Retrofitting FI switches, older electronics

Well, I'm afraid there's more wrong there. According to the labeling of the fuses, there is a boiler which is protected by a 20 A fuse. There is also an electric stove with only one fuse, also 20A. You should definitely get a professional.

Well, I’m afraid there’s even more wrong there.
According to the labeling of the fuses, there is a boiler secured with 20 A.
There is also an electric stove with only one fuse, also 20 A.
You should definitely get a professional.

I will do that too, but I don’t want to be completely clueless there ;-)
Yes, in the bathroom there is a 230V hot water tank/boiler and in the kitchen a regular stove.

I do that too, but I don't want to be completely clueless there ;-)
Yes, there is a 230V hot water storage tank/boiler in the bathroom and a normal stove in the kitchen.

If the consumers are connected to two different external conductors, then that causes no problems. Unless they were wired with =<1.5qmm. Then the lines would be oversecured.

What exactly does that mean?

That probably two lines have to run over one fuse.

Please get an electrician. He will probably manage to make it work properly. And please don't think about doing anything yourself.

Please get an electrician. He will probably manage to fix it so that it fits. And please don't think about doing anything yourself.

For God's sake! I am the last person to tinker with any electrical stuff. I'm just interested, that's why I wanted to ask here beforehand. Let's see what the electrician says. I hope it can be done without too much effort.

So, the master electrician was here today. Since I don’t like threads where eventually nothing more is written, here is the answer. Much of it is technically expressed incorrectly, sorry, but it was hard enough for a layperson to follow the conversation for 45 minutes ;-)

An RCD can be retrofitted. For that, some modifications have to be made in the fuse box, because otherwise it doesn’t fit, due to too many fuses. For the small apartment, there are also too many fuses, so he will combine some of them so that it fits. The stove currently runs (I think) on only one conductor. However, it could probably be connected on 4 conductors so that it delivers at least 2/3 of its power. For 100%, new wiring would have to be installed, which is not worth it.

Regarding the RCD, it just has to be checked whether any lines are connected or separated. If they are connected, it is a bit more complicated, but still possible.

He also took a quick look next door in the other 2-room apartment. Although that one is newer/more modern, the “electrical condition” is apparently worrying. There is an RCD there, but it only switches the instantaneous water heater, otherwise nothing. In addition, the box is so old that it’s almost falling apart. The wiring is, let’s just say, unusual. There is apparently a lively cable chaos in a much too small fuse box.

Accordingly:
1.5-room apartment: Install RCD, rearrange/combine fuses, “reinforce” stove

2-room apartment: Retrofit RCD for all lines, completely reconnect cables and create order as well as install a larger fuse box. For that, the wall has to be slightly broken open.

The offer will come in the next few days, but he estimates about 800 euros net. I think that’s well-invested money in safety. Even though I hadn’t budgeted for it and would have liked to avoid the expenses.

I hope I haven’t forgotten anything. As soon as I have the offer, I can also gladly specify the exact work to be done.

and please pictures Before / After :cool: