0

I have leaking currents issues in my apartment. There are some appliances in the apartment that don't have a problem with a wall socket that doesn't have a ground; like, TV, mobile charger, laptop charger, water heater, clothes washer, electric oven and router.

But there are other appliances that have a problem and need grounding to get rid of these leaking currents in the apartment which are; the PC rig power supply and my dish washer, but what is the reason of getting electric shock in my apartment ! I don't know.

The dish washer most the time shock me when I touch its internal metal surface, and my PC power supply is under the stress of leaking currents all the time ! Every time I touch the edges of the case I get an electric shock.

I thought the power supply is faulty, and I bought a new one and the same problem ! Then I learned that power supply need the ground but why exactly, I don't know.

======================================================================

Now it come to the configuration of electrical installation in my country. We now in modern cities, have 3-ph, star connection to the main panel of each apartment. Between each phase is 391V and any phase with neutral is 220V.

I think the neutral is also connected to the earth because in the main panel there's a big black wire that's going down with the 3-ph cables too. But I'm not sure if it's really going to a REAL ground of the building.

========================================================================

OK guys I have some new stuff I found inside the apartment :)

Today I did a trick that my colleagues told me to do.

Which is to connect the power strip and measure the voltages between L-GND and N-GND, and the results are interesting !

Without a power strip, that if I connect the DMM to the wall outlet directly then I won't find any voltages between L-GND and N-GND. But when I connect the power strip I find that L-GND gives 103V and N-GND 85V !! Why that ??

There are the photos I took this evening.

I did 2 tests with the DMM. 1 is using only one DMM probe and the other is floating 2 using both DMM probes.

  1. First floating test:

This is live because it gives 23V floating1

This is of course is neutral floating2

  1. Voltage from L-GND and N-GND on the power strip:

This should be L-GND because it's higher voltage of 103V

L-GND

This is N-GND

enter image description here

This is the power strip from inside:

enter image description here

migrated from electronics.stackexchange.com Oct 3 at 19:47

This question came from our site for electronics and electrical engineering professionals, students, and enthusiasts.

  • 7
    this DOES NOT solve the issue. This may make symptoms go away but if you're getting electric shocks in your apartment you need to get an electrician because there is a wiring fault that you cannot fix yourself – Hearth Oct 3 at 17:53
  • 3
    Are you in the UK? Is that a UK socket? Are you sure you have 3 phase? And don’t do what you are suggesting - get an electrician because it sounds unsafe at the moment. – Solar Mike Oct 3 at 17:55
  • 5
    This is called "bootlegging ground" and is a Bad Idea™ for reasons such as i) it will stop tripping GFCIs; ii) any external metal will now have a potential and and iii) if there is no proper earth, then if there is a failure in the neutral between this socket and the panel, then the chassis will now be at line voltage. – BB ON Oct 3 at 18:02
  • 1
    But you have not said the country... – Solar Mike Oct 3 at 18:36
  • 1
    Devices with grounded plugs need the ground, this is no surprise, and even manuals may mention this. They need it for various reasons, for example they might just ground the metal case without any other purpose, or in case of computer power supplies, they have filter capacitors from Live and Neutral to Ground, so connecting those to ungrounded outlets will actually make the filter caps to work as capacitive divider and that will make the computer "ground" to actually be a 110V AC voltage. – Justme Oct 3 at 18:41
4

In an improperly wired electrical outlet, yes this might help (depending on the configuration). But you should not connect ground to neutral. Neutral is for carrying return currents and can develop a voltage on it, it should not be shorted to ground. If you do short it to ground, you have a potential for a safety hazard as the chassis of the device your plugging into the wall could have a potential on it. During a fault the device chassis could also gain an unsafe potential on it.

The best thing to do would be to have the wiring fixed to the appropriate IEC standards.

  • Yep .. you're right! I discovered other issues this evening! – R1S8K Oct 7 at 20:46
  • I update the post .. – R1S8K Oct 8 at 9:27
4

UPDATE - OCTOBER 26th 2019.

The OP has now connected the neutral to ground at the power socket.
This is against all advice from all people commenting.
He is completely ignoring the advice supplied by everyone.
He is wasting their time.

People who do what this guy has done this will kill themselves and their friends.

Don't be like this guy.

_____________________________________

Doing what you suggest may be fatal.
Dying will mean you do not have the problem any more but is not the best solution.
Ground and Neutral are NOT identical in functionality and need to be isolated from each other in use (despite being connected at the switchboard).

There are some appliances in the apartment that don't have a problem with a wall socket that doesn't have a ground; ... But there are other appliances that have a problem and need grounding to get rid of these leaking currents

If, as you appear to be saying, the problem occurs with only some appliances only when a power outlet without ground is used then the correct solution is to use outlets which DO have a correct ground connection.

