Request info on solar 24V cable section

[kirra33]

Hello everyone, I come to ask for your help regarding my installation isolated site, there is 3 panels of 250 watts in 24 volts mounted in parallel, 4 batteries 12v of 100 AH mounted in 24 volts, so 200 AH
An 24 v 3000 hybrid inverter goes from wks brand
I would like to install the inverter at 5 meter batteries to have a view on the control panels, a priori I would have to put a cable of 70mm2, it seems to you correct? In addition, what do you advise me as a safety device, disconnector, fuses etc ...
I thank you in advance for your answers, see you soon

[elephant]

I guess this is the inverter that turns your 24 V DC battery into 230 V AC for use.

3000 VA / 24 = 125 amperes. 25 mm² seem to me sufficient, but I would put my inverter closer: we are close to the starting intensities of the motors.

Now, what would be interesting is knowing your usual average diet and your peak diet. The insulation between 2 conductors must be strictly perfect (by distance) because a short circuit at the terminals of a battery of this capacity is the fire insured.

The disconnector must be a type approved for direct current in order to defuse the arc and its breaking capacity will greatly exceed the 125 amps.

[kirra33]

thank you for your answer elephant;)
So to answer your question about my conso, since I do not do anything like everyone else, I had a maximum budget to buy the material, and in the meantime to make it evolve, it is we who will model our conso compared to the system, in addition I will install a group ... Ideally, it is clear that the inverter should be closer to the batteries, but it will be in my workshop, and if I must intervene, it is necessary that I go out of my house to go see !! In addition I really want to be able to monitor the billboard ... If 25mm2 are enough, it would be good news

[kirra33]

No other reviews ??

[kirra33]

No other reviews ??

[kirra33]

No other reviews ??

[kirra33]

No other reviews ??

[elephant]

and then .... we get impatient?

you said:

in addition I will install a group ...

It seems to me necessary, because the capacity of your battery is about 4800 Wh. Either 4 or 5 days of conso a fridge. And, in winter, there are weeks of greyness where you will royally produce 3 at 500 Wh / day or less ....

[Gaston]

3000 VA / 24 = 125 amperes. 25 mm² seem to me sufficient,

That would be enough in 220V, but probably not in 24V.

Indeed the voltage drop in 10 meters of cable 25mm² (5 meters roundtrip) under 125 A is 1,15V.
There will be more than 22,85V across the inverter ... and 143W losses in the cables, is close to 5%.

To arrive at less than 1V of voltage drop (62W of losses, ie 2%), it takes 35mm² ...

And if we want to fall to 1% of losses, we need 70mm².

By cons, you're right, if the 125A are only used for a few seconds, 25mm² can suffice (and shorten the distance is essential )

[elephant]

Just. Is not there a control deportation system? (with the fashion of connected objects ...)

Casually, it's 9 10 mm diameter! It's starting to look like plumbing!