question

Wow, if you want to transfer only 2A over this distance using an AXPK 3G50 Aluminium Earthcable, you loose already 24V.

The only way to compensate this is seting up the MultiPlus to deliver the maximum voltage of 260V.

I have done something similar in Estonia, but only over a distance of 1800m but with 6A, by using a smaller MultiPlus 48/3000 setup to 260V and using only 4 batteries 12V/200Ah), then 1800m of AXPK 4G25 (...and yes, I have bridged two of the conductors to reduce the power loss a little bit, NOT legal, but it works) and at the house a bigger 48/8000 which has a limited input current of 8A with bigger batteries of 60kWh.

This was the cheepest solution in Estonia, to get this done. The Grid provider Elektrilevi has ask for 3 times more.

However, maybe you should think on a 230V/1000V transformer solution (like an Autotransformer) because with even 260V you will be not happy with it.

Thanks Michelle for feedback. You are correct in pointing out that legal issues is part of the problem. You mentioned about your installation that it is "NOT legal, but it works". Well, we have to be very careful about following the law. On the other hand, the state has been very forthcoming in changing the laws when they understood that strict regulation can unnecessarily harm distributed energy production and transmission.

Another point of interest is certainly the economy of the undertaking. When it comes to earthwork, I have been told that in Finland an energy cable for less than 0.4 kV voltage can be ploughed in the same furrow as the fiber cable (which can or should be unarmored). A higher voltage would require digging at a distance from the fiber cable.

Copper versus aluminum is also an economic issue. For us, loosing energy isn't perhaps all that critical, as long as we can transfer energy during critical conditions (when petrol also can be scarce commodity).

Ahhh, you are in my neighbour country.

Jah, the law is in Finland strict like in Estonia.

I have put the two conductors parallel, because it is BEHIND the main switch and fuse of the Grid provider Elektrilevi and nobody has ever gotten this issue because nobody looked into the second box after the first Inverter and the box before the second Inverter.

Question:

How many Ampers do you have to transmit?

Did you mean 3kWh in 30 hours?

Mean you have a load of only 100W?

If you use an AXPK 4G25 or if it exist in Finnland an AXPK 3G25, then with 0,5A you have only a Voltage drop of 12V.

In this case, I would even go with a cheaper 16mm² because the Voltage drop will be then 19V.

I have just bought 280m AXPK 4G25 and payed 890€. 10km cable is not funny at all. Hence my idea, to run the second Inverter as 24/7 charger which allow me to use bigger devices running from the fully charged Battery.

With 6A per hour I get per day up to 33kWh which is enough even for bigger things.

Too bad that the power from the Grid is MINIMAL 6A otherwise I would have lowered it even more.

@Michelle Konzack:

> Mean you have a load of only 100W?

That is how electronics develops and that is what we try to reduce by optimizing energy consumption. Consider this: PC (200W) > Laptop (100W) > Raspberry Pi (5W) > Raspberry Pi Zero (2W) > Raspberry Pi Pico (0.25W). When will that development reach switch and router equipment? Likewise: The most efficient equipment cabinet is the one were heat doesn't leak. And so on.

> How many Ampers do you have to transmit?

This is not a mechanism to provide electricity directly for the equipment in the nearby machine room(s). The aim is to charge the energy storage, the batteries while generating electricity at a distance. During an outage we cannot drive around to a number of machine rooms because of time and petrol constrains.

> If you use an AXPK 4G25 or if it exist in Finnland

Thanks for the useful advise. We do purchase equipment and parts from the Baltic states and have even negotiated about a cable purchase. There is only one manufacturer of energy cables in Finland (REKA) so I'm pleased with the idea of contacting W.EG. Eesti OÜ. They seem to be a member of the Würth group. Let's find out what is practical.

Thanks again Michelle for maintaining this exchange of ideas . Are there other parties who would like to join our discussion?

Finally some discussion about this topic :)

Before creating own thread I like to ask from you, have you already implemented your long distance installation? My installation also in Finland where distances between buildings are often pretty long.

I'd like to double my LFP battery bank from 32kWh to 64kWh but running out of room so idea is move 3x Quattro II 5k system to 300m from main house. Then connection point is also more close the grid connection and I would get more charge power(lover voltage drop). At new location there is good connection around 1,2kA Ik so makes sense to move my largest consumption this is battery charging more close to the grid connection point.

Specially with new ESS input limit functionality GX can optimise maximum charging power without blowing fuses. Cable from that point to house is "only" about 300 meters and AXMK4G50 so voltage drop should be manageable. My base loads are 1-1,5kW and very rarely over 10kW peaks like sauna or woodworking machines.

How you came with 260V inverter voltage as in multiplus & Quattro manuals state max inverter voltage setting is 245V?

Aiyeah...

4G50 for only 300m and 10kW?

Guy, use a standard 4G25 and setup your Inverter to the maximum of 245V.

Oh, my MultiPlus-II allow up to 260V in Battery Mode (I am Off-the-Grid)

My neighbour got a new Grid connection and the transformator support 75kVA while he use only 400V 32A (12,8kW) and they use with 800m only 4G50 which support even 50A over this distance and the Transformator was set to 252V (240V+5%).

My datalogger show clearly, that his Voltage never dropped under 240V.

I am currently digging a 4G25 into the ground (to the transformator above) which is roughly 280m long but I have to get 18-24kW (for three Quattro 24/8000) over it.. (The Voltage drop is roughly 17V @400V with 45A or 18kW), but the cable is 99% used for Feed-In from my two future Fronius if I can not more take the Energy otherwise usefull.

Yeah, I know, Feed-In is the worst case but I want to get rid of the Surplus Energy!

The digging, the cable and the connection box should be payed in 3-4 years.