the Golden Wood that lie still between us. And now I have seen her with my eyes.'

'Well, lord,’ said Gimli, 'and what say you now?'

'Alas!’ said Éomer. 'I will not say that she is the fairest lady that lives.'

'Then I must go for my axe,’ said Gimli.

'But first I will plead this excuse,’ said Éomer. 'Had I seen her in other company, I would have said all that you could wish. But now I will put Queen Arwen Evenstar first, and I am ready to do battle on my own part with any who deny me. Shall I call for my sword?'

Then Gimli bowed low. 'Nay, you are excused for my part, lord,’ he said. 'You have chosen the Evening; but my love is given to the Morning.’

 

From the past explanations of the Hp/Jazz interactions, I was thinking more along the lines of -

 

Jeez! Tolkien through (UGG!) Van Halen?! --- Whatever this thread's shortcomings 'want of eclecticism' 'ain't it'!

But then again, what would you say if your suitor's unrequited love manifested itself in the purest of forms, such as Gimli's unconditional devotion to Galadriel? :

1) Please be advised that @Jazz2C is in no way, shape or form my 'suitor'!

2) I would certainly find the 'species' of Quixotic hero-worship (depicted in the excerpt from Tolkien quoted in your post) neigh-on as troubling as @Jazz2C's inappropriate sentiments toward myself...

But hey @cmartinez don't despair! -- Noting that (per canon) Galadriel is Elrond's mother-in-law - taken with the fact that Elrond is, quite literally, 'older than the hills' under which Gimli's folk delve -- The excerpt certainly maintains the age difference aspect of the issue!

From the past explanations of the Hp/Jazz interactions, I was thinking more along the lines of -

To be clear -- @Jazz2C is by no means 'gigolo' nor, come to that, any manner of 'leech'...

Hey, gents here 'Tis:
JC's relationship to myself is entirely describable as what is quaintly termed a 'ward' --- Granting that said term is a bit 'long in the tooth' and with slightly different meaning [here in] the US -- You might accurately regard him as my (informally) adopted son --- Hope this clears up any misapprehension!

Very best regards
HP

 

accurately regard him as my (informally) adopted son

On behalf of Aleph, I need to ask, is he in the will? Sorry couldn't help my self.

 

On behalf of Aleph, I need to ask, is he in the will?

Shortbus, JC and I are totally like Bro and Sis since young age so we'd definitely be vry civilized vultures if HP's luck runs out playing with electricity!

Now being totally serious, I'm independently _wealthy_ and JC will be as soon as he stops being _professional student_ So our futures are totally secure thanx 2 HP cuz it's like old saying! Instead of giving us free meal she taught us to _fish_ so we can feed ourselves for lifetime!


Anyhow @Hypatia's Protege, just 2 let U know If you start EHT METER tutorial next week you'll totally have time to finish b4 I'm back on regular schedule!

 

If you start EHT METER tutorial next week you'll totally have time to finish b4 I'm back on regular schedule!

Very well then -- I've seen myself clear to begin the 'tihidi' the week beginning March 10 (which being one week later than you suggested howbeit a solid time-frame!) FWIW - I'll 'open' with an overview of the instrument (completed as per original plans) inclusive of images.

@shortbus Please know that your suggested (and, indeed, highly preferred) d'Arsonval-movement mounting technique will be strongly recommended and conspicuously linked in the overview! --- Then discussed in detail upon our arrival at the applicable 'chapter'...

FWIW My rationale for beginning with said original plans/images owes entirely to the unfortunate fact that construction of the prototype was completed prior to receipt of @shortbus' suggestions --- That said - improved mounting of the d'Arsonval unit represents the sole deviation from the original plans

To all interested parties: Please be advised that @shortbus' d'Arsonval-to-cabinet mounting technique --among other advantages-- enables use of a wide variety of indicator forms -- Please rest assured that the project does not require a bezel/frame style movement (à la that shown in the preliminary photos)

Best regards
HP

 

HP I see what ur trying to do by putting meter on raised platform to avoid glare from acoustic insulation panels but I say chart is also less than optimal background cuz of contrast issues (so for example ribs on left resistor housing basically blend in with color of land area on chart). Anyhow I'm not b!tching just trying 2 help out!

