Every submersible well pump I have ever worked on goes like this there is a little 'pumptec' control box:
Then the well guy has one of two twisted cables typically THW (non direct bury has to be in conduit to the well head) or the more expensive cable that is UF single conductors twisted together both look like this:
Breakers are usually a 2 pole 20 & 12 or 10 AWG wire. Sometimes you see #8 on a deep well.
3rd yellow wire that goes to the pump to start it.
The older pump boxes do
not all have overloads, I would look at the installation instructions that come with the "pumptec".
I dont think I have ever seen one on a 30A breaker.
There is also a sticker on the side of the pump controller with nameplate info.
The new ones usually need to run in a special mode the first time to calibrate the overload. Often times 'well guys' try to help and run the wire for me then I have to re do it.
Submersible water pumps have a lot of regional variation so may be different in your area.