Hi

 

I got a quote for a 5kW sunsynk with four 540W panels

 

looking at the data sheet, the MPPT max current is 11A where’s the panels produce 13A. Did my installer spec the system incorrectly?

No the inverter can now do 13 amps , they just haven't updated the specs everywhere.*edit  if you are only getting 4 panels you are going to be running at a very low voltage , you want to ideally have higher voltage like 5 panels absolute minimum,my personal opinion.The mppts are the most efficient at 370v+-

Edited February 5, 20223 yr by Nexuss

Won’t 13A still be cutting it quite close and running at the design limit?

Just now, MNK1234 said:

Won’t 13A still be cutting it quite close and running at the design limit?

no its absolutely fine the inverter can clip down amps if needed , the most important bit is that you dont go over 450-480v per string so up to 9 panels on a string is fine. I actually have a friend with 8 of those panels on a string on his 5kw sunsynk.

So for the design you need a minimum voltage to ensure it runs effectively. Based on budget this may mean more smaller panels?

Also for less the 9 panels would you still need a combiner box?

8 minutes ago, MNK1234 said:

So for the design you need a minimum voltage to ensure it runs effectively. Based on budget this may mean more smaller panels?

Also for less the 9 panels would you still need a combiner box?

look it will work with 4 panels dont get me wrong ,but the efficiency wil be quite low (ie. watts produced per panel) with 8-9 panels your efficiency is at its peak. So yes more smaller panels will work but only if you get quite a few more . I run 8 -455 watt panels on a string and only operate around 300-350volts  so still under ideal ,9 would be ideal in my case .

No for the 5kw sunsynk you dont need a combiner box as you wont be paralleling any stings (like you would with the 8kw sunsynk)

Edited February 5, 20223 yr by Nexuss

The 540w panels are ideal for the inverter, just right

If it's a case of put 4 now, then do it, get more later. 

Ideal setup suggests 6x-7x 540w panels per mppt, for a total of 12-14 panels. 

There's no combiner box needed, just connect them in series.

Edited February 5, 20223 yr by Nitrious

I have a sunsynk 5kw and planning on installing 12 x 540w. 

1 hour ago, MNK1234 said:

Hi

 

I got a quote for a 5kW sunsynk with four 540W panels

 

looking at the data sheet, the MPPT max current is 11A where’s the panels produce 13A. Did my installer spec the system incorrectly?

 

Sunsynk (5kW) can handle 6600 watts of panels easily, a big advantage when overcast as they will still produced plenty of KWs

Edited February 6, 20223 yr by Pumba

On 2022/02/05 at 6:57 PM, Nitrious said:

The 540w panels are ideal for the inverter, just right

If it's a case of put 4 now, then do it, get more later. 

Ideal setup suggests 6x-7x 540w panels per mppt, for a total of 12-14 panels. 

There's no combiner box needed, just connect them in series.

hi there

I got 12 x 550W C6W 550-MS - from the youtube clips from sunsynk, they refer to the Voc limit. scared to connect 12 as by the looks of it, the datasheet says I will hit almost the voltage limit in string. want to do 6 in a string on mppt 1 and 6 on string on mppt 2.

any advise - shall I rather connect 10 (5 + 5) and not risk it. torn between the STC and NMOT stats?

thanks

On 2022/02/05 at 6:46 PM, Nexuss said:

no its absolutely fine the inverter can clip down amps if needed , the most important bit is that you dont go over 450-480v per string so up to 9 panels on a string is fine. I actually have a friend with 8 of those panels on a string on his 5kw sunsynk.

hi there

 

also have 5k sunsynk

I got 12 x 550W C6W 550-MS - from the youtube clips from sunsynk, they refer to the Voc limit. scared to connect 12 as by the looks of it, the datasheet says I will hit almost the voltage limit in string. want to do 6 in a string on mppt 1 and 6 on string on mppt 2.

any advise - shall I rather connect 10 (5 + 5) and not risk it. torn between the STC and NMOT stats?

thanks

14 minutes ago, francoisj1 said:

hi there

 

also have 5k sunsynk

I got 12 x 550W C6W 550-MS - from the youtube clips from sunsynk, they refer to the Voc limit. scared to connect 12 as by the looks of it, the datasheet says I will hit almost the voltage limit in string. want to do 6 in a string on mppt 1 and 6 on string on mppt 2.

any advise - shall I rather connect 10 (5 + 5) and not risk it. torn between the STC and NMOT stats?

thanks

You can do a 6 plus 6 with no problem. It's when you have 12 in 1 string that your Voc is too high-not when using both MPPTs.

Edited September 21, 20222 yr by Scorp007

In order to determine the max. No of panels , it's necessary to note down the voc of your panel and try not to exceed 400v for all series panels in any string . We have found 500Wp panels of different VOCs in market, some of hi VOC ,while others of higher current . 

9 minutes ago, Riyad179 said:

In order to determine the max. No of panels , it's necessary to note down the voc of your panel and try not to exceed 400v for all series panels in any string . We have found 500Wp panels of different VOCs in market, some of hi VOC ,while others of higher current . 

Why limit it to 400V?

Actually ,It depends upon the specifications of mppt , most of those I have seen is 450v , so taking in consideration the variation in voc  that may occur due to  differences in voltage produced in different seasons which may exceed the 450v . So for safe factors prefered to have +50v as ( margin) .

6 hours ago, Riyad179 said:

most of those I have seen is 450v

This thread is specific to the Sunsynk, which is 500V.

On 2022/09/21 at 10:22 PM, Scorp007 said:

You can do a 6 plus 6 with no problem. It's when you have 12 in 1 string that your Voc is too high-not when using both MPPTs.

take note on hot summer days your inverter will run hot on the DC side - 82'c recorded on inverter management. once it rained and sun comes out it peaks very quick. will rather be careful than push it to the limit. I upgraded to a 8kva now to make sure my string of two 6 x 550w panels strings are now split between two mppts

8 hours ago, francoisj1 said:

take note on hot summer days your inverter will run hot on the DC side - 82'c recorded on inverter management. once it rained and sun comes out it peaks very quick. will rather be careful than push it to the limit. I upgraded to a 8kva now to make sure my string of two 6 x 550w panels strings are now split between two mppts

I have pushed my inverter very hard in the summer and DC temps has never been more than about 65C . Sounds like you maybe had some loose DC cables.