How bad you get zapped before a GFCI trips 

"When the GFCI detects an inbalace, it launches the button across the room to warn you."

Funny story: When I was ~16 I had a class about electricity and my teacher set up a demo very similar to this one. He believed that it was good to let kids feel what AC feels like. (Reasonably safe ofc, with isolation transformers etc etc.) I asked if I could opt out, which he really didn't want to allow, until I showed him the scars on my hands from where I grabbed an uncovered extension cord I had forgotten to unplug while repairing it. I explained I got the 2 marks on my thumb and index finger from where the full 230V went trough. Although we have whole house GFCI protection here in Belgium (300mA or 30mA depending on situation), since I wasn't making any contact with ground and my hand was (luckily) not low enough resistance to trip the 20A breakers instant shutoff, it "coocked" my hand while I was frantically swinging my left arm at the switch on my lab bench's power switch. In some ways I was lucky, because I was not touching any earth, so none of the current went up my arm. I usually don't even remember the scars are there, except when I get really dry hands and the "pull" a bit or get itchy. Or of course when someone makes a video about electrocutions :) Now all of my lab sockets have been behind an additional 6A 10mA RCBO. They might be expensive, but for 50€ you really can't play around. Also: A second hand E-Stop button can be quite cheap and is much easier to hit than a power socket switch, but any switch is better than no switch at all. Because I can assure you: You cannot let go.

Big Clive and Retroboom will both be very proud of you about now.

I had a shock from 400VAC hand to hand when working on a dodgy site and it almost killed me. The unqualified electrician had bottom fed a set of breakers (the busbar was on top), I switched off the breaker and removed the wires below and got shocked. I broke protocol by not testing for zero potential. Since that day I have never broken protocol again.

dude, this is the best video. I've wanted to see this since I was a kid....other kids did too, but they didn't get to live this long. Patience is a virtue.

I’m glad this was a full video, and not …. a short :)

A safety video so extremely safe children should avert their eyes.

The sharper increase is the skin resistance breaking down as the current finds a direct path under the skin tissue. There is plenty of iron to maintain a good current afterwards. I remember the 80's as well as the 70's. It hurts.

My sophomore circuits professor told us that the most dangerous case is a path through the heart, such as from one hand to another. He said that 60 joules through the heart was deadly. Hence the rule that you work on AC with one hand in the back pocket.

I remember reaching into a light socket to change the bulb back in my youth, only to not find a bulb, and sticking my hand straight into the connectors. That got me one hell of a zap.

I think with an open hand, the reflex is to fold the elbow, so I agree that you were doing it very safely. It's really people getting caught by surprise while gripping a tool that at a huge risk. I heard another danger is falling from the steptool/ladder when getting zapped by surprise.

I like the idea of testing osha standards on certain things like safe voltage/currents. Especially when they’re higher than we’d expect. My kind of safety video.

I wonder if your wife watches these videos. she is probably just shaking her head.

Reminds me of when I would tear apart disposable cameras as a kid, touch two terminals on the circuit board and deliberately shock myself just to see how it feels

So good an explanation of what is happening with the ground fault circuits.

I've always wondered how a "controlled" mains shock felt and have never been brave (or silly?) enough to try. Thankyou for your bravery and a nice approach using the brass sheets to spread the current! I've had plenty of other shocks from electric fences to car ignitions but started with a 9V battery across my tongue. An interesting tingle.

"It was the 80's, a lot of things that are dangerous now, weren't dangerous...back then" - Matthias W. 2024 I love this 😂

Very cool practical analysis. Thanks!!

This video is like the best advertisement for GFCIS lol.

I'd be willing to bet every single one of us viewing this has shocked themselves (unintentionally for the most part). Not proud of it, but it is a good lesson I've learned. Thanks Matthias!

Very interesting especially opening the gfci. Thank you

This is an awesome video! Thanks!

Really interesting, Matthias! Excellent testing! Stay safe there with your family! 🖖😊

Well that was a rather shocking video Matthias! Well done! 💥💥

This is a certified Matthias Wendell video

I worked in an industrial manufacturing facility, and brushed up against a terminal that was one leg of 380 three phase. Luckily I wasn't grounded. But I did feel it tingle. Another tech wasn't so fortunate. He was checking the 15kv leg of an industrial laser. He was holding the high voltage probe and I guess that insulation was not enough, because it shocked him and ran through his body. He was leaning up against a metal rail and where he contacted it with his butt, it left a burn mark on his underpants. (not sure if that was the only mark). Policy after that was set the high voltage probe propped up and look from a distance.

good informative video nice to see the internals of the switch.

