A question about grounding. - Page 1
Forum section: electronics / beginners

author: Manafont
author_rank: Newbie
timestamp: July 05, 2022, 02:46:55 pm
content: First and foremost : Sorry if I post this in the wrong subforum. And sorry if this is not the forum that I should ask these thing from, I don't know any other trustable forum.So, my friend has an old house he inherited from his parents.All the wires in his house is a twin, without grounding cable. And these cables are in the brick & cement wall.He wants to use a surge protector for his PC & Audio but heard that he will need grounding (and possibly to try get a cleaner audio sound i think),so he's thinking to bury a grounding rod somewhere in his lawn, then run a (atleast) #10awg(around 6mm²) copper wire directly from the rod to the one wall outlet in his room that he use for PC & Audio.I read the govt guidebook for grounding wire, it says at least #10awg, around 6mm².So in his mind, he plans to make a grounding just for that one single outlet in his room, that he only use for PC & Audio.Changing the whole house's cables is not an option he can afford.A single wire is cheaper than triplets, and running triplets for atleast 200ft (just for that one outlet) is going to burn his wallet.Call an electrician :Most if not all electrician here doesn't give advice for free, more like charge a lot.They also doesn't mind using a 2x0,75mm² wire for a 2400watt appliance. 🙄I'd report them, but not like they'll get jailed. The state, govt, police, whatever won't even bother warning them.Here it doesn't need a license to advertise oneself as "electrician". The govt never checks it, and pretty much doesn't care about it.There's a guidebook from the govt, but hardly ever followed by these "electrician" (if they even know about it at all).additional details : Even the guy sent by the Govt backed power company sometimes skips/ignore some important stuffs in the guidebook, if not outright doesn't know at all.There is an option of calling a big company that usually deals with factory's electricity, but yep...... they cost, a LOT.So, my questions to you guys are :- Is this achievable ?- Is it okay to do it the way my friend wants to do it ? Like, will it cause problem?- Is there another option ?Thank you for your time reading and possibly replying too.

author: golden_labels
author_rank: Super Contributor
timestamp: July 05, 2022, 03:23:38 pm
content: Not an electrician here,but driving a metal rod into ground and connecting it directly to the outlet strikes me as a very bad idea for a general earthing in home.(1)If a lightning strikes nearby, there will be 50–100kV between that rod and power line. Quite opposite of what your friend wants to achieve. In allTN networksthe earth connection is attached to the neutral wire outside the installation itself.But I am not sure if earth connection is actually needed for a surge protector either. Power strips just put them between live and neutral.(1)Some installations useTT earthing, but those are special cases.

author: pcprogrammer
author_rank: Super Contributor
timestamp: July 05, 2022, 04:18:13 pm
content: For the third prong it is normal to use a ground rod near the house. In the Netherlands and France it usually is 25mm2 twisted copper (strands of 2.5mm2) from the main breaker panel to the copper rod. Measurements are normally done to assure a low resistance to ground. Then from the main breaker panel one runs 3x2.5mm2 for outlets. The main breaker panel has a differential circuit breaker (don't know if this is the correct English term for it) before the other circuit breakers.It is this protection device that is important in making things safe.As the previous poster wrote, a simple surge protection won't need it, and just short the pulse between live and neutral, but a better protection might trip the differential circuit breaker and protect against more damage.Be aware that nothing protects against a full blown strike on the power cables. If this happens all the circuit breakers will jump off the walls

author: golden_labels
author_rank: Super Contributor
timestamp: July 05, 2022, 04:36:14 pm
content: pcprogrammer: note that I commented on the rod going directly to the earth pin of a socket. That’s a situation very different from the earth being connected in a manner you described, which is indeed a typical TN installation.As for direct hits, a friend recently had his summer house hit by a lightning. The house is, fortunately, fine. The electric box was blown open. The electric meter inside: if not the debris, you would not know it was there.

