Hi all,

I have a 5kw sunsynk inverter. it can handle 6500w PV.  Can i theoretically have 10x 600w and 2 x 250w?

41 minutes ago, Terminal3k said:

Hi all,

I have a 5kw sunsynk inverter. it can handle 6500w PV.  Can i theoretically have 10x 600w and 2 x 250w?

you can have 11 x 600w 😀

that would be over the inverter limit?
 

1 hour ago, Terminal3k said:

I have a 5kw sunsynk inverter. it can handle 6500w PV.  Can i theoretically have 10x 600w and 2 x 250w?

IMO I would install 5x 600w and 5x 600w to make both mppts work equal, this way inverter will b more efficient and sell the 2 x250w

Edited January 3, 20223 yr by Quwatush Shams (Suly)

 

12 hours ago, Quwatush Shams (Suly) said:

IMO I would install 5x 600w and 5x 600w to make both mppts work equal, this way inverter will b more efficient and sell the 2 x250w

I agree about balancing the mppt's, i would go for lower wattage panels so you are running higher voltage strings . 8-9 panels in a string is where you want to be. With only 5 panels in a string the string voltages are going to be pretty low and not nearly as efficient. I run 16 455w panels on my 5k Sunsynk.

total watts does not matter, just the total volts for the string.

I based mine on winter production

you have to use the same panel in each string, the system will only produce the lower of the two panels

i have not seen any tests where it shows higher string voltage is more efficient, the mppt range is 125v-425v and full load dc voltage range is 240-425v, as per the data sheet

Edited January 4, 20223 yr by Tariq

Why do you have to balance the MPPT's, they are operate separately, each finding their own optimal voltage/current?

When they are working, the voltages and current will be different for both of them, depending on the sun etc. but also what the draw on the load is, they 2 MPPT's will match the load drawn and their voltages/current may be different, this is by design. If you are talking about individual panels in each STRING, then you are correct, but not across the 2 strings, they STRING MPPT's will act independently of each other.

5 minutes ago, Tariq said:

you have to use the same panel in each string, the system will only produce the lower of the two panels

 

@Terminal3k 600W Panels are going to have a very high amperage, 13.5A+ I would guess but you would need to check. 

Max Amperage on the Sunsynk 5Kw is 11A and I think with the new firmware 12A (confirmation from someone please)  so anything above that is  going to be lost as the inverter will raise it's internal resistance to lower the amperage on the panels. 

You would probably be better of saving your money and going with a panel that has a closer to 12A max, maybe Jinko 470w or something along those lines which is max 11.68A.

Voltage is what you need to be very careful with as that can result in smoke and fire. Max recommended on the 5kw is 500V I think (confirm someone please 🙂 ) but most people seem to recommend staying under 450v. 

Jinko 470W are 52.14V per panel so would go max 8 panels per string which would give you 417V & 3760 Watts per string

3760W x 2 =  7520Watts in panels. 

Best would be to have an East/West facing strings so that you get good power in the mornings and afternoons with a lower peak than you would get if all the panels are facing North. 

If you aren't sure if you will need that much power I would suggest getting the installer to install the rails for you for 8 panels but to only install 6 panels onto each string to make it easier to add the extra panels later if you want (just make sure there is enough DC cable length as well)

10 minutes ago, Sc00bs said:

Max Amperage on the Sunsynk 5Kw is 11A and I think with the new firmware 12A (confirmation from someone please)  so anything above that is  going to be lost as the inverter will raise it's internal resistance to lower the amperage on the panels. 

I believe there was talk of this being increased to 13A...

4 minutes ago, FixAMess said:

I believe there was talk of this being increased to 13A...

yes, with a firmware update it has been raised to 13 amps, I have Jasolar 540 watt panels ( limited roof space ), they are rated at 12.97 amps and I have seen 12.94 amps once or twice.

the 600 watt panels will be a waste, as the mppt will clip at 13 amps

Edited January 4, 20223 yr by Tariq

Just now, FixAMess said:

I believe there was talk of this being increased to 13A...

600W Panels are still going to be over that, seems a waste to be paying for power that you aren't going to be able to use 

7 minutes ago, Tariq said:

yes, with a firmware update it has been raised to 13 amps, I have Jasolar 540 watt panels ( limited roof space ), they are rated at 12.97 amps and I have seen 12.94 amps once or twice.

the 600 watt panels will be a waste, as the mppt will clip at 13 amps

540W Panels sound like they would be about the best option then 

 

2 hours ago, Tariq said:

i have not seen any tests where it shows higher string voltage is more efficient, the mppt range is 125v-425v and full load dc voltage range is 240-425v, as per the data sheet

I did this test, I started with 10 panels before i went to 16 so i had some nice data to go on, after increasing the string voltage the watts produced per panel went up substantially. Balancing the mppt's voltage will also help produce more power as they work together. 

