All in One - 2 Solar Arrays

I already have a 3.68kWp solar array with FIT payments. I'm hoping to add a 2nd 2.4kWp array and a GivEnergy All In One with the backup gateway. DNO approval already granted, just waiting for planning permission as it's a flat roof. I notice the gateway only has one input for Solar PV. Any idea how this could be wired? I'm keen for the existing PV to go into the gateway, then the EV charger can be left on it's own submain, invisible to the gateway as connected 'grid side'. This should prevent the battery discharging into the EV when Octopus decide to charge it during the day.
Can the 2nd array just be wired to a submain in the garage? Does the gateway need to know about it, or will it just notice power coming back from the house?
thanks

The AIO is an AC Coupled Inverter so doesn't connect to your solar in the form of DC.

All inputs and outputs from the Gateway are AC.

So if you intend to feed 2 x different outputs from 2 solar arrays then you will need some way of combining those 2 individual AC outputs from each of your Solar Inverters into the Gateway,

Speak to an electrician or your installer on how to do this correctly and safely (and without affecting you FIT Payment meter)

dragon2905 and make sure that the total output from the two solar arrays doesn't breach the limit of what the gateway & AIO can take in via the solar AC connection?

In terms of FIT, if you keep the fit array going through the existing generation meter, you can continue to get paid for it.

If you add the new solar to the same circuit, e.g. it will also go through the same generation meter, then FIT generation payments will need to be adjusted accordingly (percentage of generation paid out based on percentage of solar that is FIT).

As for export, if it's deemed export (50% of generation) that shouldn't need to change. If it's measured export, you may be required to switch from fit measured export to SEG.

TX200 May I ask why in regards to not going over what the AIO can take charge wise? After hitting 6kw wouldn't it just divert rest to grid, the AIO has a hard cap for charge and discharge, anything over that would go to grid would it not?

Jellybaby sorry, I'm not an electrician. I know it is a good idea to check the limits and make sure you conform to them.

@TheDragon (GivEnergy) may be able to advise further

(What is the limit for AC solar connected to gateway?).

TX200 32A, or the MCB can be uprated to 40A

Note, OffGrid will become an issue with larger arrays

dragon2905 Thanks for commenting, but not sure how helpful that was.

Pete Cousins
Your new system is like ours, mostly. Presumably your electrician with just put your new array to the AIO, leaving your FIT on the existing inverter. Since it’s all AC the solar automatically goes to the AIO.
But he does need to put a current clamp on your existing system so that they can be monitored controlled together. Your FIT meter does not have to be touched.

Pete Cousins 32A would be around 7,600W (assuming 240V)?

40A circa 9,600W.

Or at maximum voltage supported by the grid, 253V, 8096W and 10,120W

Obviously some people are seeing grid voltage above 253, which needs fixing locally!, so I assume leaving some headroom might be a good idea?

Pete Cousins perhaps it would be best to leave it to the installers to decide how to do it??

This should give you some insight into one possible method to achieve this......

https://www.youtube.com/watch?v=Lc35UVZqC9c

dragon2905 Sadly quite a few just do standard installs, and don't know about other options.
I had to convince one installer that the AIO isn't a hybrid inverter!!
When I had my solar installed 7 years ago only 1 of the 4 installers knew more than I did. It's worrying really.