Norway said:
I guess what that thing does is have a slightly different plugin for each plug, so if you use a 15A plug, the unit knows to signal 15A. But the coding is in the plug to the "soap", and if you had a 15A plug, but with a 10A fuse behind it, the fuse would blow.
Basically correct. The Tesla "soap" does not sense available current. The maximum (assumed breaker) rating is "coded" by the pigtail (each of which they charge $100 for). There are only 4 variations so coded: 15, 20, 30, 50. (That's what the two-digit code after the "-" means in the NEMA name for the plug: NEMA 14-xx or NEMA 6-xx, etc. And look at the 3rd column in the Tesla graphic of receptacles.)
So, this means you, the user, choose the proper pigtail to plug into the provided receptacle. The receptacle on the wall is assumed to be properly installed and wired for its "xx" rating. Then you connect the pigtail with the "soap", and connect the "soap" to the car. The "soap" ( ok ... enough; it's really an EVSE :lol: ) then sends the proper pilot signal to the car at 80% of the "xx" rating (so that would be 12, 16, 24 or 40 amps). (Not sure what happened to a 40A rating/32A pilot for this EVSE.)
(The "coding" in the pigtail may be done with resistors, as previously pointed out, but I'm not sure if that's how they actually do it.)