I finally got close enough to one of the buck/boost transformers that I see at various supercharger locations to get specs off of it.
As suspected, they added these to reduce the input voltage by about 5% using an autotransformer. My understanding is that the second generation charging circuitry for the S/X (which is what the v2 superchargers were based on) is sensitive to voltages above like 282 ish volts. They kick offline if the utility voltage is too high.
Then the utility provides 480/277 three phase (and be inverters are connected phase to neutral and so nominal voltage is 277v), but the utility may fluctuate up and down by like 5%, so that created an issue sometimes. I think this is also why they removed from the Wall Connector instructions the allowance to hook it up at 277v.
So I am tempted to install Wall Connectors at commercial locations using small single phase 277v autotransformers with similar specs to these rather than stepping all the way down to 240v or 208v.
These are the Washington Square Urban Superchargers off 217 in Portland Oregon just for reference. Also, I am thinking that the urban superchargers are different from the long haul superchargers in that the twelve 12kW rectifiers in them don’t have switching in them to let them latch on to either DC bus (for the two cars). They are hard connected to a single bus (less things to fail). Then they also probably don’t need as large of conductors to the vehicle drop cords as the long haul superchargers.
Anyway, just putting this info out there in case anyone else is interested! Making sure it is on the google search cache for future folks!
As suspected, they added these to reduce the input voltage by about 5% using an autotransformer. My understanding is that the second generation charging circuitry for the S/X (which is what the v2 superchargers were based on) is sensitive to voltages above like 282 ish volts. They kick offline if the utility voltage is too high.
Then the utility provides 480/277 three phase (and be inverters are connected phase to neutral and so nominal voltage is 277v), but the utility may fluctuate up and down by like 5%, so that created an issue sometimes. I think this is also why they removed from the Wall Connector instructions the allowance to hook it up at 277v.
So I am tempted to install Wall Connectors at commercial locations using small single phase 277v autotransformers with similar specs to these rather than stepping all the way down to 240v or 208v.
These are the Washington Square Urban Superchargers off 217 in Portland Oregon just for reference. Also, I am thinking that the urban superchargers are different from the long haul superchargers in that the twelve 12kW rectifiers in them don’t have switching in them to let them latch on to either DC bus (for the two cars). They are hard connected to a single bus (less things to fail). Then they also probably don’t need as large of conductors to the vehicle drop cords as the long haul superchargers.
Anyway, just putting this info out there in case anyone else is interested! Making sure it is on the google search cache for future folks!