The RU-vid Algorithm just successfully ran the Timothy Wilson Shock Test on Matthias. We just participated in level 2 of the experiment: do you like to watch someone else inflict pain on themselves instead of being bored... yes.

I had occasion to short a 480-volt circuit...something I wish never happened again. I had removed the cover plate on a switch and my uninsulated screwdriver slipped into the receptacle box and touched the hot lead. My finger was down on the driver's shaft, and I got the worst ZAP in my life. My arm up to my shoulder went numb and hurt for about 6 hours after the incident. Great video Matthias but I was hoping to see an Einstein hair result, thumbs up.

When I took the PE exam 26 years ago, I wrote a design and analysis essay on GCFI. 5 mA leaking to ground from the hot side is suppose to be the limit. You will get a good shock but only for a tiny moment as you have shown here. Since then, I have accidentally tested the GCFI on the outside of my house a couple times. Not something anyone would want to repeat.

I did nearly the exact same thing you were talking about at the 6 minute mark, my dad asked me to remove the receptacle in the bathroom and I touched across both sides and got a buzz I'll never forget. Luckily it was just across a single hand.

This was really interesting, I knew that GFCIs have a 5mA trip, never thought of how one might setup an experiment to test it.

You do have intrinsic muscles in the hand. These muscles produce fine movements as well as initiating certain flexion and extension movements. If these intrinsics are seized or paralyzed/rendered non functional, then your forearm flexors/extensors may not work as well as you'd think. Plus nerves work in an upstream manner as well and could inhibit voluntary control. It's not as clear cut as a wire conductor, so best to be safe .

I have been shocked so many times. As a kid, I used to grab old TV from the garbage and play with them and make them explode. Also built a tesla coil a few times. Been shocked with 120v and 240v. Luckily both times is was very brief and although it knocked me good, I was not stuck to the circuit by muscles like some people have been. But i have learned over the years ways to prevent that so I don't get shocked as often anymore

Insane video!

This is amazing, I literally JUST zapped myself the other day and was wondering why the GFCI didn't trip. Can't wait to watch and find out.

I love the callout to the King at the start.

I learned today that RU-vid has AI and/or human "GFCI's" for Matthias' videos.

Always wanted to try this 😂

Very good video👍

Cool video, thanks.

Good job.

I once spent hours trying to diagnose a wiring fault in my 2nd floor only to finally discover that the GFCI in the washroom had tripped, and that outlet was the main feed into a couple of the bedrooms.

That's really good that both the outlet and the breaker has the same trip current (mentioned in another comment reply). I think when electroboom tested them in europe, the whole house trip protection breaker had a much higher current threshold. 🙏🙏

Lol your testing reminds of that James Bond joystick electric torture device game they play in movie 🤣💕👍

Excellent video! TY Many years ago, I tried to trip a GFCI with fingers, it also became too intolerable... it never tripped!🙂

I'm still surprised that GFCI's are not legally required in North America for all circuits in the house. In the UK and Europe they are mandatory, and have been so for at least 30-40 years as far as I can tell. I've also been shocked by 240v when I was in my early twenties. Multiple times. It was not fun!

I knew the current was pretty low, but it’s nice to know exactly how low and how they work. I’ve triggered many GFCI’s in my line of work. Thank you.

I got a good shock once as an apprentice, I threw the pliers away as the current passed from my hands down through my grounded shoeless feet. It wasn't painful but it sure was an experience to test the GFCI this way.

I came here all excited about you getting zapped and was mildly amused

Something that feels more fun, back in high school vocational electronics (1989), we each built our own heathkit osciliscope. On the bottom the of the frame was the main connector terminals for high voltage, and while working on it, I went to turn the scope around on the table, and my finger hit the lead for the high voltage for the CRT. Luckily trhe rest of my hand was on the frame so it only jumped from finger to palm, but I tell ya, never did that again!

Industrial test equipment there was a 15v glass fuse on the Veroboard PCB circuit, I changed it not realising the low voltage fuse was mains 240v - I should have checked first. One of my other jobs was working on production machinery while it was live at 240v wood ladder and a gas soldering iron and some times rubber gloves, because they did not want to stop the production line. We did have special rubber gloves for working on our factory substations live 440v busbars, I left that work to the other electricians. (see "Presel GP-1" 7500v max)

Legend has it that the button still remains lost to this very day

I think the time it takes for the RCD/GFCI to trip, as well as the specific point on the sine wave where contact is made, also influenced the subjective feeling.

Surprised by the description of the protection circuit being a fail-hot, where it requires an action (solenoid energized) to trip rather than a lack of an action to fail-safe.

