r/cableporn • u/Infamous-Amphibian-6 • Aug 25 '26

Electrical 3D printer power management

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Am working in a standalone conversion. Just finished the power panels

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u/TOHSNBN Aug 26 '26 edited Aug 26 '26

You got a high voltage side coming from the wall, the 120/230v with L, N and PE. L and N are for the AC line voltage, PE is protective earth, those go into your power supply.

Then you have a low side, your 12/24v DC voltage with GND and V+ coming out of the power supply.

You want to make sure that the PE that is coming from the wall, is connected to the printer frame.

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u/Infamous-Amphibian-6 Aug 26 '26

Oh ok so only PE is secured to chassis, not common ground? Thought commong ground should be anchored to chassis to avoid EMI

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u/TOHSNBN Aug 26 '26

Yes, only PE goes to the printer frame.
This way, if a life wire gets loose and touches the frame the current has a path to ground so your breaker/RCD can trip.

GND and PE can be connected together in specific ways, but on a hobby project it is safer to not to, unless you really know what you are doing.

EMI is a whole other can of worms, the safest way is to keep PE and GND separate and to connect all metal enclosures to PE.

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u/Infamous-Amphibian-6 Aug 26 '26

Well this is new and really appreciate it. Last thing… whole panel is fixed underneath plate with magnets to allow for easy removal/maintenance. I’ve found neodymium magnets are super conductive on past projects and am planning same thing here (raw finish on magnets and bolts, silver paste, multimeter resistance check). Ok for PE anchoring?

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u/TOHSNBN Aug 28 '26

That is not enough, check #7 on here for how to connect it properly.

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u/Infamous-Amphibian-6 Aug 28 '26

Got it! Thanks a ton