Accidental contact with 120 volts 

At high current.

Totally agree. When people say it's current that kills, it's misleading while true at the same time. You cannot have current with out voltage in a circuit. A bit like when people say thats a torquey engine. That means nothing. But what it's implying is it's able to provide power not far off idle. Power = RPM x Torque or work over time. What kills is current yes but that cannot happen without the PD to push it. The greater the voltage the more current through a given resistance. Brushing your hair with a comb can generate 10,000 volts with very little current. Putting a spanner across your car battery can allow thousand of amps but you can put your fingers across the terminals and nothing happens. Your spanner has a lot lower resistance than your hand for electricity.

I have a mig welder that tops out at about 20v.

@@sonacphotos except I can soak my hands in salt water then grab the electrodes of said battery and I will be just fine. Just because it delivers high amperage means nothing. Just like I can hold onto 100kv at Pico amp level and will be just fine. Must have the correct balance of both.

@@P25AES be careful with that milli amps can stop a heart.

Always test the wires with the back of your hand...

Hey man I'm happy for you and your family! Hard work should pay off buddy. Glad everything worked out for you and no one got hurt! Stay safe man.

Loving your videos, Aaron . So interesting to see and learn what you guys do on a daily basis out in the field.

Thanks for the videos going through my apprenticeship it helps see videos like this and what to pay attention for!

I forgot to ask about the game changer for storm work? Is it a drone? We have a drone department as well as an arrangement for helicopter time. They save time for covering ground in thick overgrown right of ways or steep treacherous slopes. Let it be a surprise? I’ll wait for your next video after your settled in? E-mail me if you would like a house warming gift? Do you have a registry? Let me know? Congratulations again to you & your family!

Thanks John much appreciated! Always a pleasure hearing from you! No registery here, could really use a fence tho! Lol jk (my dog hates this whole leash thing). Hoping to put one in soon! I'll let ya in on the new tool on e-mail 🤫🤫

lol my buddy used to weld up cheater rigs for stuck bolts with a 6v motorcycle battery DC aint no joke

A 12v automotive battery can dump literal hundreds of amps for quite a few seconds. A starter can draw upwards of 450 amps when they spin up and start turning the engine. And thats not a direct short, I can only imagine the amount of amps a 12V battery could dump in a direct short situation.

I did maintenance on 24 v plant that's 2v cells each a total of 24 lead acid batteries connected in series parallel.you saw,what happened with just 1 lead acid battery just think if you shorted 24 of them ?

My neighbor was working on a 12v marine battery when the tool he was holding shorted with enough energy to melt his wedding ring. His finger looked like a cooked hot dog.

@@robertschemonia5617 Back when I was a smart ass teenager I wondered just how quickly a cloths hanger wire would heat up if you touch it to both poles of a 12 battery. I can tell you I INSTANTLY let go. And I never tried it again. The two burns were just surface, but quite painful.

Same thing happened in my city, I get the pressures to do it live but it's just not worth the risk. • On 3 February 2015, four electricians opened the CFS access cover to inspect the damaged fuse. While opening the cover, one of the separated end-caps was dislodged. • The fuse end-cap sank in the oil tank and made contact between one of the “live” 11kV busbars and the earthed tank at the bottom of the CFS. This created an electrical short circuit and an electric arc, a catastrophic explosion and the expulsion of hot oil which ignited into a fireball inside the switchroom. • The four electricians all received horrific burns from the explosion and subsequent oil-fuelled fire. They all managed to exit the HV switchroom. One died at the scene. Another was transported to hospital but died later that day. The two survivors spent months in hospital receiving treatment for severe burns.www.sbs.com.au/news/wa-shopping-centre-blast-kills-two-men

try our downtown 120/208 ring with 12 transformers in parallel on it. they don't make breakers that can handle that kind of fault current.

Sounds like he experienced an arc flash. That will ruin or end a life.

Well said AJ! 💯🍻 Cheers and thanks!

Shut up

Well that escalated quickly 🤣

Best part about the job is going home!

a good movie to watch I think is life on the line :)

He's speaking relative to what they often work with.

totally valid, but that’s a terrible analogy.

Wow. I would of thought it would of glowed cherry red until it fell apart since it's direct current.

