**The Importance of Earth in Electricity**

This right here is plain old soil I gathered from my garden and the thing that blew my mind about electricity when I first started out, was that you can use such soil as an electrical conductor.

I mean yes; here the light bulb acts a big strange because of the size of the copper wires. But if we use bigger metal plates to penetrate more soil; you can see that the light bulbs works perfectly fine with soil as an electrical conductor.

This conductivity of soil, earth or ground or however you want to call it, is one reason why it is so special and important for electricity and thus electronics. I mean there are dozens of grounds around us.

A normal AC appliance cable has a ground wire, my main distribution board has several big ground bus-bars and is even directly connected through a metal rod to literally earth's ground and let's not forget that pretty much every circuit I ever designed has tons of grounds in it.

But do all of these grounds mean the same thing and what is their purpose? Well, in this video I will tell you just that by doing some experiments you should partly definitely not do at home.

**The Purpose of Earth Wires**

Let's start off with the thing everyone of us uses everyday and that is of course AC appliance cable. A normal AC appliance cable has a ground wire, which is used to protect us from getting shocked.

When we use an AC appliance like a washing machine or a refrigerator, it can create electrical shock if there is no proper grounding. The earth wire in the cable provides a safe path for the electricity to flow back into the ground, thus protecting us from getting shocked.

In my case though, I have several grounds connected to my main distribution board, which is also directly connected through a metal rod to literally earth's ground. This provides an additional layer of protection against electrical shock.

But why do we need so many grounds? Well, as we will see later in this video, it's not just about protecting us from getting shocked. The concept of grounding has much deeper meaning and significance in the world of electricity.

**Static Electricity**

Now let's talk about static electricity. You know, when you rub your feet on a carpet or rub your body on your couch and then touch something big and metallic, you should have felt a sudden pain in your finger which was actually a big discharge current.

This is because through the rubbing, we built up an excess amount of electrons on our body which through the touching of the metal object quickly flowed to it, to create an equilibrium of electrons.

But measuring this electrostatic voltage difference is not really easy to do. But with this charge generator here you can easily see and hear that high electrostatic voltages can be a bit dangerous; not only for your sensitive electronics but also for someone working on your solar panels that gets shocked and then falls off your roof.

**The Importance of Grounding in Electrical Grid**

Now let's talk about the importance of grounding in our electrical grid. As I mentioned earlier, the earth mass does not only come with interesting electrical properties; but it is also truly humongous.

That is why when some excess electrons flow into it; its potential that we define as 0V does not really change. And since some electrons get sucked out at one point and some inserted at another point; we truly get a common ground reference potential here.

And that is basically why we earth all metal parts everywhere around us. Now of course the topic of earth goes even deeper than that for our electrical grid and power distribution.

But for now you should not only understand that in our everyday life it basically protects us from getting shocked; but you should also understand why this electrician joke here is funny and not really funny at the same time.

**Grounds in Circuit Schematics**

And that brings me to the last big question; why do my circuit schematics come with lots of grounds? I mean in very rare occasions they do actually mean to connect to earth; but most of the time they simply mean that all those points connect to one common potential which is mostly the reference potential aka 0V of our DC voltage.

So yeah this is not really Earth but since our Earth is a big reference potential at 0V as well; this analogy probably spilled over to schematic designs. And to solidify this analogy I would like to add that when doing 2 Layer PCB designs; you usually use the bottom layer as a big continuous ground layer to which many components on the top connect to which once again is super similar to the Earthing concept we talked about before.

Ok and with that being said you should now understand that Earth or Ground is awesome and why you hear it very often when it comes to electronics.

