UK AC coupled battery inverter CT clamp question

[agsolar]

I'm looking to build a battery storage system in the order of 5-15KWh.
AC coupled to be charged from existing small PV but to be mostly charged overnight on cheap TOU.

I've been looking at a number of inverters e.g Solis and others. Many have either 1 or 2 CT clamps for monitoring solar production or direction/phase of total load in case there is 'spare' power to charge.

My question is on the phase monitoring CT - does it need to be connected to the tail of the import meter, or can it go anywhere ?
The reason is that my house was extended before we moved in. There are two consumer units - the PV inverter is connected to the 'new' CU in the basement and access to the import meter/mains entry is impossible. The charging inverter would be in the same place.

Can these inverters work without CT monitoring, in a sort of manual mode? I.e I'd accept just timed charging. Or possibly, me observing spare PV generation and doing manual top up in the day (guess I would lose a balanced demand though?)

Edit: Ive seen that some folk like @SeaGal and @SteveB123 got CTs working over RS485 to Powerline converters, and Im researching that.

But still interested in knowing the inverters can be configured to work without.

 

[FVScimitar]

AC battery inverters need CT device connected via the inverter tithe Grid Import Live to read data for import/export.

My Solax AC X1 3.6kW inverter is connected this way and charging via solar array, also helps EVSE charge point (Hypervolt 2.0) when ECO is selected Default 6A (1.4kW) for solar charging the AC battery 11.6kW capacity will take up the slack (No Grid Import) when clouds appear and affects the solar power production. When you have great solar conditions I increase the ECO setting from 6 A to 10A.

My solar string inverter and AC coupled battery inverter will provide Max 7kW power .

On Octopus Go TOU tariff for cheap charging at present 7.5p then will be 9.5p from October 2023.

 

[SeaGal]

Can these inverters work without CT monitoring, in a sort of manual mode? I.e I'd accept just timed charging. Or possibly, me observing spare PV generation and doing manual top up in the day (guess I would lose a balanced demand though?)

Edit: Ive seen that some folk like @SeaGal and @SteveB123 got CTs working over RS485 to Powerline converters, and Im researching that.

But still interested in knowing the inverters can be configured to work without.

Such a system cannot work without.

The inverter needs the input from a CT clamp to measure the house to grid import/export. It uses this info to work out:-

a) whether there is energy being exported that it can use to charge the batteries and
b) how much power to discharge from the batteries to fully power the house without exporting your battery energy to the grid.

 

[kommando]

Solax do inverters that export limit based on RS485 feed from a CT fitted to a meter, you can then send the RS485 via wifi to the Inverter using Hyflying EW11's so no long wire run. I use EW11's to make all my RS485 go over wifi and they are reliable as long as you use firmware 1.44.1 or later. Other inverters have that RS485 option too.