I was originally asking about design consideration between using one large inverter or two smaller inverters. Then got onto a bit of the design using one large inverter, but that wasn't really pertinent to the Subject for tha thread.
So I'm re-asking the one-inverter-autotransformer question here in a dedicated thread. Has anyone set up a 230V Quattro with Autotransformer in a US residential setup ?
I'm envisioning a setup as follows :
- Main panel : 100A breaker to Quattro AC1-in
- Main panel : 100A breaker to sub-panel 100A breaker with interlock
- Quattro AC1-out to Autotransformer
- Autotransformer AC-out 120-0-120 hot-neutral-hot to sub-panel 100A breaker with interlock
The interlocked breakers are a back-feed setup for the sub-panel. Only ONE breaker can be on, the other must be off. So the sub-panel is fed by EITHER the 100A from the main panel, OR the AC-out from the Autotransformer. For example
https://media.suthlbr.com/products/images/21125/QO48M60DSGPSTR.jpg
In the US, there can be only neutral/ground bonding point, it must in the main service panel. So the GND relay in the Quattro should be disabled, and the GND relay in the Autotransformer should also be disabled. This way, regardless of whether the sub-panel is fed from the main panel or from the Autotransformer, the neutral/ground bond will only be in the main panel.
The created neutral from the Autotransformer is connected to the neutral bar in the sub-panel, which connects to the neutral bar in the main panel, where the final neutral/ground bond is made.
During an outage, power to the Quattro comes from a 240V generator, using only the L1/L2 hot legs. The neutral is not connected, so it acts just like the connection from the main panel.
Does this all make sense ? Is it correct for a US residential install ?