Inverter Sizing
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I have 10.22kW of panels on a 7.7 kW string inverter or a DC to AC ratio of 1.32. So yes, there is clipping. One thing about bright sunny days with clouds and clipping. In the right circumstances, a bright shot of sun between clouds will cause clipping because the solar panels are cold compared to solar panels that have been exposed to the sun all day.
I am not a solar designer and have no East West solar panel orientation design expertise, but on the Solis datasheet, it says "Max DC Input watts 4600" for the Solis-1P4K-4G. There must be some design justification somewhere in your paperwork.
Also, another website said "UK only: Please note, the SOL-4.0-4G-DT is rated at greater than 16A per phase and therefore must be installed as per G59/3 or G99. Select the SOL-3.6-4G-DT for an inverter limited to 16A"
Your inverter can put out 18.2 amps or 17.4 amps at 220V/230V but whatever the G99 is, it seems to be the limiting factor for this inverter.Comment
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I have 10.22kW of panels on a 7.7 kW string inverter or a DC to AC ratio of 1.32. So yes, there is clipping. One thing about bright sunny days with clouds and clipping. In the right circumstances, a bright shot of sun between clouds will cause clipping because the solar panels are cold compared to solar panels that have been exposed to the sun all day.
I am not a solar designer and have no East West solar panel orientation design expertise, but on the Solis datasheet, it says "Max DC Input watts 4600" for the Solis-1P4K-4G. There must be some design justification somewhere in your paperwork.
Also, another website said "UK only: Please note, the SOL-4.0-4G-DT is rated at greater than 16A per phase and therefore must be installed as per G59/3 or G99. Select the SOL-3.6-4G-DT for an inverter limited to 16A"
Your inverter can put out 18.2 amps or 17.4 amps at 220V/230V but whatever the G99 is, it seems to be the limiting factor for this inverter.Comment
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Also, another website said "UK only: Please note, the SOL-4.0-4G-DT is rated at greater than 16A per phase and therefore must be installed as per G59/3 or G99. Select the SOL-3.6-4G-DT for an inverter limited to 16A"
Your inverter can put out 18.2 amps or 17.4 amps at 220V/230V but whatever the G99 is, it seems to be the limiting factor for this inverter.
In your case, G99 type A is for power generation greater than 16 amps and less than 1 MW. In the quote above, Solis is saying the SOL-4.0-4G-DT puts out more than 16amps and should be installed as a G99 type A device. The Solis manual says Current for Protective Device (A) = 25. I gather this means you should have a 25 amp breaker.
If 10 panels are East (10x 40volts= 400 volts) and 10 panels are West and are on different MPPT inputs, then each string would be under 600VDC max, but then there is the total DC power issue.
I didn't answer the clipping/East/West issue because I don't know enough about this.Comment
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Now people have mentioned potential problems, I have seen this very jagged graph right from installation. This is today and does seem wierd that clouds could make this much impact. Any thoughts
today.jpg
There does however seem to be what looks like some clipping going on.Last edited by J.P.M.; 04-15-2021, 07:28 PM.Comment
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Wow. You would get that much of the system shutting down due to just clouds passing by. Now I understand why some Floridians have reluctance to installing solar. There seems to be a lot of clouds on most sunny days here.Comment
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Maybe Javanerd doesn't know that array output is not supposed to be constant if the irradiance is variable.
Seems to me also that with two arrays 180 degrees apart with maybe different shade regimes that different power outputs would probably be expected.Comment
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