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Growatt 12k unboxing

So sorry, I forgot to mention... I am using all of this equipment in 48v configuration. I see, none of the parameters have changed for the 24v or 12v applications.
 
Take a look at the spec sheet from the box of the Growatt SC 4880-mpv. Note they still have a column for the 150 VOC units, but note the working voltages of the 250 VOC MPVs, especially @24v

View attachment 78216
Quite possibly they use a series connection to up the voltage. For 12V or 24V, you won't have as many series connections in the MPPT as 48V. At least, that's the way I see it taking a wild guess........
 
I'm wondering if it's a typo between the older 150 VOC unit and the new 250 VOC units
 
Ok, I have an updated spec. Sheet for growatt mppt scc. It does have PV operating voltage reflecting values more inline with assumed volts. I will attempt to attach a copy....
 
It's still doesn't make sense to me. At 24v system, how can it be a 250 VOC and only 30-150v input operating (for the SCC on the far right)
 
I agree, and I don't pretend to understand the way all the electronics work together. But, i had hoped this would help, at least a little. Good luck ?
 
The operating voltage is the voltage where the MPPT will operate. The maximum voltage is where the MPPT will blow up if exceeded.

A solar panel has a maximum voltage(Voc), and a maximum power voltage (Vmp).

You want the Voc total of the string to be lower than the maximum solar input voltage on your inverter/MPPT/charge controller.

You want the Vmp total of the string to fall well within the operating voltage of the solar input on the inverter/MPPT/charge controller.

So lets take this growatt highlighted above:
Maximum: 250VDC
Operating:
12Vbat: 15VDC - 75VDC
24Vbat: 30VDC - 150VDC
48Vbat: 60VDC - 245VDC

Now let's look at an example panel:
255W panel
Voc: 37.8VDC
Vmp: 31.2VDC

If you operate the panel far above or below 31.2VDC, then you will not get its maximum power.

So if you run a 12V battery and only care about the maximum voltage you could string 6 panels together and call it a day. It won't damage your inverter, so that's good enough, right? Maybe not. 6 panels has an ideal voltage of 31.2VDC when outputting its maximum 255W. In a string of 6 panels, you'll find the maximum output around 187VDC. If you run the panels at a lower or higher voltage you'll typically get less power out of the panels than is available. So your 12V system will go to its maximum operating voltage of 75VDC. Nothing is harmed, the batteries will still be appropriately charged, but by operating your panels at a lower voltage than their Vmp you are throwing power away.

So while safety requires only that you make sure your Voc doesn't exceed the maximum input, efficiency requires that you make sure the Vmp falls within the operating voltage.
 
My problem was not in understanding the idea and concept of operating voltage, it was in understanding why at 24v the operating voltage was printed in the manuel as 30-100vdc When the VOC, the point at which it would blow up was 250vdc. It appears a new manual places the 24v operating at 30-150v.

The question now is, which do I believe? My array input voltage is 115v, which should have been fine, until I read the 30-100v in the manual.

But which is it, an operating ceiling of 100v or 150? I'd guess the ladder, but one manual says one thing, another another.
 
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