 

I say chart is also less than optimal background cuz of contrast issues (so for example ribs on left resistor housing basically blend in with color of land area on chart).

While I see (npi) your point --- Inasmuch as said features are, nonetheless, discernible on the left 'tower' and plainly visible on the right - taken with the fact that both 'towers' are of identical construction it would seem little enough ambiguity is to be apprehended in said regard? -- Then too the accompanying images all of which will appear in the 'overview' (to be published on this thread later this week) leave nothing to the imagination...

@Aleph(0) while I genuinely appreciate your thoughtfulness in taking a moment for proofing -- I must ask you to please check that posts are in 'public view' prior to publicly linking images therefrom! For reasons of safety and maintenance of (something bearing vague resemblance to) 'pedagogical integrity' I have no desire to encourage "precocious" readers' attempted construction of these projects sans context!

Cases in point:

1) Owing to 'camera angle' the image linked in your post fails to reveal the PTFE 'ion migration barrier' intervening the towers, absolute spacing of the towers, etc... --- The intent of said image is solely illustration of tower-to-midline approach/symmetry --- it is not intended to be viewed 'in isolation', as it were...

2) Although the 'first installment' is merely an overview, certain safety of life & property disclaimers are obligatory on moral grounds (at least)! --- Not the least of which being insistence upon use of proper PPE, maintenance of personal distance from energized apparatus and --in all cases-- the inadvisability of application to high energy/power systems ('high power' in this case meaning maximum available power > 100kW without regard to OCP interrupters, etc... [note that interrupters are not current limiters! --- They are with finite response times and, not uncommonly, fail altogether])! Please note that PPE ---and especially distance--- save lives/prevent injuries -- while the energy/power constraints limit property damage/loss when 'stuff' happens...

Hey @Aleph(0) --- You will please forgive my (in your case) 'preaching to the choir' Re: safety considerations - One must be mindful that public posts --no matter how 'addressed'-- are just that - public!

3) The image shows the original Faraday shielding frame sans reference to @shortbus' improved technique which being greatly preferred in nearly all cases!

But to your 'central' point -- Considering the large amount of imaging attending this effort - I begin to see the merit of arranging a small 'studio' to said end --- On my word! I will consider it - but not at cost of further delay!

//////////////////
Note to readers/builders: Fair warning! - I'm gonna get real 'boring' on the subject of safety! -- This includes zero tolerance of readers evincing lackadaisical attitudes in said regard! --- To understand my stance on this point you need merely consider the stakes:



'Nuff said!

Best regards
HP

 

But to your 'central' point -- Considering the large amount of imaging attending this effort - I begin to see the merit of arranging a small 'studio' to said end --- On my word! I will consider it - but not at cost of further delay!

HP I say all u need is like a few different colored pieces of _tag board_ for solid backgrounds

you need merely consider the stakes:

'Nuff said!

HP I say impression from piccy of AF accident is more like _standing rib roast_ than steaks

Now here's important disclaimer! Being familiar with site HP linked image from I can definitely say _organic debris_ in pic is either remains of just cadaver or test dummy! So ur not seeing human being die! Also IMO if it's cadaver there's still no disrespect for the dead cuz after all it was totally their choice to donate their body after death!

Also for ppl saying pic is in poor taste cuz _it's too disturbing_ here's all I can say:

◊I totally envy sheltered, happy life u must be living and I mean that sincerely! But I also say you need 2 grow up and face hard fact that human body is vry delicate and totally destructible by everyday phenomena! Cuz understanding that on like _intuitive level_ is basis of safety!

