I've currently got a system which runs 230VAC, 24A through a series of 3 groups of 8 terminal blocks (8A each group, 1A per terminal block), through a relay each (8A), and then through 3 terminal blocks to mains.


simulate this circuit – Schematic created using CircuitLab

I'm thinking about converting this into a PCB, as assembly of the system (including signal wiring to the relays) currently takes about 3 hours.

Is it feasable to run 230VAC, 24A through a PCB? What trace width should I use? What separation should I use?

(I found a lot of partial answers online, but as we're dealing with high voltage and high current I don't trust my own google-fu.)

  • \$\begingroup\$ Certainly! Be aware of creepage and clearance requirements and calculate how wide tracks you need for 24 A without excessive heating. Useful links: 4pcb.com/trace-width-calculator.html, pcbdesign.smps.us/creepage.html \$\endgroup\$
    – winny
    May 14 at 10:25
  • \$\begingroup\$ It depends on which electrical safety rules you must fulfill, and they depend on country where you sell your device. And also how much voltage drop is allowed and how much is allowed temperature rise. \$\endgroup\$
    – Justme
    May 14 at 10:53
  • \$\begingroup\$ Netherlands, but exported to Europe. A drop of up to 10V would be fine, but less is better. As for temperature, it will be mounted in a closed IP66 box. As that lacks any form of ventilation, temperature rise should be kept to a minimum. \$\endgroup\$ May 14 at 11:00
  • 2
    \$\begingroup\$ A drop of 10V is unlikely to be fine. 10V at 24A means that the PCB would be dissipating 240W. \$\endgroup\$
    – Simon B
    May 14 at 15:02
  • 1
    \$\begingroup\$ Note that you will need fusing as the circuit rating changes. You have a 24A circuit coming in, then an 8A relay to a 1A terminal. A common technique is to use specially fabricated bus bars/links made of brass/copper/steel to take care of the high current connections. These are made from sheet that is punched or laser cut so is reasonably economical. Circuit connection can be made by screw clamping and/or have legs that solder to the pcb. You can make them look pretty by dipping them in colored insulation material. \$\endgroup\$
    – Kartman
    May 14 at 18:28


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