author: Manafont
author_rank: Newbie
timestamp: July 05, 2022, 04:37:52 pm
content: Quote from: golden_labels on July 05, 2022, 03:23:38 pmYeah.No ground can be dangerous, jank/bootleg ground can be dangerous tooI think in my friend's case it's more to which option is less dangerous, and what's more likely to happen.Haven't seen or heard about lightning strikes here in my entire 30ish years life, lots of tall buildings with lightning rod as well. And hopefully I never.The grid voltage though.... is not what I'd call stable/consistent.5 years ago I had to use a voltage stabilizer for my PC and high power electronics or it will just either have power related error, or straight up busting my PSU (was using rather cheap PSU in retrospect).Quote from: pcprogrammer on July 05, 2022, 04:18:13 pmMy friend intends to skip the main breaker and go straight to the outlet, mainly because the main breaker is far from the outlet he want to ground (like at the very least 200ft, can go up to 500ft if he wants to be tidy/aesthetically pleased with the cable management) also placed in a seriously complicated place to reach. (Yay crappy first electrician)His PC is like 800-900 watts, so yeah if it ever have a power related cable inside it touching the metal case, as of now (without grounding), he'll be dead. 220 volt.

author: pcprogrammer
author_rank: Super Contributor
timestamp: July 05, 2022, 04:48:48 pm
content: Quote from: golden_labels on July 05, 2022, 04:36:14 pmBasically there is not much of a difference if the third prong of a single outlet is directly connected to a grounding rod, as long as the resistance is low it will work just the same as a central grounding. The central grounding is nothing else then a bar in the breaker box where all the earth cables of the outlets are connected together.Back in the day it was normal in the Netherlands to only have grounded outlets in wet rooms. The living room and bed rooms would just have two prong outlets. But that is history.Quote from: golden_labels on July 05, 2022, 04:36:14 pmHave not had such a big experience myself, but did have an ISDN box, voip gateway and network switch blasted at some point. A lot of the chips where cracked open. Big boom

author: pcprogrammer
author_rank: Super Contributor
timestamp: July 05, 2022, 04:53:39 pm
content: Quote from: Manafont on July 05, 2022, 04:37:52 pmIf the grid voltage is unstable, I'm not sure a surge protector will do much good. An UPS (uninterruptible power supply) would be better. These are better in controlling the output voltage, and also help in saving your work when there is an outage of several seconds to minutes.

author: golden_labels
author_rank: Super Contributor
timestamp: July 05, 2022, 06:05:11 pm
content: Quote from: pcprogrammer on July 05, 2022, 04:48:48 pmThere is one significant difference. In that box the rod is also connected to neutral.And, at this point, I have realized that something is missing.Manafont: isn’t neutral already connected to earth in your friend’s installation?

author: pcprogrammer
author_rank: Super Contributor
timestamp: July 05, 2022, 07:34:19 pm
content: Quote from: golden_labels on July 05, 2022, 06:05:11 pmNope, not in the Netherlands nor in France. The neutral wire is connected to ground in the transformer station.If it was connected to the ground wire in the breaker box, it would have to be before the differential circuit breaker, otherwise that would not function.

author: Kjelt
author_rank: Super Contributor
timestamp: July 05, 2022, 08:54:59 pm
content: There are some requirements for the earthing rod however.Not only should it be copper but also deep enough that even in the driest summer it still has low enough resistance, preferably contact the always wet ground water level.

author: golden_labels
author_rank: Super Contributor
timestamp: July 06, 2022, 04:11:32 am
content: Quote from: pcprogrammer on July 05, 2022, 07:34:19 pmRight, even before “the box”. Doesn’t matter at all. The point is: it’s connected to neutral and the connection is made before the actual “in-home” part of the installation.

author: Monkeh
author_rank: Super Contributor
timestamp: July 06, 2022, 04:18:13 am
content: Quote from: golden_labels on July 06, 2022, 04:11:32 amBut the rod is not. This is the difference between a TN and a TT installation.

