Computing max VOC

[ksJoe]

I ordered a pallet of Hyundai 305w panels (HiA-S305HG). My first project will use a dozen of them, and I think I need to split them into two strings of 6 serial panels to stay under the 500v limit of the EG4 aio controller I'm looking at.

From the spec sheet,
VOC is 39.42
Temperature Coefficient of VoC is -0.306

Lets assume Kansas gets down to -13f (-25c). The manual doesn't specifically state it, but I think the VOC is computed at 25C?
I understand the math for the theoretical max VOC at that temp is: 39.42 * (1.00306 ^ 50) = 45.93

So with 2 strings of 6, temp ranging from -25c to 50c, VOC would range from around 198-276, which fits nicely on EG4's 120Vdc~450Vdc, 500VOC

Did I get that right?

 

[Danke]

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[LakeHouse]

It's a little simpler than that, but your answers not far off. No exponent needed, just multiply the Temp Coefficient by the temperature range, so -0.306%/C * -50C = 15.3%
So the VOC = 39.42 * 115.3% = 45.45V

 

[LakeHouse]

I ordered a pallet of Hyundai 305w panels (HiA-S305HG). My first project will use a dozen of them, and I think I need to split them into two strings of 6 serial panels to stay under the 500v limit of the EG4 aio controller I'm looking at.

From the spec sheet,
VOC is 39.42
Temperature Coefficient of VoC is -0.306

Lets assume Kansas gets down to -13f (-25c). The manual doesn't specifically state it, but I think the VOC is computed at 25C?
I understand the math for the theoretical max VOC at that temp is: 39.42 * (1.00306 ^ 50) = 45.93

So with 2 strings of 6, temp ranging from -25c to 50c, VOC would range from around 198-276, which fits nicely on EG4's 120Vdc~450Vdc, 500VOC

Did I get that right?

On the hot end, your panels may get hotter than 50C on a hot, sunny, calm day. Plan for more like 70C, and check that your Vmpp is still above the minimum for the SCC. I would try to get something like 10-20% above the minimum for the SCC, and in your case you should be fine.
I get: Vmpp at 75C = 27.5V.
27.5 * 6 = 165V, which is still above the minimum of 120V.