Hey mate
You could use a variety of connectors, the easiest method would probably be making 2 connectors. 1 for the phase wires (3) and one for the hall sensor configuration (5)
Keeping size in mind, I would suggest using an XLR or IEC connector for your phase wires, and a mini 4/5 pin din for your hall sensors. So even a S-Video in-line plug/socket would work as you could use the 4 pins, plus the casing as the 5th wire.
The main thing to remember is you need ample power(current) handling on the phase wire plug/socket. So make sure you use something fairly heavy duty such as the below. For your hall sensor configuration, anything will suffice really.. So a sealed in-line s-video or 5-pin mini-DIN plug/socket will do the job nicely.
The standard wire size is 14AWG/16AWG for the phase wires, but I would use 12AWG to your socket if possible instead, the hall sensors use small gauge wire around 20AWG
IEC plug
IEC socket
XLR Inline socket
XLR Plug
4 pin mini din (upto 9 pin)
When you make the connections, a good thing to do is use heatshrink tubing over the socket, and a rubber grommet squeezed around that. So when you plug the connector in, the grommet squeezes on the heatshrink tubing and minimizes any water ingress. Seal all of your solder connections with PVA glue or epoxy solution to eliminate and possible short from rain trickling down the cable and you should be good to go
Again, there are quite a few ways to go - but the above connectors in total would not cost you more than say $15-$20
yay