author: Manafont
author_rank: Newbie
timestamp: July 06, 2022, 10:07:12 am
content: Hi guys, sorry for late reply.I had to go to my friend's house to test some stuffs first.I'd tell him to answer these himself, but I and He know telling him to explain technical stuffs in english is pretty much telling Shrek to explain dark matter & gargantua.Quote from: golden_labels on July 05, 2022, 06:05:11 pmI think so, at the very first breaker from the utility pole(the meter we call it). I did see a bit of wire coming with insulation color that are stated to be used only for ground wire in the govt issued guidebook.Wether or not it is connected to an actual rod, or just copper wire with it's insulation stripped then plugged the ground, I don't know, the rest of the cable is buried inside cement wall that was made with hardener. (a.k.a took me a good 5 minutes to drill a 4mm, 4cm deep hole with a dewalt corded impact drill, to the point that the drill bit starting to become red and hot)It is also located right under the meter, and it's a very dry ground, that spot never even get hit with water when watering the lawn according to my friend.I'd ask his parents, but his parents also don't know, since they left the process of installing electricity to the "electrician" they called back then.- I tested with a multimeter on outlets inside the house, Neutral + Live = 218-230v, Ground + Live = varies, but most i get is 70v.- Outlet tester says open ground.- All outlets are schuko type, but all the wires inside the wall are twin wires. (Why? I don't know. Lack of respect of one's own profession maybe)- GFCI, ELCB, RCBO is not a thing here. We only ever knew about it this year.Quote from: pcprogrammer on July 05, 2022, 04:53:39 pmI was saying how bad the power quality was just to show that in my honest opinion, it is more likely that we or our electronics get killed by the power that comes from the grid than from natural causes.It is kinda much better now (I don't really have to use a voltage stabilizer for my sensitive equipment to work), but looking at our electricity pole in front of my house alone pretty much leads me to thinking : "I won't count on it"I can give you a pic of it if you want, but i'll try to explain in wording first.You will see multiple wires from pole to pole, some wires are going through thick foliage, some wires are more loose than others, placed lower than my 2nd floor balcony.All over the country. The best part is, it's not even the 3rd worst I've seen in my state alone.He use a Line-Interactive UPS for his PC, although that UPS often having problem that the manufacturer can't figure out why.Since when he brings it to claim warranty, they tested it, and they found no problem. He brings it home, it start having problem again.So the manufacturer basically said "Oh well, maybe the battery's voltage turning bad, we'll change it for you"Repeat this for 4 times.His 1 year old UPS has changed battery for a total of 4 times, while barely used.One time (2 months after his battery changed) his electricity is down, his UPS keeps tripping on and off repeatedly until he turn it off completely.He brought it to the service center, they tested it for 3 days and found no such problem.He said he often hear a buzzing sound in his room, when he is near his PC & Audio that doesn't come from his PC & Audio.Quote from: Kjelt on July 05, 2022, 08:54:59 pmMy friend read the govt issued guidebook, the rod needs to be atleast 5/8inch, atleast 1 meter long, the wire needs to be atleast #10awg, or 6mm².There's a spot in his lawn where if he dig more than 70cm, the hole will be filled with water. So yes, that soil gonna be wet all the time.======================So basically, after asking for more info from my friend.- He wants to protect his expensive equipments (PC & Audio), so he thought about buying a surge protector, atleast for Audio.Then after buying it he reads that surge protector works by sending that excess current to the ground.- Also that he's kinda worried/afraid, since his PC & Audio is near him all the time, and he often either accidentally touch it, or have to touch it to work something on it.The trigger for this is that when he touched his PC case and move his hand without shoes, he feels like it's vibrating softly. But it disappeared when he's doing it while wearing shoes.The same thing happens when he's rubbing the cement wall near his work desk.- He wants to do it right (changing the whole wiring & breaker system), but it's not an option he can afford.He calculated that he needs atleast $5000 to do it, if it's done by just putting the cables on the wall. More money if he wants the cable inside the wall.Not to mention that trying to find an electrician that has some modicum of standard is hard.

