How to find a cable break with a multimeter?

We have bought an old villa and are currently renovating. We are now looking for cable breaks and have found multimeters for electronic professions on the internet. But how do you use something like that? Can you please help us? Thank you!!!

Hello Dirkbuerger,

if you have bought an old villa and are now looking for cable breaks, I assume that the electrical installation is outdated.

I would definitely contact two or three electricians who can look at your electrical installation, give you advice, and also explain a multimeter to you.

You will surely find an electrician with whom you can do a large part yourself (e.g., laying and pulling cables) and the electrician then connects the wires.

Best regards

K.Brodbeck

It doesn't work like you just connect the multimeter to a wire somewhere and it shows you where the break is. You need to know the specific resistance of the wire, and based on the measured resistance, you can calculate approximately where the break is. If the installation is outdated and partially defective, I strongly recommend renewing it. First of all, an outdated installation is dangerous because fires can be caused by defective wires. Old installations can also increase power consumption under certain circumstances. And if you hire an electrician who spends hours measuring the wires, you pay a lot of money and in the end still have an old installation. That's why it's better to do a complete renewal right away, and you will have peace of mind for at least the next 30 years.

You will surely find an electrician where you can do a large part yourself (e.g. laying and pulling cables) and the electrician then connects the wires.

It’s certainly nice of you to give tips to save money but how is he supposed to know where to lay what? Do I have to run a 3-core or a 5-core cable to the switch? Does the socket need a cross-section of 1.5mm² or 2.5mm²? And what exactly is the difference between NYM-J and NYY? Simply putting something in the wall that can conduct electricity is unfortunately not enough and therefore I think a professional should be involved. It doesn’t help if the electrician comes to connect and can’t connect half of it because the wrong cables were laid. Then it just gets more expensive than hiring a professional right away.

It's certainly nice of you to give tips on saving money, but how is he supposed to know where to lay what? Do I have to lay a 3-core or a 5-core cable to that switch? Does the socket need a cross-section of 1.5mm² or 2.5mm²? And what's actually the difference between NYM-J and NYY?

Just putting something in the wall that can conduct electricity is unfortunately not enough, and that's why I think a professional should be involved. It's no use if the electrician comes to connect it and can't connect half of it because the wrong cables were laid. Then it just becomes more expensive than letting a professional handle it from the start.

Hello KNX-Partner,

I did not write that! Of course, you discuss it in advance with the electrician. It worked like that with my parents. Personally, I would have it done!

Best regards

K.Brodbeck

Hello KNX partner,

I didn’t write that! Of course, you discuss it with the electrician in advance. That’s how it worked with my parents. Personally, I would have it done!

Best regards

K.Brodbeck

Okay, then I have nothing to say. I just wanted to point out the dangers if you do it yourself. Unfortunately, there are enough people who take such electrical installations lightly just because they have seen how to install a switch before. One should always keep in mind that faulty electrical installations pose a danger to life and limb. However, if a professional is available for tips and advice, then it’s all okay.

Regards, Sven