@@lorenguaylg I wasn't there I saw the photos during an electrical safety course when I was hired by the phone company, but the remnants were blobs of what was molten steel and copper. The bus bars are solid copper, typically 1/2" by 10" and there are multiple solid copper bars. These all run to the battery banks. Each cell produces 2 volts. There are 24 in series. Each office will have multiple banks. of batteries. Now for the cells. They measure about 2' x 2' x 2' each. The cables that connect each cell to the next are solid copper 1" in diameter. The + and - (positive from cell 1, negative from cell 24) connect to the overhead bus bars which lead to each bank of batteries. The small office I work out of has 6 sets of batteries. (as I said each set of batteries has 24 cells.) Thats 144 large cells connected in series / parallel and under dead short we are talking 48 volts at 10's of thousands of amps. From the description of what happened at this exchange, a much larger exchange than the local one I work out of there would have been even more batteries, a worker working on something overhead dropped a large wrench that was long enough that it landed directly on top of the bus bars and created a dead short. Did I mention that these batteries are floating at 52 volts from a power supply. Well they are. The office I work out of has multiple rectifiers. One is running 1200 amps, and the others 900, 800 and 600 amps respectively. That is 3500 amps at 52VDC just from the rectifiers and then there is the reserve of fully charged lead calcium cells. The description told from someone that was there was a bang and a huge arc flash explosion that vaporized the wrench in an instant and blew a big chunk out of the bus bar. We were shown graphic pictures of the damage. Nobody was injured but the worker that was about 25 feet above it did have to go change his pants after the incident. Fortunately there was nobody working below when it rained molten copper and steel. No, the batteries are NOT fused. The equipment powered is. The bus bars bring the battery supply into the fuse boxes.

@@12voltvids I believe I with that amount of current available

And yet 48 volts would barely be noticed by a human. Funny how that works. Education is key, no amount of ppe can protect an imbecile.

@@jasincolegrove4798 fact is most accidents happen with the most experienced workers. When you have done the job long enough it becomes almost automatic and you can easily lose your train of thought because you have done this same job 1000 times before.

Where my friend lives the local power company replaced all the poles AND got rid of the secondary lines between poles by putting a transformer at every pole instead of every 3rd pole. I guess that reduces the chances of a cross between the primary and secondary.

Lol no flex intended 🍻

Definitely broke 1000! Yes, very lucky there wasn't even a slight sunburn. Cheers!

If he was close to the transformer, maybe 6kA.

Glad everyone is ok . Congratulations on the new house. Love from new York.

@@jfbeam Probably not that high if it was residential. I believe a 50kVA pole pig with 5% impedance has an available fault current around 2400 amps. Residential breakers usually have 10kAIC rating.

@@rampagerick I might be wrong, but if the transformer is 50kVA, @ 5% imp, wouldn't the fault current be close to 4200A? It's been a while since I had to do the calculation, so, like I said, I might be wrong.

Also true with every circuit in the house that's not GFCI protected (most of them aren't). Overcurrent circuit breakers are there to protect the equipment from overheating, not the user from getting shocked. Though to be fair they will trip in this type of overcurrent arc flash condition. But they won't help in an electrocution.

@@chrisbauer1925 I am seriously considering replacing every circuit breaker in my house that feeds an outlet with GFCI breakers. What say you?

@@flagmichael GFCIs are more important where there is water easily present, but it will improve safety to have them everywhere. Generally unnecessary, but still theoretically safer! It's also important to note tht a GFCI can only detect a line to ground current, but will still ignore an electrocution in the case of getting between live and neutral, though that is fairly rare to happen accidentally.

@@flagmichael Usually you don't die from touching 110 in your house. Actually, mostly you don't die from touching it.

@@chrisbauer1925 I've touched the hot and neutral so many times over the years, not on purpose but grabbing a plug to move it to get a board over it or just rushing, and I know that distinct feel of our 110 60hz power. I can feel the cycles and paint a picture of them as I feel them. 110 isn't really that big of a worry as the wire size in your house is also the big limiting factor, as well as the breaker. Do you know the difference between electrocution and an electric shock? You only get electrocuted once and you don't live to tell the story. You can get shocked many times and live to tell the story. Now 220, thats something you gotta be a bit more careful with because it's gonna hurt. More wire, higher amperage breaker and twice the potential to get you than 110.

It's more in the few kA range

Yep output is normally in the range of 16-30VDC or 24VAc on aluminum

In UK regs require all new installations to have residual current devices over all circuits in the consumer unit. If using any mains equipment outdoors all my outside waterproof power points have extra rcd protection. Years ago I cut thru hedge clipper cable...everything went off consumer side...hedge clipper stopped working.,.no drama.

Was he bare foot and soaking wet? Otherwise that's pretty damn hard to do.

@@russtomas4461 Great question, I don't know the details. I am sure that OSHA will be involved. Sounds like worked for a mechanical contractor, which doesn't mean much though

@@rchuyck Not what I mean. You can hold on to the hot side of 120 volts and dance in puddles all day long. Let's assume worst case scenario here. He is not wearing water proof boots and they soak. The current must still travel through 20M ohms of resistance to get to ground. If his body is dry from head to foot, he is not going to fry.

@@robinmyman Um in North America all out door sockets are required to have GFCI/RCD protection so that should have not happened

S T A R You know the drill Stop. Think Act. Review 3 way conversation

I used to keep a Klein screwdriver in my tool grip. Had been undoing L1 when debris blew and shorted the screwdriver to The other phase. It left a corkscrew blast around the shaft of the screw driver as the insulation burnt. It happened so quick that the motion of the screwdriver before I pulled back from the panel created the spiral. It was a great reminder that no matter how safe you think you are and how experienced you are that things can still happen

and now you wear the PPE for every job?

@@philhoward4466 I was wearing my PPE that day, every day before, and every day after. So your question comes across as cocky, ignorant, and condescending. PPE has nothing to do with the events that unfolded. If I took an extra second to think about what I was doing and a better way to go about it, it wouldn’t have happened

Did he get a refund from the lifetime warrantee on the tool :)

No we dont, we use 240V in the UK and mainland Europe use 220V, there was a european union harmonisation of the voltages so that europe came up to 230V and the UK dropped to 230V, but the UK didnt really drop the voltage. Also if your electrician friend had that happen to his screwdriver, ask him what did he do with the cutout fuse? domestic dwellings are fused at 60amps unless its fitted with storage heaters and then its 80amps.

We also use 240v here in the USA. It's used for higher power loads like dryers and hot water heaters. The 120 volts hot to neutral here is derived from a grounded center tap on the 240V winding of the transformer feeding the residence. 240 volt loads are connected to the 2 hots, but no single wire is greater than 120v from ground.

@@stiggyness1976 the Voltages did not change. The tolerances changed to accommodate 220 to 240 :-)

@@andrewwhite1793 I have measured the mains voltage many times throughout my life in NL, last decade it has always been 230 volts +/- a volt or so.

Thankfully the safety culture is becoming more and more accepted. It can be a tough juggle while maintaining efficient cost effective service but more and more companies are seeing the value making safety a top priority !

@@Bobsdecline Being in the union helps that as well with us. I am in the IBEW here, and Safety is a big big thing with us. There are paragraphs about items that protect us.

It wasn't hardened any more once it started glowing :)

All steel has about the same melting point, within 100 degrees or so. Hardened ot not it would have melted in the same amount of time. Almost instantly at about 2600f to 2700f degrees.

Technically the hardness and toughness of the steel isn't really a factor for melting/vaporization.

@@wouldntyouliketoknow9891 Yeah "technically" harder steels are made of a different mix and some mixes take more heat to melt than others. If you're going through the process of hardening steel, chances are its gonna be a better, higher quality blend with materials that take a bit more heat to melt.

Contact welding (spot) runs a 'mere' 2-3v at the electrodes, all that means is it can't reach out and grab you the way line voltages can

Thanks Chuck!

1200 Amps is just the normal operational current. worry about the fault current which can be over 200 kA! touch it with your fingers and you get a little 0.048 A whack. touch two lines with your wrench and you better be wearing the right PPE.

