clanky
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- Reaction score
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Hello, hopefully ive got this right but if someone can check over my maths for me, id appreciate it. Im needing to install a new supply cable from my remote solar array and because of the distance, it needs to go underground for about 35m then into a nearby barn where it will be joined into a JB then run clipped (25m) to a perforated cable tray to another JB, then back underground to the main house for about 15m.
So 4kw solar array : 4000/230 = 17.39A
from table 4D4B, (ref method of D and E) 10mm armoured cable gives 4.4 mV/A/m drop so:
Total VD = (17.39 x 35 x 0.0044)+(17.39 x 25 x 0.0044)+(17.39 x 15 x 0.0044)
Giving a total of 2.68 + 1.91 + 1.15 = 5.74 which equates to a VD of 2.4%
Im assuming of course that theres no penalties for the joints in the two JB's and that the accumulative way ive added up the losses in the separate sections is correct?
I know 10mm is excessive but i have read somewhere (and it has been mentioned on here) that VD should be around the 1-2% for the inverter. Although this is still 2.4%, going to 16mm seems excessive or is that what i should be doing?
Thanks in advance.
C
So 4kw solar array : 4000/230 = 17.39A
from table 4D4B, (ref method of D and E) 10mm armoured cable gives 4.4 mV/A/m drop so:
Total VD = (17.39 x 35 x 0.0044)+(17.39 x 25 x 0.0044)+(17.39 x 15 x 0.0044)
Giving a total of 2.68 + 1.91 + 1.15 = 5.74 which equates to a VD of 2.4%
Im assuming of course that theres no penalties for the joints in the two JB's and that the accumulative way ive added up the losses in the separate sections is correct?
I know 10mm is excessive but i have read somewhere (and it has been mentioned on here) that VD should be around the 1-2% for the inverter. Although this is still 2.4%, going to 16mm seems excessive or is that what i should be doing?
Thanks in advance.
C