What is a legal way of hooking cooling fans to the power board?
I would look at the power diagrams for a good idea. also, look at your fan and check the voltage, if its 12 volts you can just wire it in to the PDB with the correct gauge wire of course.
If you are asking about Victor cooling fans, the manufacturer recommends that they be wired to the power input on the side of the Victor. Any fans you add to the robot other than those for speed controllers need to be wired to a dedicated 20 breaker on the PD. This is turn may be wired to a terminal block to distribute the power to the fans. Only one wire per Wago terminal is allowed and it should be no smaller that #18.
So if you are using more than one fan, you don’t necessarily need a breaker for each one. One breaker can be wired to a terminal block of some kind, and several fans wired to that.
Don,
Since the fans use so little current, the robot rules do allow you to wire multiple fans in parallel. Most often that is done with a terminal block, soldered and insulated or wired to a custom circuit board/protoboard. The only time I have seen a need for multiple fans was a team that decided to enclose all electronics in a lexan box. They made provisions for the fan wiring on their custom circuit board. The entire electronics came out as a unit with a massive connector on one side.