I have a Multiplus 12/1200/50 and am connecting it now to my Lynx. The Victron guidelines suggest 35mm2 as the cable size to use. I do not have any of this and would prefer not to have to buy it. I would like to use 25mm2 (H0VK-7 ofc). the distance is about 1.1 meters so 2.2m round journey.I have done some maths and the approx voltage drop @ 90A is .155 which is 1.3% of 12V and 1.4% @ 100A. So voltage drop is good. However the online guide for the cable indicates a current rating at 30C ‘in pipe in air’, to be 89 A. As the Multiplus has about 90A at full blast taking into consideration 93% efficiency at 1000W / 12V, I am unsure if this cable is enough for the job. Can anyone direct me in this? Has anyone else used 25mm2 cable for this job> Thank you
The DC cable size is based on more than voltage drop. The key issue is ripple current, as the DC is converted to AC, the DC current cycles at 100Hz for a 50Hz AC, which in turn creates a ripple in the DC voltage at the inverter. The inverter has smoothing capacitors to reduce the ripple current and voltage, but to work correctly they need very low resistance on the DC cables. Hence the Victron recommendation. With smaller cables it may shutdown on high ripple voltage, and/or wear out prematurely.
Why don’t you use 25mm² x 2? Personally, I would still buy the 35mm² or bigger.
Thank you for the insight this is indeed important info I’m missing.
Well the 2x25mm2 wont fit and then its awkward on the otherside at the lynx. But thanks for your response. I am buying some 35mm2.