The reason that the problem exists is probably due to noise reduction capacitors in the input circuitry to the appliances concerned. There are two "Y" capacitors connected between ground and Phase & Neutral. When the ground lead is correctly connected the two capacitors 'carry noise currents to ground'. But, when the ground connection is floating the two capacitors form a voltage divider between phase and neutral, with the appliance chassis ground at the midpoint between the two capacitors - forming a high impedance connection at about half supply voltage. This then causes electric shocks between the appliance body at about Vmains/2 and a user connecting between boy and ground (via shoes or hands or ...) will feel a shock. This is usually unpleasant but nowhere near as severe as a full mains to ground shock. If the shock you feel is more a highly unpleasant bite than a muscle spasming grabbing blow then you are probably experiencing a Y capacitor shock.
Use a grounded outlet!

  • Thank you so much I really liked your answer, that's is pretty much the reason for the problems I have. The noise capacitors .. I really liked that part of the your explanation. They should be the reason. The shocks are unpleasant, but also dangerous for my PC parts, I lost a GPU that costed me $400! I got a new one and I don't want to lose it again ! it's also for $470. – R1S8K Oct 4 at 7:58
  • I think the best solution is to ask our electricity company, and they would tell me if the neutral is grounded at the main district power distribution room. – R1S8K Oct 4 at 7:59
  • @R1S8K The best solution is 1. to use an outlet with a grounded earth pin. 2. To understand the probable reason that you get a shock with a completely properly working appliance when there is no ground connection - as I described. || Ground and Neutral are often joined at the switch board. This produces a different result than joining them at the socket. The latter disables modern protection equipment (GFI / ELCB / ...) and adds a hazard – Russell McMahon Oct 4 at 10:54
  • 1
    @R1S8K Death is too good for some people - apparently you wish to share it with others :-(. || You have completely ignored everything that everyone has told you. You have failed to report on the basic tests suggested that would prove the fault is not what you think. You have taken the most lethally dangerous option. Killing yourself or someone else is now more likely. Does that sound lower risk to you? – Russell McMahon Oct 26 at 6:02
  • 1
    @R1S8K To quote "zerowing" / "All your base are belong to us": " You have no chance to survive, make your time. Ha ha ha ha" -> except, here, nobody is laughing. You have been told many many many many times by many many people that what you have now done is lethally dangerous, stupid, non-standard, and may kill you or somebody else (or both). You have ignored this advice consistently and just kept on insisting on doing it your way. The correct way is listed in my and other answers. || If somebody dies you may be legally guilty of manslaughter. I understand that you are in Saudi Arabia :-(. – Russell McMahon Oct 27 at 1:16
2

The problem is your ground terminal in your socket is not connected

You need to do one of these:

  • assure that your local main panel has a grounding electrode actually going to earth, and then, you need to run an electrical wire from the socket in the wall to your main panel.
  • Install an RCD (also called GFCI) device to protect this circuit, however this will be a waste of time since it will simply trip the next time you get shocked.
  • Install an isolation transformer, and ground it.

I get where you don't want to do anything like this, or anything at all. That means you will continue to get shocks, and the shocks will have a chance of killing you, or family, or guests. If you are the responsible householder, this could result in lawsuits or even your imprisonment since you were aware of the problem and did not fix it.


The other problem is, that since you are keen on not fixing this, you are using your brain to create rationalizations as to why you should not need to fix it. These are lies. You need to fix it.


Do not connect neutral to ground at the socket. This is dangerous, and will also defeat the protection of an RCD device. Ground is only connected to neutral in your main panel.

Some believe that if a wire is grounded in one place, then that wire is grounded everywhere. No. That is absolutely not true. If you doubt that, then think about this: why on earth would all the first-world nations spend 50% more copper putting a separate ground wire in every cable? If neutral was as good as ground, why run ground?

Location matters. The neutral being grounded in the service panel (if that's even true) doesn't buy you anything out on the branch circuits.

So yeah, the transformer presumably has an Ufer ground going into the transformer pad, and that ground ties to the supply neutral there. This is an equipotential bond designed to assure the transformer secondary voltages are within 240V of ground.

However, that is of limited help in the residence - it needs its own ground grounding out the panel. That's because neutral service wires do in fact fail. I had one earlier this year, in fact. If you had been relying on the neutral wire to obtain ground from the transformer's equipotential bond, your ground voltages could be floating at anything. That could be cataclysmic, if the transformer's primary is leaking even a little.

Your own house's panel needs its own grounding electrode system (ground rods or Ufer).

So, your main panel in the home also has one neutral-ground equipotential bond, again for a variety of purposes but it also backstops the transformer's ground. This ground bond is only useful inside the panel. If you want ground somewhere else, you need to bring it there.

Now you notice that your panel is not set up as a neutral bar, a ground bar, and an obvous neutral-ground equipotential bond that you can point to. The N-G bond is implemented just by spamming everything onto the same bar. That's perfectly legal, but it's a shame, really; I prefer neutral and ground separate with a distinct equipotential bond that I can clamp an ammeter around to measure leakage.

Out at the outlets we need a way to get ground to them. Neutral is not the right way, because again, the neutral wire could fail (common failure) and then you're electrifying every ground in the circuit.

If your house doesn't has grounds (remember: metal conduit is usually a valid ground path), then you can retrofit the ground wires. You can't normally just add a single wire to a circuit, but ground is special.

