HV Transformer dude almost terminating himself and the house cat! - Page 1
Forum section: electronics / general

author: jpyeron
author_rank: Regular Contributor
timestamp: February 12, 2024, 12:52:56 am
content: Sigh

author: BlownUpCapacitor
author_rank: Frequent Contributor
timestamp: February 12, 2024, 05:49:50 am
content: He's really damn lucky to be still alive today. If a transformer gets excessively hot, something isn't right.And the video in that video where he shows a piece of sheet metal stuck in the ceiling... he was that close...All in all, glad he's fine.

author: Berni
author_rank: Super Contributor
timestamp: February 12, 2024, 06:31:34 am
content: I had no idea a potted transformer could explode THIS violently.Then again that is a LOT of potting around it. So guess it was strong enough to contain the vaporized gas coming off the burning enamel insulation up to a incredibly high pressure, then cracking and letting it all out. Looks like the iron laminations might have been helping hold it together too.These are the worst dangers where you don't even realize something so bad could happen.

author: PartialDischarge
author_rank: Super Contributor
timestamp: February 12, 2024, 08:17:18 am
content: I'd like to see the rating of this transformer, probably its a 100V measuring type which is typical for PLCs and he applied 240V. In any case this transformers should be installed with fuses.As for people talking about voids inside, maybe, but a production test for this transformers is a partial discharge test which would detect that defect easily.

author: PartialDischarge
author_rank: Super Contributor
timestamp: February 12, 2024, 08:32:31 am
content: I watched the video very quickly and can confirm this guy doesn't have any idea what he's doing.The first picture demonstrates that he strongly overdrove the primary. Then he admits he doesn't even know what the BIL is, assuming its the maximum output you can get. He says he got maybe 140kV but that it only rated for 125kV as per BIL. The BIL is insulation related not voltage at the output.In short, this guy burned the primary creating shorts in between the turns, thus increasing the current drawn by the transformer, creating internal gas and heating, thus the explosion.I can't believe people do this things without even reading a bit.

author: abeyer
author_rank: Frequent Contributor
timestamp: February 12, 2024, 10:17:34 am
content: Quote

author: Psi
author_rank: Super Contributor
timestamp: February 12, 2024, 11:18:13 am
content: Quote from: PartialDischarge on February 12, 2024, 08:32:31 ammeh, everyone does stupid things when young and when starting something new.Everyone starts somewhere and everyone starts without the required knowledge.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: February 12, 2024, 11:28:43 am
content: I'm not surprised a potted transformer can explode like this - it's tempting to assume a solid thing will just get hot and conduct heat to the outside, but at some point the rate of expansion wins.Something similar I've seen first-hand are aluminium-clad wirewound resistors, which have an element encapsulated in some kind of resin in an ali. extrusion. It's tempting to think that puttting these on a big heatsink will allow near-inifinte overload as the heat will get dumped into the ali.But what can happen is they blow one end of the resistor terminal out the end with substantial force - possibly trailing the unwound resistance wire behind it like a taser, which is fun if it happens to have mains voltage on it.

author: PartialDischarge
author_rank: Super Contributor
timestamp: February 12, 2024, 11:33:35 am
content: Quote from: Psi on February 12, 2024, 11:18:13 amI understand what you are saying, but you don't make "HV channel" out of it, and disregard warnings like the transformer getting hot, instrument transformers are epoxy made because they are not meant to get hot ever, they are for measuring, not for energy transmission.I don't think he even has a minimal electrical training, there is no excuse for this. If he were really interested he'd learn some concepts and he is not doing it.

author: MT
author_rank: Super Contributor
timestamp: February 12, 2024, 02:39:51 pm
content: Quote from: Psi on February 12, 2024, 11:18:13 amA dude who afterwards sits in a space monkey t-shirt trying to explain his stupidity shows he dont know what hes doing.

author: Haenk
author_rank: Super Contributor
timestamp: February 12, 2024, 04:22:06 pm
content: Quote from: Psi on February 12, 2024, 11:18:13 amWell, I did blow myself up as a kid. Still got some metal fragments in my left handSo yes, stupid things do certainly happen. I'm way more careful now. And I'm not doing explosives.

