I have a project that I have been working on for a couple years. attached is an image of the board that I have designed, and the enclosure that it goes in.
I am thinking of bringing the mains into the board to get rid of the current 12v 5A power supply, and creating traces so that I can clean out those wire busses that you see (like running the incoming AC to the output side of the relays). I would like to make the enclosure a bit smaller as it is 20in x 20in x 8in deep. the 3 contactors are probably not going anywhere, so I have to account for them, but I would like to make it much cleaner inside there.
Looking at the photos, my first impression is that it is not necessary.
Yes you can save a tiny bit of wiring by running a mains busbar under the relays. 4 or 8 screw terminals? Not enough savings to make it worthwhile to me.
If you attempt to design your own 12V 5A supply onto the board you will make it really complex. I predict that you will take 2 iterations to decide to put it onto a separate board and that is right where you started except you just learned how to design a supply.