Was changing a light switch out and forgot the one next to it was a different circuit. Everything was fine until I pushed the new switch back into the box and the tip of my finger touched the screw of the neighbor switch. That was uncomfortable. What was worse was when my dad hit a deer with the van, and we were fixing it enough to drive home. I was using some safety wire to wrap the radiator to the frame. I didn't notice how close each pass was to the terminals of the battery. When my last wrap touched the neg and positive with my fingers between, the wire "sublimated" between my index finger and thumb. That thin line burn hurt for days.

As a kid in the 80s I'd take things apart so I could see how they worked. I took a fan apart and plugged it in to watch the motor run. Silly me, I didn't connect the wires. SILLIER ME I didn't unplug the cord. I'll never forget that feeling and that my dad was watching James Bond on Channel 2. 😂 I never told anyone but believe me, I learned my lesson and have been extra cautious with electrical work ever since. I don't need anymore of that happening to me. Actually, I just set up an electric fence and got zinged but it was because I grabbed the wrong wire. 😜 It was just a little pop. Nothing like the 120v coming out of the wall. Oof!

Haha, "setting off the GFCI... by _hand"!_ Literally!

In Australia these "RCD's" have their current rating stamped on them. They come in a variety of sensitivities but for general circuits you use a 30mA RCD.

I've taken quite a few 120v or 240v shocks at work through the years. Mostly between fingers. I test and fix mains powered devices, motors, transformers etc. I've learned to be a lot more careful with age ;)

Thank you for clarifying that this video is indeed not by ElectroBoom.

My experience with just getting across a GFCI circuit is that by the time you get to "it" (second half of the word) the GFCI has popped.

In China we were taught that 36V is the safety threshold. surprised that it is different in other countries.

I got my first 220VAC "experience" when I was 3 y/o. Had a toy with some metal bars that fitted perfectly in a Danish power socket. Fortunatley my father was fast and pulled me away before any permanet damage was done. It might have caused my interest in electronics though :-) By the way, this was before CFIs was mandatory in Denmark - the early 1960s. I was 12 y/o when I got my next elecrtical chock. Still have a scar on my hand from it. On a side note. Be carefull with this kind of videos. BC just got a strike on his channel for a short, that according to YT's algorithm, was very dangerous.

In my craft room there is about 90v on the ground wire, been that way for a long time but we only detected it when my daughter bought a 3d printer and we got a tingle off the frame. I have never felt it off any of my computers in there, nor the Cnc router etc. South Africa so mains wiring is all 220v 15 A.

Very cool

In the '70s things were even safer. It was my job from about age 9 to reset the breakers which required climbing on top of the dryer in front of the box. Nowadays, the idea of sitting or leaning across a grounded piece of metal while resetting breakers is considered dangerous. Hey, we didn't have the internet back then so unless one of the old guys told you, you just didn't know

I got a shock on my home 230V and let me tell you, it hurt, thou like you said is nothing like striking your elbow into something that hurts more. But it may change from person to person, it is not the same for all, it also depends on some external factors.

I burned my finger bumping 230v phase with the top while touching ground with thr end, years ago, hurt but also actually burned me a little where it arced. No RCD device in those days. Had a few other good wallops at different times and different ways, some violent, eg 10kv at high school left hand to right hand through the chest, threw me backwards into a bench. Low current and no contact, two arcs.

In the early 1960s I could have used a better GFCI. Feature an aluminium ladder, freezing mist, a corded ( naturally ) drill ungrounded with a metal metal case, storm windows, and a rather dumb/ignorant self. The power went from the drill in the right hand, through me to left hand holding onto the wet and iced ladder about under-eve level of a 2 story house to wet ground. I interrupted the current first by sounding a audible alarm then releasing the ladder. At that point it would have been best if I had swung the drill by the cord and launched it into near earth orbit. But no, I wrapped the rung in a towel and continued to install screws until the towel got damp enough to conduct. When my sister had new windows installed last year, she sent me the old screws. I don't know what happened to the drill.

I was always taught that the safe AC voltage is 24V and the safe current is 10mA... RCDs sold in EU are always set to trip at 30mA.

amazing video! you can give Electroboom run for his money. I rather enjoy these types of experiments without the jump scares.

50 VAC and a few milliamps is the exact shock you get from working on old copper telephone lines when it rings ⚡📞

Sounds like an electroboom collab should be on the horizon haha

GFCIs/RCDs/RCBOs...whatever you call them in whichever country you reside have always fascinated me.

I have always wondered about this, how does it feel to trip a GFCI. Is is the current large enough to feel? How bad does it feel? Is it on long enough to feel? You answered most of my questions. Bravo, Sir. My only other thought, which you did mention, was in your slamming you hand onto the table. My thought is that the forceful contact would create pain that might difficult to distinguish from the pain of the electricity. If you ever have occasion to repeat the experiment, perhaps set the hand down more gently.