@@tripplefives1402 100A is for relatively lightweight jobs or when don't mind needing 10+ passes to fill a large weld. Here's an example of ~1000A welding: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-j61ezBX-EyA.html

It's important to note that your scenario can and will cause events similar to those shown in this video, it doesn't inherently make it for humans. It all comes back down to Ohm's Law how much current something will draw, no matter what kind of power supply you have. Most conductive materials make it very easy to push high amounts of current (theoretically) because they have resistances very very low. The human body does not have a low resistance, in fact quite high comparatively. I=35/.00000003 = 1 GAmp. I=35/1100 = .032 amps, and that's the low end of skin resistance; while wet and close together. Higher estimates will be around 80,000. Mostly harmless at that voltage. That's why some people get annoyed when they claim that it's "current that kills", because you can't have sufficient current without sufficient voltage. When skin resistance is relatively known, there will be a general minimum voltage where there starts to be a risk of dangerous electrical shock. Obviously it's the real world and these armchair calculations are going to be of little use if you happen to come across some edge case and scorch your arm, ending up with third degree burns, because you brushed up against something that someone told you wasn't dangerous in the middle of a rainstorm and you thought you could be fine. So just always use PPE and take proper precautions.

Very true! I think this video perhaps better summarizes why the saying “it’s not the voltage that kills you, it’s the amps” is misleading (though technically true): ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-8xONZcBJh5A.html

@@tripplefives1402 you’ve clearly never seen a ships hull welded.

That's what he says.

Even 5Volts are enough. Look at refining Aluminum.

Just watch the YT videos of peeps using 2V with 2.2 kA to melt steel in seconds.

@@magicmulder I start my car using a pair of double A batteries

Yep, hitting the incomer to a house can be energetic. Not sure about short circuit/ground fault currents on average in the US/Canada, but here in the UK, we have to assume anything up to 16,000A (16kA) at the service head (which is where the supplier's cable terminates into a main fuse block then on to the meter). That can and does vaporize things. And the arc flash can seriously mess with your complexion

@@TheChipmunk2008 Yes, I think we were darn lucky to be wearing heavy leather work gloves.

@@TheChipmunk2008 US residential is commonly rated to 10kA. (about 2x what a service short would likely pull, and far more than any load out of the panel could do.)

@@jfbeam If it matters I'm in and older part of the city where my house service was 60 amps. Was upgrading to 100 amps because they wouldn't let me go beyond that. (was going to put in 120).

Ionized

Down to earth.. hurhurhur

Hired a contractor to replace light switches. He couldn't get voltage. Pulled out my non contact tester and the hot lines were still hot. Come to find out. Him pulling the box out he pulled the neutral out of the upstream box.

I dislike the go/no-go NCVs, they're hard to get an affirmation on. I have one with a proportional chirp, and you can hear the difference between the line sine and square wave of fluorescent drivers, and the amplitude tells the story. It's a crazy squeal off an HF LED driver, and it's good for double checking old-as-balls light switches that can have substantial leakshorts from 90 years of flash-sputter. Not enough to light up even a 5w lamp, but I don't want to tempt fate

I've actually got quite a bit of footage on this already, I've just never edited anything together yet. I'll try n get something up soon

P=V^2/R would be more applicable since it is the current passing through the high resistance of your body that is literally cooking you.

In this case there is not much to limit could have been hundreds of amps going through that drill now if their was some kind of resistive load in series or current limiter that would bring the max current to say 100 ma would have been nothing more than a few little sparks

It has its place, properly used to explain why low voltages can be dangerous and high voltages can be safe. A feather dropped off the Empire State won't hurt a bit. A car an inch above your torso would kill you.

5 volts times 400 amps is 2,000 watts of heat, just like a 20 amp breaker at 110! basically same power level!

@@superchuck3259 It was actaully 640 amps, two parallel 320a supplies. Keep in mind the nominal voltage of an AC arc welder is about 25 volts and look what that can do with 100 amps behind it.

@@superchuck3259 640A _continuous_ rated. They all have output smoothing caps that can generate significant short circuit currents.

Yep, in that case electric shock isn't the concern so much as the arc flash and burns.

640mA 🤨

I mean when it's an open circuit he is right about no amps. LoL but yeah I was face palming.

No amps until ya touch it! ⚡⚡

Would have been a non issue if he didnt have the ring on, very stupid to be wearing jewelry when working on things like that. Its true that human skin wont conduct 24 volts and he would be safe, but the ring is another story.... could see it heating up in an instant and burning through his finger.

@@Clapxiomatic Insult on top on injury - he was charged for having his wedding band on.

