Can we get an off grid mode?
The recent thread about DNO imposed restrictions on inverter output has made me wonder if Sunsynk could offer an off grid mode on their existing hybrid inverters.
Specifically, add a mode that allows grid and load to be decoupled even when grid is available i.e. "decoupled" mode and also add, "passthrough only" and "pass through + charge only" modes.
When the battery sits above a defined SOC the inverter would always run in decoupled mode i.e. loads are fed by a combination of battery and solar with excess solar charging batteries, where there is excess solar the MPPTs are used to limit solar output (as the inverter already does) i.e. inverter is running as in off-grid configuration.
When the battery drops below a defined SOC the inverter switches to either pass through or pass through + charge only mode. Choice of mode here would depend on the timer settings such that pass through only is enabled during day tariffs times and pass through + charge only is enabled during cheap rate tariff times.
In order to ensure that the inverter can't inadvertently feedback to the grid in (due say to some fault in the MPPT circuitry) when in pass through + charge only mode the inverter would always revert to pass through only mode if it sees any solar available. Note that this is a bit of "belts and braces" approach to appease DNO concerns around unexpected grid feed back in failure mode.
Note that "Pass through only" refers to AC side only i.e. DC side can still charge battery from solar as inverter is decoupled by relay between DC/AC converter and grid/load ports.
Any views on this?
Yes I think understand, my point is that it requires a manual intervention to restore the grid. The point in my original post is that the inverter already has all the relays necessary to automate that switch over, in theory we just need the SW mode adding to support it.