author: wizard69
author_rank: Super Contributor
timestamp: July 06, 2022, 03:23:49 pm
content: After reading this post I have to say your friend needs professional help!!!!!!! Either that or find a tech school that teaches home owners proper wiring. If you friend is getting an electrical shock, no matter how mild, from his audio equipment he is not far from being killed by that electrical fault.Now I have no idea what the electrical standard is for home installations in your country, so I can only suggest things from a general standpoint.First; determine if your main electrical panel is modern and properly installed.Second; determine if the panel supports proper grounding and that the grounding is properly connected. In the USA you would have a single ground connection at the panel to earth (the ground rod) in most cases. Areas with poor electrical conduction, with respect to earth, may need more advance ground references.Third; buy 2 conductor cable, with ground (commonly called Romex in the USA), properly sized and run it to the sockets/outlets.Now I hate to say this but your friends attitude about the cost of doing it right is pretty common in the USA too. That is they don't want to come up with the money to do mitigation work correctly. This is one reason why I don't do contracting work for homeowners. This is often the cause of tragedy so talk to your friend about his life and doing the work correctly.Frankly from the description of the state of electrical contracting in your area I'd almost certainly look into getting the training to do the job yourself or your friend can do the work. Assuming the proper training is available it will leave you with peace of mind to have the job done to better than local code.Yeah I know that a roll of Romex costs a bit and the possibility that the electrical panel may need replacement, inflates cost a bit but it is best to find a way to do the job correctly. Sometimes DIY is the only economical answer for a home owner.Quote from: Manafont on July 06, 2022, 10:07:12 am

author: Kjelt
author_rank: Super Contributor
timestamp: July 06, 2022, 05:22:42 pm
content: Quote from: wizard69 on July 06, 2022, 03:23:49 pmWhere do you read that?He saysQuoteWhich is quite normal if you do not ground any metal device with a C14 connector, because those need to be grounded.Even ungrounded devices that are connected to a double isolated powersupply can give you this soft vibration/electricity sensing feeling.I have it all the time when i hover my hand over the back of any ipad when it is connected to a charger, and yes official Apple charger and cables.

author: Manafont
author_rank: Newbie
timestamp: July 07, 2022, 11:42:56 am
content: Quote from: wizard69 on July 06, 2022, 03:23:49 pmIt's an old house, it's not a modern one for sure, at the very least not entirely modern.My friend would spend the money if he has some. I realize the sentence "PC & Audio" might insinuate that he's actually wealthy, but no.His PC is a frankenstein made from parts I no longer use, so that maybe he can do some designing side-jobs.His audio was something he won then upgraded by DIY using parts taken out from broken stuffs. (Capacitors, etc)Here an "electrician" gonna ask for atleast $15 per 1 Plug / 1 Bulb fixture / 1 single breaker, basically per 1 load. Just for the service.Mostly will only splice cable by twisting them then use an electrical tape. If you want wire nuts, they'll charge more for their service, and you have to buy the nut yourself.And most of them don't even have a proper crimping tool. They'd use pliers and hammer. Let alone that expensive tool to measure ground resistance.For comparison, this is a country that has govt regulated minimum monthly payment of $150, and there's a LOT of such workers.There's a lot of DIYing about electricity in the country, not because people here are stingy, most can't afford it.let's say they need to install 3 breakers, 3 single plugs, 1 double plugs, and 4 bulb fixtures. That'll be :3 + 3 + 2 + 4 = 12 loads total x $15 = $180 for the service alone. Even if those things is only like 15inch away from the breaker.Below is a photo of a breaker hole (yes, hole, not box), that a licensed electrician worked on. (My friend's house)

author: El Rubio
author_rank: Regular Contributor
timestamp: July 07, 2022, 12:50:56 pm
content: One thing you can do is install a 1:1 isolation transformer. All of the audio & pc equipment would be powered by it, so it has to be of sufficient current. You can then drive a ground rod and connect it only to the secondary side of the transformer. This would isolate the ground rod and keep it from becoming the main ground during voltage surges. You want everything connected to the PC or Audio powered on the secondary side of the transformer. If you were to power a cd player on the regular electric ckt, the interconnects become a path to ground for any surges.