😆 thank you

I can't even count the number of times i have got stung by 230v ac ... In the time before GFCI... The worse was while holding trying to light a 10000w light bulb (my father was a light designer at national television and we sometime had some awesome huge lightbulbs) i was holding the two wires to the fitting of the bulb with my hand with sticking the other side of the wires in the outlet. The result; the (old fashioned ceramic fuse) literally launched out of the fusebox and the outlet has a large green burn mark that still there to thsi day, some 50 years later

"It was the 80s. A lot of things that were dangerous now weren't dangerous back then." 😂 Moving outlets while smoking a cigarette and pulling the asbestos out of the new socket hole.

My dog decided to chew on the high voltage cable (230v) of a laptop power supply at the weekend. It chewed right through. The RCD tripped and it carried on chewing without even a whimper.

Everyone working with electricity/electronics should watch this.Emergency personnel, salespeople, homeowners,mechanics.Actually ever human being on this planet. Why? Because you get people like me who love working with bare feet.And "forget " about it.Few months back i went outside while raining.Bare feet and all.Something went wrong with solar system and 220vac/50hz it have at its output.Rushing ,working wet bare feet,wet clothes,wet hands.😲Luckily nothing happened,but this video good educational tool why not to be so stupid.Even if there is so much protective circuitry.👍👍👍👍👍

When I was a teenager I used to do a lot of electrical work, 127v or 220v (Brazil has both), I got shocket dozens of times and I'm still here, back there things were safer :D

That plot is basically showing the resistance stayed steady at 11k ohms until37 volts when it dropped to 7k ohms. Pretty cool plot

as someone who's shocked myself many times in and out of the same hand, from hand to hand legs before. I never suggest it! I have tripped afci and gfci both by hitting wires over the years, it was more or less a tiny pulse almost unnoticeable, especially compared to all the unprotected shocks and having dimly lit incandescent bulbs. I also suggest never wiring live or at least not without proper protection gear!

you could run this test with a freshly butchered pork shoulder and get a very good graph of voltage vs current i think. as far as i know, pork skin, fat and muscle have the same electrical properties as human tissue

Keep one hand behind your back when doing things like this (and stand on an insulated platform). Use the back of your hand. If muscles do contract, they contract away from the live source.

Honey, I shocked myself again

Ah, so that's the secret to how you get your hair to stand straight up in a rainstorm.

I would suggest not using your left hand as the side being shocked, even if the path of least resistance is not directly through your chest. I understand the breaker will protect you, but if you screwed up or it failed, you could quite easily have your heart in the fireing line. With that being said, nice experiment, always hear that 50v is the "safe" threshold, it's nice to see this in practice and also see the relationship between voltage and amperage.

When in school (early 70's), we were taught that 5 mA through the heart would stop it.

Getting zapped with 120 is never fun though not really harmful. I was in highschool and in an HVAC class. We had a group middle schoolers come in just to get them interested in the trades. We had a displace with an outlet, light switch and light receptical. It was powered by a suicide cord. Someone screwed up making it the metal plug end must have a short to it so when i plugged it in holding that end I got zapped.

hahahha Matthias are getting more and more wild hahaha

The fact that its slightly irritating without being dangerous makes it even safer though...

In 2015, I had some damage in my radial nerve - it runs down the arm to the fingers - so I had a nerve-conduction test. In this procedure, they stick a needle into your upper arm, clamp an electrode to your finger, and give you a zap that is strong enough to make your arm jerk. I had been warned that it was extremely painful, and it was unpleasant. But, as I went through the test, I realized that the problem was the sensation of having my arm jerk uncontrollably. The actual level of pain was not high. I hope this explains everything.

Thank you for your sacrifice to teach us all 😉 Safety 7th!! 🤣

Years ago, my old electric razor somehow managed to get live 240v on its metal housing, while I was holding the thing. The muscles in my arm contracted and made me firmly grip the razor. It didn't trip the mains breaker. That was not fun. I just stood there cursing until I could finally throw the razor out of my hand. It must've been a couple of seconds but it felt like ages.

I was a dumb kid who enjoyed touching partially exposed plug prongs - it felt like having a curtain of beads very tightly gripping my arm and rubbing rapidly. Probably fortunate i was never able to actually grab things.

Stick welder bending the electrode back in the 1980s I used to get the odd tingle depending n the rods, I think our welding plant was around 70v AC

Post the uncensored video on your website!

That water was grounded, but if it wasn't it wouldn't trip until the full circuit amperage was exceeded. Touch the black AND the white without being grounded and you get full circuit amps because current going into your body is the same as current leaving. GFCI's can kill.