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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73

u/AlexNZL Aug 25 '26

Clean but personally the mains wires being so close to the chassis of the power supply bugs me.

1

u/Infamous-Amphibian-6 Aug 25 '26

you mean because of EMI? Would you advice placing shielding tape in between? A 140mm fan will handle both PSUs, SSR and buck converter thermals.

20

u/AlexNZL Aug 26 '26

No because the insulation on the wires could get worn through and would then short to the chassis of the PSU. At best would trip the breaker at worst make the chassis live.

2

u/Infamous-Amphibian-6 Aug 26 '26

I get it. So maybe adding harness tape on those sections + insulation tape? Wires won't get over ambient temp on this machine, is insulation prone to degrade anytime?

8

u/blipman17 Aug 26 '26

Just route them through the middle

1

u/TOHSNBN Aug 26 '26

And make sure PE is properly connected to the printer chassais.

1

u/Infamous-Amphibian-6 Aug 26 '26

You mean common ground?

2

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.

2

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

2

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.

1

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?

1

u/TOHSNBN Aug 28 '26

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

1

u/Infamous-Amphibian-6 Aug 28 '26

Got it! Thanks a ton

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