Inside A Circuit Breaker With MikesElectricStuff

High voltage is  not something we usually tinker with at home. In fact, most of us are more comfortable working with non-lethal, low current, low voltage DC signals. When we do venture into the world of high voltage, we prefer to do it vicariously thru someone with more safety training and/or experience.

[Mike] shows us the inner workings of a 240VAC circuit breaker and explains how the different safety features in the device work. In proper MikesElectricStuff form, [Mike] finds out what it takes to destroy the device. Or in this case multiple devices, [Mike] uses his “Destruct-o-tron” to create catastrophic failure in more than one breaker. You can check out the video embedded after the break to learn a bit about how a circuit breaker works, and of course witness the carnage.

If you haven’t subscribed to MikesElectricStuff YouTube channel you should do, he doesn’t post terribly frequently but when he does it is always worth watching.

We have covered videos from [Mike] previously as well as a post discussing problems related to household electricity which relates to circuit breakers.

25 thoughts on “Inside A Circuit Breaker With MikesElectricStuff

  1. Mike’s videos are great I subscribed to them on youtube for quite a while now and have learnt quite a lot. He does good teardowns of items that you would normally struggle toget your hands on.

  2. 250VAC is low voltage, technically speaking.

    I still remember my surprise upon open an MCB and seeing bimetallic strips and levers and stuff. “We trust our lives to THAT?” 9yr old me thought. As I got older I came to understand that simpler was often better and thus safer.

        1. All house currents 120v or 220v can kill you. And it may not be right away.
          What it can do is basically put your heart out of sink.
          If you ever get a shock you should all ways go to the hospital.
          I have been a electrician for over 25 years. It wasn’t till I worked at a Hospital did I find this out.
          It was a old wise tale that a quick zap woo-dent do anything to you.
          I had a chance to talk to a lot of Doctors and became friends with them.
          They anded up telling me that if something was to happen after a shock it would more then likely happen with in 24 hrs.

          Think of your Loved ones. Go and get checked out. I know it is a pain.
          To play it safe all ways turn off the power.

          Even though I’ve been a electrician for so long Electricity has all ways scard the shit out of me….

          1. If it’s just a “auch that hurt”, “I shouldn’t have touched that” quick jab, then I’d say it is safe to just continue on with life. It’s the longer and more serious shocks that might have the time-delay-kill effect. Part of it is that the electricity may have broken enough tissue that the “cleanup” becomes toxic. Having you already IN the hospital when that becomes apparent is crucial.

            (But I’m not a doctor. Although both my parents are and it rubs off a bit. My dad electrocuted himself and had to stay in the hospital for a day…. (he’s still alive and kicking))

          2. So many eggcorns. Fascinating.

            (To those of you who don’t know what an eggcorn is, some examples include “It’s a doggy dog world”, “For all intensive purposes”, “Font of knowledge”, “Mute point”, “Off-quoted”, “Trying another tact”, “Hack-kneed”, “Social morays”, “Internally grateful”, “Well, all be darned,” and so on.)

            I’m not insulting anybody, it’s just interesting.
            “Eggcorn” is itself an eggcorn based on the word acorn.

  3. That was fantastic! A promising youtube channel to explore.

    I think his experiment at the very end shows why the coil pieces got flattened. It wasn’t from hitting things, it was from compressing itself.

  4. Good video but
    an ELCB and an RCD are not the same thing, that is not made clear
    the correct term for the 10000 amp is the “breaking capacity”
    the arc quencher will not work unless the CB is vertical.

    1. These breakers are often mounted horizontally in larger distribution boards. The movement will happen because of the air pressure increase, pushing towards the only opening the other side of the arc quenching plates.

    1. HVB 800kv Sf6 insulated circuit breakers correct? If I’m not mistaken these only have two sets of arcing contacts. Which is impressive considering the previous standard for this voltage was an air blast style breaker which generally had 8-10 contacts per phase.

  5. mike nice to see the destrucotron is still working…… i did some high speed stuff for raging plantet 2 lightning. there is an exploding wire shot in the credits. think it was 10k per second.

  6. Those circuit breakers are out of date. I’ve seen some of the newer ones from Eaton, and they do a masterful job of combining electrical and mechanical systems together to create the circuit breaker. They use current transformers and other sensors to read what’s happening in real time, and trip the mechanical system within a half-cycle (~8ms) if anything is seriously wrong. And the electrical system is on a PCB (covered with epoxy or other material to prevent moisture damage) with mostly surface mount parts (as opposed to the ones shown in the video). It’s always fascinating seeing the engineering design work that goes into these mass-produced electronics that most people don’t give a second thought to.

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