277 vac Support. Does anybody have experience with it? Tesla can't help me.

[ka9q]

If there is low solar output at our shop, and you turn the HPWC on to 42 amps, it will sometimes crash the inverter. I think it's due to an unbalanced load.

This is quite plausible. Grid tie inverters are required to have all sorts of safeguards to avoid feeding power into a dead or damaged grid. If the voltage or frequency is too high or low, it's supposed to disconnect and wait for it to restabilize before reconnecting. So I can easily believe that three-phase inverters are required to monitor phase imbalance (angles, voltages, etc) and trip if they're too far out of whack.

A single broken primary phase is a very common failure in a distribution network. When this happens, one third of the single phase loads on the secondary are unaffected while the remaining two thirds are connected in series across the remaining healthy phase. This happened once in my neighborhood when an aerial 12kV wire pulled out of a deadend insulator. The burn marks on the iceplant were visible for some time. Fortunately nobody was walking under it at the time.

Does the inverter eventually reconnect after your car has been charging for a while, or does it have to be manually restarted?

This is one thing the Europeans got right -- making 3-phase the standard for AC charging.

 

[MXLRplus]

This is quite plausible. Grid tie inverters are required to have all sorts of safeguards to avoid feeding power into a dead or damaged grid. If the voltage or frequency is too high or low, it's supposed to disconnect and wait for it to restabilize before reconnecting. So I can easily believe that three-phase inverters are required to monitor phase imbalance (angles, voltages, etc) and trip if they're too far out of whack.

A single broken primary phase is a very common failure in a distribution network. When this happens, one third of the single phase loads on the secondary are unaffected while the remaining two thirds are connected in series across the remaining healthy phase. This happened once in my neighborhood when an aerial 12kV wire pulled out of a deadend insulator. The burn marks on the iceplant were visible for some time. Fortunately nobody was walking under it at the time.

Does the inverter eventually reconnect after your car has been charging for a while, or does it have to be manually restarted?

This is one thing the Europeans got right -- making 3-phase the standard for AC charging.

It reboots successfully but sometimes it will take a few tries if you don't derate the EVSE. Yes, Solar Edge inverters are particularly finicky about error trapping. Too low or too high voltage reboots are common since it traps variations that are within SCE guidelines.

 

[Fiver]

A posting on one of these Tesla forums said that North American Superchargers actually consist of stacks of ordinary in-car chargers wired in wye in groups of three across the 277/480V supply. So if these really are the same chargers, a car's internal charger ought to be able to accept single-phase 277V.

Obviously I wouldn't rely on this hunch without confirming it with Tesla, but it does imply that it's possible.

V2 Superchargers were in fact made from stacks of the same chargers inside the original (pre-facelift) model S.

V3 superchargers look similar inside, but obviously have upgraded guts, so those most likely have custom boards inside. They still are made up of stacks of chargers wired up in parallel ( or is it series?)

In both cases the stacks allow individual chargers inside the cabinets to fail, but the cabinet can still output power but at a reduced rate.

 

[Jeepxj]

A posting on one of these Tesla forums said that North American Superchargers actually consist of stacks of ordinary in-car chargers wired in wye in groups of three across the 277/480V supply. So if these really are the same chargers, a car's internal charger ought to be able to accept single-phase 277V.

Obviously I wouldn't rely on this hunch without confirming it with Tesla, but it does imply that it's possible.

the car can take it. the issue is the gen 3 HPWC cannot.

 

[earthwormjim]

Do you really need the HPWC if you're getting to use 277Vac anyway? 32 amps with the mobile charger is almost 9kw with 277Vac, that's already pretty powerful.

I know for a fact the mobile chargers do work with 277Vac, and I know the Model 3 and face lifted S and X can support 277Vac. Even older Model S's can support 277Vac, although they will complain and refuse to charge if your line regulation is above 277Vac, so ymmv.

Here's my Model 3 charging at a lowly 24amps using the mobile charger. I have used this voltage for over a year now. I use a Nema L7-30 outlet, with a pigtail to adapt it to NEMA14-30.

277/480V is Level 3 Charging.

There really is no level 3 charging, what people commonly call level 3 is DC fast charging.

277Vac is still just level 2 charging, because you are utilizing the car's built in charger.