start
Selection of PV module : DC / Inerter module :AC
Specification details
Calculate Imax
Select Cable Area with corresponding CCC value
Calculate the deration factor
no
Calculate DCCC
no
Is the CCC of selected
cable greater than DCCC
yes
Find the voltage drop for desired length using area
Is the voltage drop less than 3%
no
Decrease length
stop
yes
Parameters
Voltage drop (to determine length)
The voltage drop in the cable must not exceed 3%
The permissible voltage drop can be calculated by using 3% of V i.e. open circuit voltage
oc
Vd =
2 ∗ L ∗ Isc ∗ ρ
A
here ,
L = route length
Isc = short circuit current of the system
A = area of the conductor
ρ = resistivity of the material
The above equation gives the area of the conductor
Current Carrying Capacity (to determine area)
Find I
max
Imax = Isc ∗ N o.
of
parallel strings
Imax = Isc ∗ N o.
of
inverters
(for dc cables)
(for ac cables)
Find the derating factor
Variation in temperature
Depth of burial
Distance
Due to conduit pipe =
1
√n
(n = number of cables in pipe)
Total Derating factor can be found by multiply deration for above values
DCCC = CCC * Deration factor
DCCC > CCC for a stable system
Choose the conductor area corresponding to DCCC value
References
[1]M. Yahyavi, M. Vaziri and S. Vadhva, "Solar energy in a volume and efficiency in solar power
generation," 2010 IEEE International Conference on Information Reuse & Integration, Las Vegas,
NV, USA, 2010, pp. 394-399, doi: 10.1109/IRI.2010.5558900
[2]IS 1255 (1983): Code of practice for installation and maintenance of power cables up to and
including 33 kV rating [ETD 9: Power Cables]
[3]“What Solar DC Cable Sizes To Use For Your Solar PV System? - Powernsun,” Powernsun, Aug.
13, 2023. https://powernsun.com/what-solar-dc-cable-sizes-to-use-for-your-solar-pv-system/
(accessed Aug. 14, 2024).
[4]C. Nick, “Cable Size for Solar Panels - How to Size Wire for Voltage Drop,” YouTube. Feb. 03,
2024. Accessed: Aug. 13, 2024. Available: https://www.youtube.com/watch?v=sxgntlX4EzY
[5]“Cable Current Rating Derating Factors Explained - ELEK Software,” ELEK Software, 2019.
https://elek.com/articles/cable-rating-derating-factors/ (accessed Aug. 13, 2024).
‌[6]Sustainable Every Day, “Solar DC cable calculation Excel Formula Sheet & cable sizing
Calculation,” YouTube. May 17, 2020. Accessed: Aug. 14, 2024.. Available:
https://www.youtube.com/watch?v=Gm_TCqwdhYw&t=1208s