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Grid power offset

ScottishBadger

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Joined
Nov 19, 2022
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Hi folks.
My UK domestic single-phase system is fairly complex (to me!) and I am working through various issues with it, one problem at a time. I've attached a schematic which may help...

Basically, the two solar inverters and the Puredrive 10kWh storage system work perfectly, all my problems revolve around the Solis RAI charger unit.
When the Solis RAI system is in-use, it is programmed to charge from the grid using cheap-rate power at a certain time (00:30 to 04:30), the Puredrive is set up exactly the same and both systems do indeed charge from the grid at the set times. The problem is that the Solis does not fully charge its battery due to low temperature, so for some reason the Solis continues to charge outwith the scheduled charging time even though there is no solar production for it to sense and no load placed on the grid supply as the Puredrive is now supplying the house. As a result, it draws power from the Puredrive, which I do not want it to do.

I think this is happening because the ACREL meter is much quicker reacting to minute changes in power flow to and from the grid (we're talking around 50W) than the Puredrive's CT clamp sensing, and as a result the Solis is seeing power going out to the grid and starting charging before the Puredrive is actually adjusting its output in response to its own Grid CT clamp. The Puredrive now picks up on the demand from the Solis and increases its own output to meet demand, resulting in the Solis using power from the Puredrive to complete the charging of the second storage battery.

I am sure I can "fix" this by offsetting the "grid set-point" of the Solis, but I can't find a way to do it - either in the badly translated ACREL paperwork or the Solis manual. (I can do it easily with the Puredrive, but I want to leave it set at 0W set-point as the primary power source and only have the Solis kick-in when demand reaches say 75W from the grid). Can anyone help with how I can adjust either the ACREL meter or the SOLIS RAI to give me this 75W offset, please?
 

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Hi folks.
My UK domestic single-phase system is fairly complex (to me!) and I am working through various issues with it, one problem at a time. I've attached a schematic which may help...

Basically, the two solar inverters and the Puredrive 10kWh storage system work perfectly, all my problems revolve around the Solis RAI charger unit.
When the Solis RAI system is in-use, it is programmed to charge from the grid using cheap-rate power at a certain time (00:30 to 04:30), the Puredrive is set up exactly the same and both systems do indeed charge from the grid at the set times. The problem is that the Solis does not fully charge its battery due to low temperature, so for some reason the Solis continues to charge outwith the scheduled charging time even though there is no solar production for it to sense and no load placed on the grid supply as the Puredrive is now supplying the house. As a result, it draws power from the Puredrive, which I do not want it to do.

I think this is happening because the ACREL meter is much quicker reacting to minute changes in power flow to and from the grid (we're talking around 50W) than the Puredrive's CT clamp sensing, and as a result the Solis is seeing power going out to the grid and starting charging before the Puredrive is actually adjusting its output in response to its own Grid CT clamp. The Puredrive now picks up on the demand from the Solis and increases its own output to meet demand, resulting in the Solis using power from the Puredrive to complete the charging of the second storage battery.

I am sure I can "fix" this by offsetting the "grid set-point" of the Solis, but I can't find a way to do it - either in the badly translated ACREL paperwork or the Solis manual. (I can do it easily with the Puredrive, but I want to leave it set at 0W set-point as the primary power source and only have the Solis kick-in when demand reaches say 75W from the grid). Can anyone help with how I can adjust either the ACREL meter or the SOLIS RAI to give me this 75W offset, please?
That would solve the problem but I don't think there's an 'easy' way to solve it - the Acrel just reads the values so it's not really there to be tweaked, the Solis should allow this but they haven't really considered allowing an import offset it seems, though there is an export setting that allows steps of 100W of export under EPM settings. Judging by what you have available is it worth allowing the Puredrive to take up most of the household load and then allow the Solis to make up the difference instead if that's possible? The problem may then become the opposite where they fight with each other to satisfy the requirements or each other since they have no notion of priority...
 
Yes, that's pretty much what's happening at present I think. I need to think more about the way it's all inter-acting at present. Wishing I'd never bought this Solis unit to be honest, it's been one thing after another, not helped by the installers.
 
Late to the game here but -
I was SOLD on the Ecoflow SHP2 and the new Delta Pro Ultra batter and inverter. Plug and play. Install the SHP2, plug in the battery and away you go...
Until I found out that the SHP2 is only a 12 circuit sub panel... Not a whole house solution...
So back to the drawing board.

1) I don't have solar yet and I have no intention of getting it so it can be grid tied.
2) I wanted a battery back up system to cover my whole house - but programmable to be selective on what I power at the time of need...
3) that battery backup would also serve as a time of use offset on a daily basis.

What was perfect about the Ecoflow is that nothing went to the grid. If I added solar or wind or even a generator... Any power going in went to the batteries. Any power going out of the batteries only went to my use, not the grid...

But only 12 circuits... Not the whole house..

Anyone have anything installed that could handle 24 circuits, be about 6kWh and be under $7k??
 
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