@@johnnytarponds9292 I got my wedding ring between a car battery and a grounded wrench - it got fearsomely hot in an instant.

@@flagmichael LOL I bet!

Unless you are sweaty, they going to get burned!

Yes, you are absolutely right! 💯. While expecting to be questioned about that, I went into an explaning this in the video... I decided to cut that whole part as it diverted my intent of the video and left more even more questions unanswered. While there's a big difference, there is still certainly a hazard, and this better demonstrates the capability of low voltage. In this specific circumstance that arc flash would likely have been the most concerning imo ✌️🍻

@@superchuck3259 YES, this. 120-240 can easily grab you and make you not alive in short order if you're hot and sweaty on a summer's day or stuck in an attic or similar. People say 'oh stop being a sissy and man up' or similar. I'd rather be a sissy with PPE than a new project for the undertaker without it, thanks :)

True. But the difference is 1A (human -- actually closer to .1A; currently measuring my sweaty paws @ 700k) vs. ~4kA for a dead short. (depending on line length, and transformer impedance) Humans tend to want to get away from power, tools tend to weld themselves to it. I have no idea what the ratings are for the PoCo cut-out, but they will blow if you short the secondary side. (been there, done that, blacked out a neighborhood.) [ V*I, or I*squared(R), means the human won't heat up nearly as fast. If you've ever "cooked" a hot dog, or pickle, with one of those novelty electric jobs, you should have an idea how quick a human would be seriously injured. ]

@@jfbeam the human is dead either way. That's the thing they miss

I once unplugged a computer as a kid and my fingers crossed the contacts and I felt a contraction wave all the way up to my shoulder! It was the craziest thing ever and very freaky, I was like 8 years old. I was shocked but since I was ok I was kinda fascinated with the experience.

@@joshuagavaghan224 I actually got shocked a few times while working for the same company. We had this damned slushie machine that provided the base for some of our frozen drinks. I got a few noticeable zings off the machine. Issue was there was a ground fault at the plug it was connected to. The first few were grounding out to a nearby donut rack that we would use as balance to climb a little step stool to fill up the Machine. Got it fixed. Then the store underwent renovation. Then every time it was shocking people was when the plug got jostled in the new plug because we kept drink powder on top of the plug

Even extremely low voltage can be lethal is contact is directly across a vital organs. Like you said, if the voltage is high enough to have conductivity through you, it can be lethal. I think some consider lower voltages "less lethal" because they can be more forgiving. That's definitely not an excuse to treat it any differently, however if you were to have 69kv across your body vs 120v, the chance of survival would be much much greater with 120v.

The way they taught it to me is that voltage has the potential to send more current through a given resistance and it's the current that kills you - but don't get careless with lower voltages either because if you got good conductivity and / or the current goes through your heart , even LV can do you in - like if you have dry gloves a few hundred might not kill , but if I got barefeet in the rain or mist and I get a left hand on 50V and current goes through my heart to ground through my leg it might be all she wrote.

If your body is a fixed resistance, 7200V/120V = 60, so a 7200V line will push 60 times more current than your wall voltage which can be far more lethal.

Or if you have a low voltage and low impedance path. Story I was told 40 years ago, when we all tested our skin resistance with the old Simpson analog meters, which is safe enough, was one guy in, I believe ET school in the Navy, got the bright idea to test his resistance beneath the skin and inserted the probes in each hand. Well, the skin has a fair resistance, but the salty blood is a very good conductor and he killed himself with a AA battery, definitely not more than a 9v battery.

@@jkbrown5496 I've heard that story though, not sure if it's a myth or not. I wish I had a better idea of how resistive blood is, though it must be pretty low because whenever I measure my skin resistance it doesn't matter what two points I pick, even if the probes are 1 inch apart or on totally opposite ends of the body it reads pretty much the same, indicating below the skin is far more conductive.

I dropped a spanner onto a car battery once, only stopped once it melted and sagged in the middle...

@@gordonrichardson2972 Yeah lead acid batteries were chosen for car starting duty precisely because of their (for the size) relatively low internal resistance and thus high current output. not something I like messing with tbh. I tend to use short circuit protected power supplies for my extra low voltage electronics work for that very reason.

Thanks!

Thanks Topper! Cheers!

Watching from Northern Maine, USA btw!!