new solar pannels 235V 0.0

woodzykiler · Feb 10, 2024

My new/used pannels have been hooked up on the ground (temp) and they output a wopping 9Amps @ 240.6V
The math says i can go the full 118Ft and only lose about 2-3 Volts with 10awg solid copper. Does this seem right?

OzSolar · Feb 10, 2024

That's what I'm getting. Is that Voc? If not you, may want use to use Vmp but it I bet it won't change enough to need to use 8 awg.

woodzykiler · Feb 12, 2024

OzSolar said:
That's what I'm getting. Is that Voc? If not you, may want use to use Vmp but it I bet it won't change enough to need to use 8 awg.

Vmp is 33.9V Voc is 40.9V and i want minimal loss over the 118 Feet the cable has to travel @ Imp 9.43Amps Isc 10.02A

Im useing the higher numbers for the math as i have seen them reach that and then some on higher UV days
where i live i have seen a UV of 11+ in the summer, and this makes my pannels poop out more power then there ratings upwards of 18% more.

OzSolar · Feb 12, 2024

1) To meet NEC code I first size my wire at Imp x 1.25 (It used to be 1.56 but I believe they've backed off on that)

1.25 x 10.02 = ~12.5 Amps.

2) But performance I size my wire at NOC - Normal operating conditions which if not published is around 80% of Imp

9.43 x .8 = ~7.5

#12 is fine in my book.

Keep in mind a fixed solar array will spend very little time at BOTH the perfect angle and the perfect weather, as in hours per year.

My opinion is that many people waste a lot of effort and money stepping up to larger wires for what amounts to no return on investment. YMMV

woodzykiler · Feb 14, 2024

OzSolar said:
1) To meet NEC code I first size my wire at Imp x 1.25 (It used to be 1.56 but I believe they've backed off on that)

1.25 x 10.02 = ~12.5 Amps.

2) But performance I size my wire at NOC - Normal operating conditions which if not published is around 80% of Imp

9.43 x .8 = ~7.5

#12 is fine in my book.

Keep in mind a fixed solar array will spend very little time at BOTH the perfect angle and the perfect weather, as in hours per year.

My opinion is that many people waste a lot of effort and money stepping up to larger wires for what amounts to no return on investment. YMMV

i ran the numbers for my 118ft of line ill need. and if i use a high voltage and low amps (10 or less) i will only lose 2-3 volts at best. the small the wire the more loss ill have, and the more amps vs voltage i run the loss is even greater like in the 10-30 volt range..

new solar pannels 235V 0.0

woodzykiler

New Member

OzSolar

Whatever you did, that's what you planned.

woodzykiler

New Member

OzSolar

Whatever you did, that's what you planned.

woodzykiler

New Member

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