I'm not at all an expert in electrical engineering so I'll try to do my best of explaining my issue.
I live in Finland and I own an apartment that was built in the 80's. There has been some renovations done and the kitchen and the bathroom have been updated with grounded plugs as per regulations. Nowadays grounding is done with the 3 wire system where the ground is it's own separate wire, but for old building like this that do not have a separate wire for grounding, it is allowed to do the grounding per plug basis by combining neutral/ground which I think is called TN-C-S network. Until the building management agrees to upgrade the building's grid to 3 wire system, this is my only option.
I would like to update plugs in other rooms to be grounded as well to get rid of any possible noise and give the possibility of using surge protectors as they require grounded plugs or even better, get surge protection on the grid itself if possible.
- Is there any benefit of using a system of combining neutral/ground at the switchboard (behind a residual current circuit breaker there) and bringing the wire from there to the plugs as opposed to combining the neutral/ground behind each individual plug?
- Are there any other ways I could make sure my electrical equipment is protected from noise or power surges other than buying external equipment like UPS?
In my old apartment, that had a very outdated electrical grid with no grounded plugs, I experienced some sort of noise or power surges that caused issues with my PC and router causing them to randomly restart or drop internet connection. One time one of the PC's power supplies died because of a thunderstorm. I would like to get the best protection possible from those kinds of issues and would prefer to do as much upgrade as possible to the apartment's grid itself not having to mostly rely on external devices.
Edit. To add, the current switchboard is old, from the time the building was built so it has no residual current circuit breakers etc.
Edit 2. I had electrician come over and plan the renovation, but the way he dismissed my worries made me want to look for second opinion.
Essentially, as far as I understand or how he made it sound, only way to get grounding is connecting neutral to ground and this can be either done at the switchboard and delivered from there to the outlets or on each individual outlet just connecting those two behind each of them to make them grounded.
I've read about the dangers of this kind of setup and I was under assumption that doing it the switchboard way is safer. Is this true? The electrician said there's no difference and doing it the switchboard way is just extra work for no gain.
I found an image to illustrate the difference in which the setup on the left is what I want and setup on the right is what the electrician recommends to do instead.
Edit by Harper: This drawing neglected something critical. I added it in red: actual system grounding.
Update: I'm not sure what the image I posted was missing, but as I said, I have no knowledge about electrical engineering. To recap: The circuit breaker panel in the apartment does not get a separate grounding wire. Only wires there are neutral and live. If there's any grounding at any point, it would be at the building's power center. I am not allowed to do any modifications to the wires from the power center to my apartment.
Looking at the comments and after talking more with the electrician, it seems that it is indeed best to do the wiring at the panel instead of at each individual outlet. The panel will be replaced with a new one and all the circuits in the panel will be protected with RCD's. Obviously the best option would be to have all three wires completely separated (TN-S), but until the building's grid is upgraded, there's nothing else I can do. At least the apartment will be ready for future (hopefully) upgrade of the building's grid. The electrician clarified that the current grid in the apartment is TN-C and after this renovation it will be TN-C-S. Thank you all for your replies.