So, regarding this business with the CCS, the J1772, the adapter, and shock hazards.
- A Big Deal with the Tesla connector, the CCS, the J1772, and any other blame connector between a BEV and the Outside World is that Power Is Not Applied From Outside or Inside until the connector and car are mated. This is supposed to be fail-safe on steroids: Those little bitty pins have pull-ups, pull-downs, and what all, so if one or more of those pins gets disconnected, the power gets removed from both sides, with prejudice. So, nobody's getting shocked here, right?
- In a Tesla, the pins that carry power (the big ones) can be AC; in which case they go to inverters that convert the AC to DC and the DC thus generated goes to the Battery Management System; or they can be DC, in which case the inverters are bypassed and the DC goes straight to the BMS. The choice of whether to do so or not is up to the computer in the car; the computer in the outside box (DC or AC) communicates to the car what's available and the car rejects or accepts based upon what the external computer tells it.
- So, yeah, the CCS happens to have both AC and DC pins that happen to be separate. The adapter can connect them together in some funky way; then, the communications protocol would talk to the outside box. Now, I suppose that at some Electrify America site the CCS box out there (I hesitate to call it a "charger", it's not really that, the charger's actually in the car) could supply AC, through one set of pins; or DC, through another set of pins; but I strongly suspect that it can't do both at the same time. I strongly suspect that there's Great Big Contactors inside an external CCS box that connects AC to the AC connectors; or DC to the DC connectors; and are extremely likely to be OFF as the default state. So, at first glance, looks like we've got a natural, built in MUX of sorts between the adapter and the very likely pair of contactors in the external CCS box.
- Hence, it's not clear-cut at all that an all-in-one CCS box would damage itself or an attached Tesla, so long as the computer protocols are kept straight.