WEBVTTKind: captionsLanguage: enThis right here is plain old soil I gatheredfrom my garden and the thing that blew mymind about electricity when I first startedout, was that you can use such soil as anelectrical conductor.I mean yes; here the light bulb acts a bigstrange because of the size of the copperwires.But if we use bigger metal plates to penetratemore soil; you can see that the light bulbsworks perfectly fine with soil as an electricalconductor.This conductivity of soil, earth or groundor however you want to call it ,is one reasonwhy it is so special and important for electricityand thus electronics.I mean there are dozens of grounds aroundus.A normal AC appliance cable has a ground wire,my main distribution board has several bigground bus-bars and is even directly connectedthrough a metal rod to literally earths groundand let's not forget that pretty much everycircuit I ever designed has tons of groundsin it.But do all of these grounds mean the samething and what is their purpose?Well, in this video I will tell you just thatby doing some experiments you should partlydefinitely not do at home.Let's get started!This video is sponsored by JLCPCB, who combinethe strength of large-scale flexible manufacturingwith intelligent digital transformation, providingthe most cost-effective one stop electronicand mechanical manufacturing service platform.So click the link below and get their BlackFriday coupons to save money on PCBs, PCBassembly, 3D printing and CNC machining.And now 3D printing prices even start as lowas $0.30, crazy!Now let's start off with the thing everyoneof us uses everyday and that is of coursean AC power cable, that like I already saidcomes with a ground wire, in our case herein Germany it is the green-yellow PE aka ProtectiveEarth wire.And the keyword protective already gives usa clue about its function; but before gettingto that, let's imagine we got a normal householdappliance like my dirty old toaster here.If we hook it up to mains power and turn iton, then we got our brown L1 aka live wireand our blue N aka neutral wire between whichwe have a voltage of 230V that powers ourtoaster.Now as you would expect the toaster is gettinghot inside because its resistive wire thatcomes with a resistance of around 53Ω , nowgets penetrated by around 4.34A accordingto ohms law or 4.4A when measured in reallife.The point why I am showcasing this here, isto demonstrate that with just a live and neutralwire you can power your appliances perfectlyfine.So why do we need an Earth wire here?Which connects to these metal parts of theplug and these springs on our outlet.Well, by using my multimeter, we can prettyeasily find out that ground is directly connectedto the metal chassis of my toaster and itis there, like teased before, for safety reasons.For example, let's imagine the live wire insideour appliance either came loose or the wireexperienced some mechanical stress and thuslost part of its insulation.Now the live wire touches our metal enclosureand I think everyone know that metal usuallyconducts electricity pretty well.So if you touch the metal chassis now thenyou directly touch 230V AC.And because you are more often then you thinksomehow connected to the Earth which is alsoa reference point for our house wiring, wegot a closed circuit and thus current canflow and things can get dangerous for you.To prevent this the earth wire is not onlydirectly connected to the metal housing butalso to our neutral wire.This connection is done inside or near themain distribution panel which I can sadlynot show you because mine is locked there.So as soon as live and earth touch each otherwe got a big short circuit current flowingwhich is a good thing though and to provethat let's simply try it out with the toasterand yes; we got big sparks and all my lightsturned off.This cutout happened because the protectivedevices inside my distribution panel trippedwhich are for one a normal circuit breakerand also an RCB.Now the circuit breaker tripped because ofthe big current flow and the RCB tripped becausethe current flowing through live and neutralwere no longer the same value since this timecurrent flowed through the GND wire.And before doing this test I expected onlythe RCB to trip because it requires way lesscurrent to activate.But hey; both protection would have savedmy life in combination with the earth wiremeaning summarized, its purpose in AC cablesis that we do not get electrified, nice.But did you notice that while explaining thecircuit tripping part; the actual earth, groundor soil never got mentioned; so why is itan earth wire?Well, the reason can be found when followingthe earth wiring inside my panel which leadsto a bus bar that connects to a thick metalrod that is pushed into the earth for sometimesup to 9m.Now as we discovered earlier the earth canbe used to conduct electricity.In my case though the resistance is stillquite high with a voltage drop of around 55Vand of course changes when more or less moisturegets introduced or when sand layers appear.But with such a long rod you usually get apretty low resistance meaning yes; there doexist electrical systems that use the earthitself as a conductor.For us though that is not primarily the usecase; for us it is more about the problemwith static electricity.In case you do not know what that is, thensimply rub your feet on a carpet or rub yourbody on your couch and then touch somethingbig and metallic.You should have felt a sudden pain in yourfinger which was actually a big dischargecurrent.You see, through the rubbing you built upan excess amount of electrons on your bodywhich through the touching of the metal objectquickly flowed to it, to create an equilibriumof electrons.Now measuring this electrostatic voltage differenceis not really easy to do.But with this charge generator here you caneasily see and hear that high electrostaticvoltages can be a bit dangerous; not onlyfor your sensitive electronics but also ,forexample ,for someone working on your solarpanels that gets shocked and then falls offyour roof.My favorite example here is from Marco Repswho actually measured and felt high voltagesat his solar panels.Such voltage gets created in the extreme caseby lighting, but also way more often simplythrough the atmosphere.And that is why we Earth such metal parts,aka connect them to Earth, to get rid of thestatic electricity which I also did in myprevious video about my own mini photovoltaicsystem.The reasons is that earth mass does not onlycome with interesting electrical properties;but it is also truly humongous.That is why that when some excess electronsflow into it; its potential that we defineas 0V does not really change.And since some electrons get sucked out atone point and some inserted at another point;we truly get a common ground reference potentialhere.And that is basically why we earth all metalparts everywhere around us.Now of course the topic of earth goes evendeeper than that for our electrical grid andpower distribution.But for now you should not only understandthat in our everyday life it basically protectsus from getting shocked; but you should alsounderstand why this electrician joke hereis funny and not really funny at the sametime.And that brings me to the last big question;why do my circuit schematics come with lotsof grounds.I mean in very rare occasions they do actuallymean to connect to earth; but most of thetime they simply mean that all those pointsconnect to one common potential which is mostlythe reference potential aka 0V of our DC voltage.So yeah this is not really Earth but sinceour Earth is a big reference potential at0V as well; this analogy probably spilledover to schematic designs.And to solidify this analogy I would liketo add that when doing 2 Layer PCB designs;you usually use the bottom layer as a bigcontinuous ground layer to which many componentson the top connect to which once again issuper similar to the Earthing concept we talkedabout before.Ok and with that being said you should nowunderstand that Earth or Ground is awesomeand why you hear it very often when it comesto electronics.If you enjoyed the show then consider supportingit on Patreon.As always don't forget to like, share, subscribeand hit the notification bell.Stay creative and I will see you next time.