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I'm an electronics hobbyist who's learning from wiring stuff together and searching the internet if something doesn't work. Hence my electronics knowledge is very patchy.

I recently found out that mains voltage cables (in my case 230 VAC) should not be run parallel to data cables, because that could cause interference and voltage spikes in the data signals caused by induction.

I'm working on a project right now, where I made exactly that mistake - lucky me that I didn't power it on with the data cables connected to the Raspberry Pi yet.

So now to my questions:

  1. How far do I need to place the power cables away from the data cables?
  2. Two power supply PCBs are rather close to the data cables as well (ca. 8 cm & 2 cm).
    Could those become a problem?
  3. Is it possible to damage the Raspberry Pi because of voltage spikes from the data cables caused by mains cables running parallel to them?
  4. The mains cables are very close to the metal chassis (which is grounded). Could voltage spikes be introduced to the chassis and travel to the data lines even though the mains cables have been moved? (Forgive me if that's a dumb question.)
  5. A cable powering two 75 W light bulbs runs over the data lines. Could that be a problem?

Image of project with explanations

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  • \$\begingroup\$ I recently found out that mains voltage cables...spikes in the data signals caused by induction Yes, true. However, I have 240 V cables and Ethernet, audio and video (HDMI) cables all running side-by side in the cable holder under my desk. I have no issues with that. The reality is that what you describe can happen but that does not mean that it is always an issue. It depends on the circumstances if it is an issue. If the conductors in the data cables are shielded (some USB, HDMI cables) that will help a lot to prevent issues. \$\endgroup\$ – Bimpelrekkie Jun 29 at 14:47
  • \$\begingroup\$ In your build, the power and data lines are not running next to each other for many meters so in my view, there should be no issue. If you'd have those cables in parallel for 3 or more meters, then maybe it would be better to separate them. But what you have: no issue, I would not worry about it! Try not to fall into the "seeing problems everywhere" trap, instead, look at how similar projects are build and do the same. \$\endgroup\$ – Bimpelrekkie Jun 29 at 14:50
  • \$\begingroup\$ @Bimpelrekkie ok, good to know. I'll just finish wiring everything up and give it a shot (: thy! \$\endgroup\$ – Lorenz Jun 29 at 14:51
  • \$\begingroup\$ Looking at the photo, what worries me more is having PSUs with 240 V and loose wires "flapping around in the breeze". Do tie those lose wires tightly in place as 240V in a place where it should not be will for sure cause damage and sometimes not only to the electronics. \$\endgroup\$ – Bimpelrekkie Jun 29 at 14:56
  • \$\begingroup\$ these are the data wires which are not connected to the raspberry pi yet. I usually duct-tape them somewhere when I switch everything on. plus they have female pins so I would be very unlucky if they somehow make a connection. when everything is finished they will be cable-tied under the rail \$\endgroup\$ – Lorenz Jun 29 at 15:05

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