Solar Panels Cable Size needed from Ground Mount

[clanky]

Hello All,

Currently building an extension to my barn/workshop and before i pour the foundations i want to run some new cables from my ground mount system which will eventually go through the barn and then into the house.

The run comprises of:
i) 25m Buried from the array inverter to the barn
ii) 20m Clipped to cable tray throughout the barn (perforated horizontal)
iii) 18m Buried from the barn outlet to the house CU

So from my limited knowledge:
4000 watt / 230 v = 17.39 Amps
Maximum Volts Drop = 5% = 11.5 Volts

And Im guessing reference method for CCC is:

i) D (number 72)
ii) F (number 31)
iii) same as i)

Before i carry on, am i barking up the right tree?

As ever, any help really appreciated.

Cheers, C.

 

[fourtytwo]

Excuse my ignorance but what's "CCC" and the meaning of the calculations following it ?
Would I be right in assuming this is an inverter rather than a GTI and is it co-located with the ground-mount outdoors ?

 

[clanky]

Correct on the inverter. Thats located underneath the ground mount.

CCC= current carrying capacity. I need to lay some new cables in the ground and want to make sure im using the correct size. I suspect 6mm is sufficient but want to make sure.

 

[pc1966]

There was another discussion here where it was suggested the max VD should be 1-2% or similar.

Partly as cost-effective over lifetime of system (i.e. extra power not lost to I2R heating is more valuable than extra copper at installation time) and partly for good inverter behaviour, though I suspect they are fine at 5% VD.