author: coppercone2
author_rank: Super Contributor
timestamp: February 16, 2024, 08:08:15 am
content: if you see how they do some hv transformers its in a big bin of oil with a lid that opens up on a hinge and its not really pressure sealed, just has a gasket around it that is sealed with the weight of the lid. I saw this before in rf transmitter. Nice way to manage pressure.maybe stick to oil filled basins rather then trying to use sealed tactical crapIMO he is a victim of 'OIL BAD' 'POTTING GOOD' mentality.You need to realize just because they made something that can be thrown into a wet damp manhole tunnel and installed by underpaid tossers (like literarly they will toss it) with zero plans for maintence does not make it good lab equipment as cool as it looks. Half this stuff is designed the way it is because its meant to be installed by the least possibly skilled worker in the fastest amount of time possible with zero maintence cost (and if you prevent maintence and require replacement then you gain money). it can be often done in a slightly more complicated way that requires some skills but brings major benefits to repairability and lack of explosions.And also that thing I bet was designed with the idea that its likely to go off in a isolated tunnel where no one is allowed to be if it is powered.

author: PartialDischarge
author_rank: Super Contributor
timestamp: February 16, 2024, 03:54:11 pm
content: Quote from: coppercone2 on February 16, 2024, 08:08:15 amI cannot believe what you are saying. You simply don't know what that transformer is and what happened.1) What happened is that this wannabe electrician connected the secondary as primary and overdrove it *continuously" by probably a factor of x5 over the nominal. Now let's change the whole industry and the standards so people like this don't get hurt LOL.2) That transformer is made for measurements not for energy transmission. They are designed for low burden. They do not need heat dissipation. Epoxy is the most reliable, 0 maintenance, long lifetime solution. They can be installed horizontal or vertical. They are installed by the tens of thousands in medium voltage switchgear to measure voltage (along others to measure current).Oil transformers have problems like risk of fires, humidity getting inside and can't be installed horizontally.I'm just scratching the surfaceQuoteIt is designed to be used with a fuse in the HV primary, so the secondary or primary never develop high pressures inside. Even if no fuses are used these transformers are very safe.Phase-Phase instrument transformers are designed to withstand 20% more of the nominal continuously.Even more, because a 3-phase system can have a ground fault and have ground shifted to a phase, phase-neutral instrument transformers could see the voltage increased by sqrt(3), so they are designed to withstand 90% more voltage as standard (thus the rating 1.9xUn/8h seen in many of these transformers)In short: There is a lot of science and human thinking as to the why of these casted transformers, and there is0science and human thinking in what that "Youtuber" did

author: mendip_discovery
author_rank: Super Contributor
timestamp: February 16, 2024, 06:51:14 pm
content: Photoinduction is another YTer that does some crazy stuff but be does seem to have some knowledge of the risks.Though I dont think the likes of ElctroBoom help with people remaining safe around electricity.

author: coppercone2
author_rank: Super Contributor
timestamp: February 16, 2024, 08:50:22 pm
content: Quote from: PartialDischarge on February 16, 2024, 03:54:11 pmWhy would I care about the industry selling potted crap. What I am saying is that being around a sealed transformer is convenient (for those scared of oil) but not safe. Big pressure vessels can go boom. The youtube comments were like "I never go past 200% overload". Hardly wisdom. Try never going above overload on a big sealed component. I see a buncha ghetto ass DIY guessing at a SOA curve with alot of figuring and ass scratching thrown in (construction worker shit). It looks like no one in the community actually uses the fucking thing to spec.I thought it was a transformer to conveniently power telemetry electronics off a hV line. If its a pure instrumentation transformer then any impedance less then 100kOhm = fail. Then its just 100% misuse.If its made for measurement then the load should never be anything that arcs too.

author: Bud
author_rank: Super Contributor
timestamp: February 16, 2024, 10:10:12 pm
content: Was it necessary to show his bleeding nose to the World? Fucking moron, they do everything to extract an extra buck.

author: tooki
author_rank: Super Contributor
timestamp: February 16, 2024, 10:33:55 pm
content: Quote from: coppercone2 on February 16, 2024, 08:08:15 amNah, he’s got other videos showing his oil-filled transformers, including performing maintenance on them in his bedroom. I’m sure his mom is delighted to clean transformer oil out of the carpet… 😂

author: coppercone2
author_rank: Super Contributor
timestamp: February 17, 2024, 12:56:24 am
content: probobly should stick to those because they might damage the ceiling but it won't throw big heavy chunks of dense plastic at you easilygranted that is only if you have a functional over temperature shutoff for the oil

author: shapirus
author_rank: Super Contributor
timestamp: February 17, 2024, 01:18:47 am
content: Quote from: Psi on February 12, 2024, 11:18:13 amYeah, but those on the smarter side tend to take some safety precautions. For example, when I was, I guess, 8 or 9, I asked my father: what will happen if you stick tweezers into the wall outlet? He replied: "a short". Well, as you can imagine, that's not the explanation you want to give to an inquisitive kid. Of course I wasn't satisfied and went on testing it myself. But I did know very well that electricity may be dangerous, so I used pliers with insulated handles (1000V rated -- and I did pay attention that this was well above the 220V mains voltage) to hold the tweezers. The fuses at that time were actual fuses -- a piece of wire that melts at a high enough current -- so there was enough time for the experiment to produce quite a spectacular bang before the fuse did its job.

