I reached out to Tesla concerning the RS-485 port and here is both my question and their response:
I also reached out asking about the wiring protocol since up to four Gen 2 units could be junctioned to a single breaker but the Gen 3 manual wants a separate breaker for each unit. They confirmed that each unit will need to be on it's own breaker.
With that I'll be doing a bit of re-wiring. I had setup a junction box already that has three 6-gauge wires (two load, one ground) in a 3/4" conduit running from the breaker then branching off to two wall connector locations. Could somebody help me determine if it would be safe to upgrade that conduit to a 1" conduit with five 6-gauge wires (four load, one ground) for a two connector setup? A grounding block inside the junction box would then split the 6-gauge ground and dedicated load wires will continue on to the connectors. I'd be pulling 40 amps off 50 amp breakers, with possibly going up to 48 amps on 60 amp breakers later.
Alternatively I could just let the junction box serve one of the locations and just run a separate conduit for the other, just figured it would look cleaner running them both through the junction box as long as it is safe and up to code to do so.
This is all inside the garage in a dry location.
Thanks for asking Tesla those questions.
As for the separate breakers... if you are going to load share then you only need one breaker and 1 run that is branched, that is the purpose of the rs485 communications and load sharing. If you are not load sharing then a separate breakers is needed for each WC with it's own dedicated wire run.