I am working on a project to design an enclosure for my 3D printer. The enclosure is designed, but I am looking for some guidance/suggestions on the electrical side. I plan to add a few strips of 24V LEDs above the printer for lighting, and an external 12V centrifugal fan that will be used to filter air. My goal is to remove the PSU from the printer and mount it outside the enclosure to improve cooling (currently it faces the table top in an unenclosed environment. Second I want to add three DC switches that allow me to toggle power to the printer, the LED lights, and the fan. I have attached a diagram showing how I plan to wire everything. I want to use the current main switch from the printer to control power from the wall (AC) to the PSU. From there I would like to be able to route the 24V outputs (of which there are three) from the PSU through each of the switches so I can turn on the printer, the LEDs, and the 12V fan independently of each other if needed. For the fan I have a buck converter to step down the voltage to 12V.

My questions are as follows:

  1. Is this as simple as just finding three switches that can handle 24V and a high enough amperage (20A to be safe) and wiring them up as described/shown?

  2. Are there any obvious (not to me) issues that I am not seeing?

  3. Are there any suggestions for an appropriate switch to use, I am having trouble finding a suitable 24V switch (probably because I am unfamiliar with where to look).

Any and all advice/feedback is appreciated. Thank you!

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Update 2023-09-30:

After looking into this a bit more I am starting to rethink how I'd like to set up this circuit. My plan as of now is to use smaller, 24V switches with a lower current rating and use the first switch (which I will call the primary) to switch on a relay to pass the higher current power to the printer. I will add a fuse (15 A) between the PSU and the relay for protection. The questions I have about this approach are as follows:

  1. Will the relay I have selected work for this application (BOSCH 0332019203 High capacity relay)? Meaning will it be able to handle the sustained load of the printer running for hours on end (sometimes 24 hrs. or more). I believe it should based on the spec sheet but I am no expert at reading those documents.

  2. Is there a better way to achieve my goal to control the printer and peripherals? Should I consider a solid state relay or other device?

I have attached my new diagram and a screenshot of the relevant relay specs in case the link doesn't work.

Revise wiring diagram

Relevant relay specs

  • \$\begingroup\$ What is this current "AC INPUT W/SWITCH"? Is it a box with a switch on it? What is its current rating? \$\endgroup\$
    – vir
    Sep 25 at 20:02
  • \$\begingroup\$ It is a power socket with a switch. Current rating is 10A @ 250V. The Model number for the switch is AC-14-F1. \$\endgroup\$ Sep 25 at 20:06
  • \$\begingroup\$ What is the current draw of the printer and the LEDs? \$\endgroup\$
    – vir
    Sep 25 at 20:13
  • \$\begingroup\$ Printer Current is unknown. The specs from the manual simply states "Power Input: 110V/220V AC, 50/60 Hz" and a Rated power of "400W". LEDs Current will depend on length chosen But my upper bound for that is 2A. The Fan current draw is 1 Amp. \$\endgroup\$ Sep 25 at 20:44
  • \$\begingroup\$ 16.7A at 24V is 400W, so you will need a different or additional power supply to run an additional 60W of accessories at the same time. \$\endgroup\$
    – vir
    Sep 25 at 20:48


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