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  • @lavaland 10,400W is NOT a maximum amount of panels you can connect.  10,400W is the maximum amount of DC power that the inverter will use.  As long as ensure that the max voltage of each st

  • I have 12,400W of panels connected to my Sunsynk 8kw inverter BTW 🙂 

  • Here is an example with 400W panels: https://solar.co.za/how-to-size-a-pv-array#cs3

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36 minutes ago, lavaland said:

Hi

A while ago I got a 8kw hybrid inverter.

I currently have several 575W panels on order.

From this page https://www.sunsynk.org/8kw-hybrid-inverter

Its says the Solar Input: Max power input is 10400W

18 panels x 575W = 10,350W

Does that mean that 18 panels are max that I can handle with this inverter right?

It's a little more complicated than that, @system32 post gives a good overview, if you just want a casual overview. 

You would want panels that suit the electrical characteristics of your inverter, as well as their proposed mounting location's weather characteristics, and then azimuth and tilt. The 8K Sunsynk's two MPPTs are quite generous and forgiving.  

If you really want to get into the nuts and bolts of solar panel sizing, I suggest the step-by-step method here, because it covers the first two issues rather well:  https://unboundsolar.com/blog/string-sizing-guide

You will need:

  • A list of your goals: what you want to achieve with the panels (to make sure that your goals are defined);
  • Proposed panel's specsheet (to look up key data regarding the electrical characteristics of the panels);
  • Inverter's specsheet (which you already have the link to);
  • Last 10- 20 years' weather (mainly temperature) data for the install location; 
  • Some information on their mounting (azimuth and tilt); and
  • A spreadsheet works well because it allows you to compare different panels. 

 

I'm using Canadian 415W panels with a VOC of 47.8V and an ISC of 11.14A.

My aim once complete will be to have 36 panels connected as 9S 2P per string giving a total of 14940 kWp

The unusable power during good days is irrelevant to me as the KZN midlands has plenty of bad weather days, where the large kWp will help.

The total VOC per string will be 430.2V and ISC will be 22.28A. I am willing to loose the 2,28A on good days.

You will have to decide according to finances and use case. 👍

 

1 hour ago, lavaland said:

Hi

A while ago I got a 8kw hybrid inverter.

I currently have several 575W panels on order.

From this page https://www.sunsynk.org/8kw-hybrid-inverter

Its says the Solar Input: Max power input is 10400W

18 panels x 575W = 10,350W

Does that mean that 18 panels are max that I can handle with this inverter right?

@lavaland 10,400W is NOT a maximum amount of panels you can connect. 

10,400W is the maximum amount of DC power that the inverter will use. 

As long as ensure that the max voltage of each string is below the max of your inverter (8kw Sunsynk I assume) you are good, the MPPT will control the amperage coming from the strings to ensure that it stays below it's max. 

It is quite common to "over watt" the panels, especially in lower solar radiation countries so as to ensure good production even on overcast days. 

Keith talks about this on the Sunsynk Youtube channel.

 

4 hours ago, TimCam said:

The total VOC per string will be 430.2V and ISC will be 22.28A. I am willing to loose the 2,28A on good days.

Isc or Imp? The 8kW Sunsynk should be taking 22A per MPPT, and produce max power oprating normally at Imp. So no real sacrifice. Isc is peak current under short circuit or fault conditions. But the inverter can handle 22.28A.

6 hours ago, Muchachos said:

I have 10,880W of panels connected to a SunSynk 8K inverter. 
 

The PV production graph seems to table top at 9KW.

image.thumb.jpeg.38e7654b8cf514c5b4fff658d61854f4.jpeg

I this the maximum I can get from the inverter?

Go into your settings on the inverter and check that you set your array size to 11kw . I think it may be on 9kw by default.

10 minutes ago, Nexuss said:

Go into your settings on the inverter and check that you set your array size to 11kw . I think it may be on 9kw by default.

The capacity of the plant is currently set to 10,800. 

Max Solar Power(1000 ~ 12000W) is also set to 10,800

Edited by Muchachos

3 minutes ago, Muchachos said:

The capacity of the plant is currently set to 10,800. 

Max Solar Power(1000 ~ 12000W) is also set to 10,800

If your array size is set correctly you are most likely maxing out the amps on that MPPT. On that graph you posted make a new graph but select the PV amps so we can see the max amps.

26 minutes ago, Muchachos said:

It does not like the MPPT is hitting the 22A limit. Below are the graphs.

 

image.png.294884a60ad11f4855fd15b8bf6a0bbf.png

image.png.4989e4269548a37d8164f024b1885bac.png

Do you have enough places for the power to go?

Battery charge amps high enough plus enough loads?

When it clips, maybe switch on the oven to see if it helps

27 minutes ago, Muchachos said:

It does not like the MPPT is hitting the 22A limit. Below are the graphs.

 

image.png.294884a60ad11f4855fd15b8bf6a0bbf.png

image.png.4989e4269548a37d8164f024b1885bac.png

ok then my second guess would be that you are maxing the charging amps for the battery/or the battery is full ? is there somewhere for the power to go to ?

7 hours ago, Muchachos said:

I have 10,880W of panels connected to a SunSynk 8K inverter. 
 

The PV production graph seems to table top at 9KW.

image.thumb.jpeg.38e7654b8cf514c5b4fff658d61854f4.jpeg

I this the maximum I can get from the inverter?

The best way to see it topping out is to 1) choose a cloudless day and 2) export to grid (if you can).I suspect your graph was taken on a cloudy day. 

1 hour ago, Nexuss said:

ok then my second guess would be that you are maxing the charging amps for the battery/or the battery is full ? is there somewhere for the power to go to ?

I can export to the grid and the batteries are not fully charged. 

3 hours ago, Muchachos said:

Yeah. I am not expecting so too and the graph indicates that. 

But that flat peak indicates inverter clipping not panels or weather. 

Have you updated the inverter FW? iirc the higher PV amperage only came in a later FW

41 minutes ago, Chris_S said:

But that flat peak indicates inverter clipping not panels or weather. 

I agree . definitely looks like clipping , you can draw a flat line on that 9kw peaks .

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