author: schmitt trigger
author_rank: Super Contributor
timestamp: February 17, 2024, 01:53:49 am
content: This is what people do on YT to attract followers. Stupid on top of stupid.Many years ago, a young husband and wife had the brilliant idea to make a video, showing that a pair of thick books would stop a handgun bullet.You know where this is headed, correct? The husband held the pair of books close to his chest, the wife fired the gun…. And promptly killed him.The wife was arrested on charges of manslaughter and if I recall correctly, she was sentenced.She left a pair of little children parentless.

author: tooki
author_rank: Super Contributor
timestamp: February 17, 2024, 06:02:06 pm
content: Quote from: schmitt trigger on February 17, 2024, 01:53:49 amI’m not entirely certain he’s hamming it up for the views. He just strikes me as a teenage nerd with the stereotypical teenage boy sense of invincibility.The story of Monalisa Perez and Pedro Ruiz is quite sad really: the boyfriend (they weren’t married) was clearly a moron who had no idea how powerful a Desert Eagle was. (I didn’t, either, before this story came out. But then again I wasn’t trying to get someone to shoot one at me! For those who don’t know: it’s really fucking powerful.) The girlfriendreallydidn’t want to do it. But he kept nagging her about it forover a monthuntil she gave in. And even in the moments before pulling the trigger, she begged repeatedly to not do it. But he insisted. So she really didn’t want to do it, and she’s the one who has to live with the consequences. (She was sentenced to just 180 days in jail, followed by 10 years parole and a lifetime ban on holding firearms, so it seems to me that the courts understood the situation.)Because yeah, it turns out a single encyclopedia volume can’t stop a 50 caliber high-powered cartridge fired at point-blank range, no matter how many times you tell your GF that it’ll be fine…Oh, and their toddler was there and witnessed it.

author: Wolfgang
author_rank: Super Contributor
timestamp: February 17, 2024, 06:48:18 pm
content: A failed Darwin award, but it was closeMaybe you learn something about transformer ratings before your next attempts. Or maybe not

author: PwrElectronics
author_rank: Regular Contributor
timestamp: February 18, 2024, 02:37:25 am
content: QuoteI had that happen with one of those one time. I was working on a 48v 3ph inverter project. I was suspecting some shoot through problem and to protect the unit while troubleshooting I had put one of those type resistors in series with the power supply to limit the current.A bit later, I had forgot it was there and was sitting hunched over with my back to the power supply (and that resistor) and that thing let go with a sound like a gun shot. It was amoment for sure. And yes, the blown out end trailed a uncoiled string of wire.

author: Andy Chee
author_rank: Super Contributor
timestamp: February 18, 2024, 05:25:36 am
content: Many moons ago as a work experience kid in a film developing shop (remember those!) I took home a few boxes laden with discarded disposable camera shells.I extracted about a couple dozen capacitors and connected them in parallel to a single flash unit from one disposable shell. After several minutes of charging I triggered the flash. Made the loudest BOOM I've heard in my entire life, and temporarily lost some hearing in one ear. Vaporised the Xenon flash tube bulb of course, only the legs of the bulb remained with their PCB connecting wires.Never knew so much energy could be released from a single AA battery!

author: schmitt trigger
author_rank: Super Contributor
timestamp: February 24, 2024, 08:45:40 pm
content: Thanks Tooki, for filling the (quite large) gaps in my story.

author: Black Phoenix
author_rank: Super Contributor
timestamp: February 26, 2024, 12:04:00 pm
content: Quote from: Andy Chee on February 18, 2024, 05:25:36 amI had 2 spots in my hand from a Nikon charged camera capacitor I discharged by inadvertently touching both contacts in the PCB while handling it. Looks like believing the owner of the camera that he didn't use it for a while (so assuming that it was discharged) was the wrong thing to do.Lesson learned, now I take caps as if they were a "loaded gun" and always proceed to discharge them before attempting any kind of handling of a naked PCB.Heck still to this day when I think about it it still tingles where it "bitten".