10 KW Sytem with a 30 M DC RUN what size DC cable

[globalfirst]

Hi Just Installing a 10KW system Ground mount. The Consumer unit is 50 M Away from the panels. The problem being this would require a 25mm (CSA) AC cable to keep it to the 1% volt drop allowance. This would be about £350.00.
could i instead have a half way point for the inverter housing and have a run of 30m on DC side and 20M on AC side???
Any suggestions on rules and cable sizing on the DC side would be most helpful Thanks.

 

[edexlab]

D.C should be short as possible . Add the £350.00 to the job ?

You can run the Dc further than 30m do the calcs

 

[globalfirst]

yeah thanks i dont know where to find the dc volt drop calcs and sizes if you could direct me thnks will

 

[edexlab]

yeah thanks i dont know where to find the dc volt drop calcs and sizes if you could direct me thnks will

same as you would do for AC but you can also use sunny design which gives an accurate result however I tend to reduce any maximum run calculated to err on the safe side

 

[JD6400]

same as you would do for AC but you can also use sunny design which gives an accurate result however I tend to reduce any maximum run calculated to err on the safe side

Or we tend to use the solar configurator from Fronius , i am sure there are probably even better ones out there you just have to search.
If you find any please post them up , it all helps

 

[globalfirst]

For AC its LengthxAmpsxM/va/thing. devide by 1000 that gives a %
is there a page in bs7671 for DC cables and a link to the sunny design as i cant find thanks will

 

[BruceB]

Both dc and ac generally behave in accordance with Ohm's law.
Here is Sunny Design
SUNNY DESIGN. SMA Solar Technology AG
PS: it is the first entry in google if you search for sunny design
Regards
Bruce

 

[yellowvanman]

I know some aim for 1% volt drop on DC but the DTI guide mentions 3%!