Thanks all. 

In the manual it says max DC input of 6500w - so the panels can be more than that? 

PV input voltage is 100v~500v

Mppt range 125v~425v

So I must keep my voltage under 500v for the panels? 

Sorry for my noobness. 

I was going to to 467 volts total, talked to Keith ( ceo Sunsynk ), he said it "should " be ok, but watch for winter time voltage increase due to cold weather, figured if I did fry an mppt, might have a warranty problem, so decided not to take a chance for a few hundred watts more. My advice stick to no more than 450 volts

It shows the nominal PV input voltage is 370 (100V-500V) - it is at this voltage (370) that the MPPT is happiest...The 100-500 V is the operating voltage range.

Be careful with PV input voltages. The start up voltage is 150V and the range is 100V - 425V on Deye Hybrid. Included is a spreadsheet to calculate how many PV's you need for your inverter and your household consumption. Hope it helps

Solar Selection.xlsx

4 hours ago, Terminal3k said:

Thanks all. 

In the manual it says max DC input of 6500w - so the panels can be more than that? 

PV input voltage is 100v~500v

Mppt range 125v~425v

So I must keep my voltage under 500v for the panels? 

Sorry for my noobness. 

The inverter can reduce the amps coming from the panels by increasing the internal resistance of the inverter, the inverter will do this during the normal course of the day when it's battery is full and there is no where else for the power to go. There is a video on the Sunsynk Youtube channel explaining this.

It cannot however reduce voltage so if you get a spike due to cold weather and sudden intense solar you can get a spike slightly higher than the rated voltage of the panels. It is for this reason that it is a good idea to keep the panels well under the max voltage. 

 

On my Sunsynk 5.5kw, I bought 10 of 535W JA panels and it was explained to me that you may not go over the 6500W, that means 3250W per mppt. On my current setup 5 × 535 = 2675w. If I  need more power I can add 1 more panel per mppt to get to 3210W with (49.45V ×6 = 297 V at 12.9A). 

My inverter version 01 can handle 13A, at max 500v but something to remember is that according to the panel data sheet, the voltage is at 25°c so that V will raise quite a bit as the temp goes down. 

9 hours ago, Vaal said:

On my Sunsynk 5.5kw, I bought 10 of 535W JA panels and it was explained to me that you may not go over the 6500W, that means 3250W per mppt. On my current setup 5 × 535 = 2675w. If I  need more power I can add 1 more panel per mppt to get to 3210W with (49.45V ×6 = 297 V at 12.9A). 

My inverter version 01 can handle 13A, at max 500v but something to remember is that according to the panel data sheet, the voltage is at 25°c so that V will raise quite a bit as the temp goes down. 

If you stay within the voltage and current spec of the MPPT, you don't have to be below 3250W per MPPT. You can also go over the 6500W total, if you stay within spec for voltage and current, but there are some other considerations, so I don't recommend doing that. Also, you will never see VOC and ISC at the same time.

Edited January 5, 20223 yr by P1000

@Vaal, you can go over the 6500 watts, the only negative is that except for battery charging, the inverter can't invert more than 5000 watts, the rest will come from the grid, main reason to go over 6500 watts is for winter or cloudy days.

also remember, try not to go over  450 Voc and anything over 13 amps will be wasted due to clipping.

30 minutes ago, Tariq said:

@Vaal, you can go over the 6500 watts, the only negative is that except for battery charging, the inverter can't invert more than 5000 watts, the rest will come from the grid, main reason to go over 6500 watts is for winter or cloudy days.

also remember, try not to go over  450 Voc and anything over 13 amps will be wasted due to clipping.

Thank you. Somebody told me that my calculation of 9 × 535w at 50V voc and 13A, only on 1 mppt string could cause some problems when it is eg. overcast and then the sun breaks through which can cause a spike. That high spikes might come back and kick you in the knee.

My plan was to, at a later stage add more panels on the second mppt.

I changed my plan to use 10 panels at 5 per mppt for time being and see what happens. It is already a bit overkill for my current usage but redundancy is always good. 

@Vaal, what panels are you planning on using

@Tariq it seems like you have some knowledge picking panels for the sunsynk 5kw.  I want to start with about 6000w of panels then add more later - what would be your recommendation for panel selection? you said you're using JA 540W? 

@Terminal3k, my main reason for going with the JaSolar 540 was limited roof space ( cost per watt was a bit higher than a 455 watt panel ) and mine are NW and NE orientation, what about your roof space and orientation ?