  • I update the post .. – R1S8K Oct 8 at 9:28
0

No, you should not connect ground to neutral at the outlet.

Worse yet, your breaker box is lacking a ground so there is no easy way to fix this. There should be a fifth (green) wire coming into your breaker box. Without a ground, you can never fix this in your apartment, it needs to be fixed at the distribution point further back. The ground should be distributed separately to the outlets, it should never carry current.

This is the best diagram that I can find. Unfortunately, it doesn't show the ground. But, it does explain the phases better than your diagram.

enter image description here https://www.practicalmachinist.com/vb/transformers-phase-converters-and-vfd/need-design-information-440v-3ph-220v-1ph-out-319025/a.jpg

Note that I have never seen 3-phase to 1-phase distribution in a residence, but it is used in factories in the US (at roughly half the voltages shown in the diagram, 208V/120V). The neutral is connected to earth ground at one point, normally where the power enters the building, it should never be connected anywhere else.

  • 1
    Information only: US outlets are usually +/180 degrees separated as two 1/2 windings on a transformer. What he describes is true 3 phase with 230 VAC phase to neutral and 400V phase to phase - which is what we have in Newzealand. Most hones only have 1 phase supplied. Mine has two as it long ago had 3 phase supply and this was dropped back to 2 phase when the plastic moulding shop in the backyard was emoved - two owners before I bought the house. – Russell McMahon Oct 4 at 0:39
  • Thank you so much for the explanation. But what if the neutral is grounded at the distribution point? – R1S8K Oct 4 at 8:03
  • The neutral probably is grounded at one point, where the output of the transformer enters the building. – Mattman944 Oct 4 at 9:00
  • You got that from the pictures I added, right ? Because you maybe thought that I'm getting the apartment electricity from some poor distribution system? So you think the neutral is grounded, right? I'm pretty sure that bootlegging the ground would work because one of my friends did it and it's working fine with him in the same city. I posted this thread to learn something of countries and how things are going. But also at the same time I wanted to know that if electricity companies actually ground the neutral at distribution points. – R1S8K Oct 4 at 10:28
  • 3
    @R1S8K "Bootlegging the ground" WORKS in the same way that taking the batteries out of a smoke alarm does - it disable a source of annoyance and substitutes a lethal kluge that can kill you or others. || "Makes me feel good" and "is the correct solution" are quite often not the same. – Russell McMahon Oct 4 at 10:57
-1

enter image description here

It turned out that the neutral is grounded. The electricity company is actually grounding the neutral from the distribution room. That's why they are grounding the main building panel.

I bootlegged the neutral to ground and it works fine now.

I actually not considering that bootlegging is a SOLUTION. But according to the fact that the neutral is grounded, then this is a good solution now to get rid of those floating voltages on the house appliances.

  • That ground connection is legal and technically correct. it is NOT THE SAME as connecting ground to neutral at the socket. || As shown here, with PROPERLY WIRED SOCKETS (1) If an appliance has dangerous leakage currents to ground then ground-fault-interrupters in the switchboard or sometimes in appliances will trip and save your life. (2) In the event of a Phase to ground fault in an appliance there will be a conductor from fault to switchboard ground with no other load current on it to assist with fuse tripping. (3) If you get an appliance fault where phase connects to neutral in the ... – Russell McMahon Oct 29 at 22:22
  • First of all thank you so much for your cooperative discussion and your goal to help me, also that's how I know the person that is writing to me is seriously professional ! At least to my standards. So thank you again I really liked this reply by just reading the first lines. But I hope you are not the one that put the negative vote on my answer :) – R1S8K Oct 30 at 8:00
  • That ground connection is legal and technically correct. it is NOT THE SAME as connecting ground to neutral at the socket why it's not the same ?! It's absolutely the same, because the whole panel ground is connected to the neutral, so they are taking their ground from the neutral. And I'm doing the same, I'm connecting my ground to the neutral. And now when I measure the voltage between the neutral and the case it's very very low voltage, 45mV !! – R1S8K Oct 30 at 8:04
  • OK. Apparently you do want robust mode. FWIW no, I did not downvote anything here - but you deserve MANY downvotes. You will not listen. People are wasting their time trying to help you. You are wasting your time even starting to ask questions as you do not listen and do not believe what people who obviously know what they are talking about tell you. || You say " why it's not the same ?!" -> for the reasons I and others have told you again and again and again. You said " ... It's absolutely the same, ..." -> That's calling me a liar and stupid. Read what I and others have said. Consider: ... – Russell McMahon Oct 30 at 9:18
  • ... all over the world people who wire sockets properly run separate ground wires from power points back to the switch board and do not join them at the socket. According to you the whole world is wasting a whole 33% of their premises wiring needlessly and they are stupid stupid stupid. || Does it seem just likely that they are NOT using all that wire needlessly, that the regulations and standards have a reason for existing and that the whole electrical wiring world , governments, regulatory authorities etc are NOT stupid stupid stupid? || Think about it. Very carefully. || ... – Russell McMahon Oct 30 at 9:22

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.