Kindred: I wanted to make 2 comments about the Siemens VersiCharge you praised (whose specifications I personally like as well, but I have not yet had a need to buy):
1) From VersiCharge installation and operations manual:
"Nuisance fault: As a leader in electrical technology, Siemens has made the
decision to install 5 mA grounding protection in all VersiCharge devices.
This is the same level of protection that is required in kitchens and
bathrooms of residential dwellings. Some other manufacturers (EVSE and
Auto manufacturers) have selected 20 mA protection levels. Because
Siemens units measure to a more sensitive level, occasional charging
interruption may occur under certain circumstances. See section 4.3 for
a) This is why I much prefer a direct wired EVSE if at all feasible, since an non-GFCI outlet wired EVSE gives you NO GFCI protection at the outlet -- only at the J1772 plug. Note this point is frequently misunderstood!
Although I don't know about all available EVSEs, I haven't noticed any EVSE makers recommending the use of a GFCI breaker -- besides the additional cost of such a breaker it appears "nuisance faults" are too common for EVSEs (note the first VersiCharge manuals recommended using a GFCI breaker, but no longer do), so there appears to be no good way currently to protect an EVSE outlet by such a breaker.
b) It may be that the risk of a shock from an EVSE cable/J1772 plug (via wiring damage and/or water conduction, etc) is small, but I feel better knowing that the shocking current is limited to only 5 ma rather than to 20 ma (Big difference!). I haven't seen posts saying the VersiCharge EVSE has an excessive nuisance fault problem.
2) From Amazon website:
Question: "Do I need to use the amperage adjustment switch on the VersiCharge?"
Answer: "The VersiCharge is shipped from the factory with the amperage adjustment switch in the Max (100%) position. The position is marked by a small black arrow and not the screwdriver slot. The amperage adjustment switch is only used to limit power draw from the vehicle but does NOT allow the charging station to be wired on a smaller circuit than recommended in the installation manual."
My comment: In other words, if your EVSE circuit wiring is thinner than the REQUIRED 8 AWG copper, say 10 AWG copper, you should NOT try to get around this requirement by reducing this "amperage adjustment switch" to the appropriate setting less than 100% (30a), because it is a) too easy for someone in the future to change this switch back to 100% yet not upgrade the wiring (i.e. not realize the wiring is too thin to safely handle the load) and perhaps b) the UL inspectors deemed this switch not completely foolproof in limiting the amperage to less than 100% due to future possible malfunction.
I believe the intended function for this switch is to help prevent the overload of the master breaker. It is an open question if your house has two or more EVs and two or more EVSEs how to best not overload the master breaker when all your EVs are charging at the same time. Making use of EVSEs with an "amperage adjustment switch" set to less than 100% is one approach (while keeping all involved wiring at 8 AWG or better).