◊Pic is supposed to be disturbing to ppl complacent abt electrical safety! That's why HP posted it! So it's sad and vry dangerous fact that the word _safety_ puts most ppl to sleep! So it's like HP said she's just reminding you what's at stake! Definitely NOT trying 2 make u afraid of electricity! So for analogy think on all energy (not just electrical energy) as _Genie in bottle_ which can and will do ANYTHING you ask! So it's vry important to know its language so you know what ur asking! When u think on it, that's what's at core of all aspects (not just safety) of science and technology! ◊Science: Which is learning language of _nature_ ◊Technology/engineering: Which is formulating _request_ ◊Ethics: Which is careful consideration of consequences. And only then issuing _command_!

So don't blame electricity if you thought you were saying _let's open this feeder_ but were actually saying: _Turn me into a crispy critter and spread my ashes on the four winds! Pronto!_

So anyhow I think it's basically impossible to wake complacent ppl up abt safety But I totally agree with @Hypatia's Protege that we have to try! So I'm going 2b very boring on that subject too as anybody can definitely tell just from this post!

 

@Aleph(0), @theodoravain, @Jazz2C

Please proof the annotated images at the blog entries linked below ASAP (Your prompt attention to this matter would be greatly appreciated! -- I'd really like to publish the overview no later than late Sunday/Early Monday!):

https://forum.allaboutcircuits.com/blog/eht-indicator-images-continued.1516/
https://forum.allaboutcircuits.com/blog/eht_indicator-images-continued.1512/

All interested parties -- Please have a look at the following schematics with an eye to detection of any drafting errors -- with special attention to the 'equivalent circuits'):

Circuit proper

Equivalent circuits

Many heartfelt thanks!
HP

 

@Aleph(0), @theodoravain, @Jazz2C

Please proof the annotated images at the blog entries linked below ASAP

HP here's main areas for improvement I can see:

◊I say u need 2 show more detail of what ur calling _mast steps_ so ppl can understand their function is just to physically support and also electrically connect to _towers_ Also plz show underside of chassis so ppl can see mast steps are bolted down cuz otherwise they'll think they're just glued to chassis! HP now I've got to say something! Maritime analogy of _mast steps_ is totally apt cuz I can't think of anything they're more analogous to! But maybe u should keep analogy consistent by calling resistor housings _masts_ instead of towers?

◊Plz show more detail of PTFE _septum_ and its slotted CPVC mounting guides.

◊Now here's just possible problem: If I wasn't already acquainted with project I say transition from external view to internal view might be confusing. So I say u should also post image of cover by itself after removal from chassis! For better perspective u could show it with barrier attached so ppl will know septum is attached just to cover!

◊HP u are prolly planing to but just in case plz disclaim that _Mini Fed connector_ is just name u use to describe plug and well connectors u designed for project! Cuz otherwise ppl could get wrong idea thinking it's related to proper _Federal Connector_ meeting IEC standards and like that!

So for other readers, whole point is even though it totally works (by which I mean prevents arcing and excessive corona) to 150kV+ since it has no safety certification at all it isn't tested under _varying conditions_ or for _unanticipated failure modes_ and like that! So that's not problem if u follow HP's safety rules during operation! We just don't want to give false impression that project meets industry safety standards! You stay safe by keeping distance and using common sense abt dress of leads and max available fault POWER (not just current!) of supply! Also plz remember that distance is vry important even for vry low current cuz strike by just 5uA arc (so 1/2W at 100kV) could definitely produce enough heat to scar cornea! So it's like HP says: HV and radiological safety is mostly distance, distance, distance! And a guaranteed method of remotely shutting down HV PSU!

All interested parties -- Please have a look at the following schematics

HP all I can add 2 that is to tell ppl that meter protector is actually single component with function of bilateral OVP and parallel-equivalent capacitance!

So for ppl who want to build it with zeners and cap u need vry low leakage in operating range! Cuz diode leakage isn't linear (which means u can't just include it as part of shunt resistance)! Anyhow _protector_ is optional part but it can definitely prevent damaging meter movement during overvoltage event! Also shunt cap filters out noise and ripple which can cause _blurry needle syndrome_ Just so u know 100uA-FS D'arsonval meters are vry fragile But still totally _bullet proof_ compared to electronic meters near EHT equipment!