ZINZIRIO wrote: ↑20 Apr 2025, 10:12
How can I know from my side if I have to connect with TN-S, meaning a different ground for the neutral than for the safety ground, or a TN-CS that shares the same, neutral and safety ground on the same rod?
You might be able to guess from looking at the breaker panel: Think about your panel for a second and go back in time to before you made
any changes or modifications. You said you get 2 wires delivered to your main electrical panel from the utility. First question to ask would be if you live in a house or if it's an apartment building. If it's a house, make sure the panel you're looking at is actually the main panel for the whole house. If it is, you should look at the color of the wires coming in. One of them is either black, grey or brown. That would be the live wire. The other one is colored either blue or yellow-green striped with blue mixed in. If the second wire is blue, it's a TT system, and if it's yellow-green striped with blue mixed in it's a TN-C-S system. However, color coding isn't always done right and can be wrong. So, for you to confirm it, think about the connection between the second wire and the grounding wire. Was there a connection there in the first place, did you take it out or was it not there at all before? If it wasn't there, it's likely TT, if it was it's likely TN-C-S.
More hurdles for you: Is your main panel actually the first thing the wire from the utility encounters inside your house? There might be a box we call "Hausanschlusskasten" (=house connection box). It contains the main fuses for the whole house. It looks something like this:
https://upload.wikimedia.org/wikipedia/ ... A_500V.jpg This contains the 3 main 63A fuses (I have a 3-phase installation). If the electrical installation was done right and you're on TN-C-S, the PEN wire should be split up into PE and N inside this box. However, after this box, there should then be 3 wires going to your main breaker panel, 1 phase, 1 neutral and 1 PE/ground. Is your incoming wire a PEN and was it split up inside this fuse box? I for example can't tell, because it's sealed and only licensed electricians are allowed to open it up (it's before the electricity meter). Maybe your installation is supposed to be TN-C-S and somebody forgot to run the PE wire from the main fuse box to the breaker panel. Maybe you're getting a blue neutral wire, which would be a regular TT, but you're actually supposed to get a PEN. Or maybe it's just a regular TT and it's supposed to be like that.´If you're in an apartment building, it's even more convoluted as your breaker box definitely isn't the first thing the wires encounter within the building...
In short, the safest and most reliable way of figuring out what your grounding system is supposed to be is to call the system operator and ask. If they can't answer, call a licensed electrician. If he won't tell you, either call another one or have one come to your home and check the installation.
ZINZIRIO wrote: ↑20 Apr 2025, 10:12
But my question is which system to use, assuming that with either of the two the problem never returns.
That's a question only the utility will be able to answer. You can make a good educated guess, but you can never be certain. The grounding system is governed by the utility, more specifically by something we refer to as the "Netzbetreiber" (=electrical system operator), the company that ownes the physical infrastructure. This doesn't necessarily have to be the company you pay, as companies can resell foreign infrastructure, similar to internet providers. Try calling your power company first. They might or might not give you the information. If they don't or can't, call the system operator. Your electricity meter might have a sticker on it with a phone number to call in case of a fault, and that number usually belongs to the system operator. They will definitely have the information on your grounding system, however they might not give it to you. In that case, call a licensed electrician. Any electrician worth their pay should have access to the database of the grounding system used at your address, and they should also be able to tell immediately from looking at the panel if everything was done right.
ZINZIRIO wrote: ↑20 Apr 2025, 10:12
Today I made the connection from TT to TN-S and the mouse becomes very fluid and all the desynchronization problems disappear...
Could indicate that your grounding is really bad or non-existent. You mentioned in a previous post that you found a connection from your earthing system to the water pipes. If your water company ever changed out a bit of pipe, they very likely inserted a plastic piece. This nullifies the grounding in your house. If this is what was relied on to create the safety ground for the RCD to trip, I would
highly suggest getting an electrician anyways, because your installation might very well not be safe anymore.
Here's my honest advice: Call your utility, system operator or an electrician and get info on which grounding system is used at your address right now. After making that call and having it confirmed, post the result here. If it's confirmed that you should be on TT, get an electrician to check out your installation and have him take a measurement of ground resistance and RCD trigger times.
Weird mouse input and computer problems aside, a TT system without a proper ground rod and therefore too high of ground resistance is a huge safety hazard and you should get it fixed ASAP.
EDIT: Apart from the safety concerns, I still stand by the opinion that the safety grounding doesn't influence the computer when under normal conditions. There are countries whose national electric code doesn't even require a 3-prong outlet and devices are never grounded. One such example is Egypt. Nevertheless, people from Egypt can play video games just fine and not every Egyptian ever in the existance of the country suffered from weird mouse problems or desync. Safety ground, apart from the obvious function as a safety feature, doesn't have any function inside the computer. It's there for one thing only, to protect the user in case of a ground fault.
The fact that the safety ground is bonded to the DC ground inside the PSU however might lead to weirdness, but why that would happen and under which circumstances I'm nowhere near qualified enough to make sense of. What I've seen so far, noise, interference or whatever else might be on the safety ground which isn't supposed to be there, can influence the way a computer functions, possibly by changing the path the DC return current takes back to the PSU. It's the best guess I have so far.
