Good day to all,

I'm finding that my system is only giving roughly 50% of the capacity of my solar arrays rating in full sunlight?  I'm puzzled as have tried everything!

 

I have the following components:

3 x Axpert King 5KW inverters in parallel (FW U1 71 97)

12 x 315W Jinko Cheetah panels 3S4P on 2 of the inverters (total 3.780KW each)
10 x 415W Canadians 2S5P on the other one. (total 4.150KW)

2 x 3.5KW Pylontech Batteries.

I find that i rarely get more than 2.2 KW per array?  I have checked each string and all is connected correctly.  I'm wondering if there is a setting that might be limiting the solar output of the inverter?

 

Any advice would be greatly appreciated.

31 minutes ago, Twakdaddy said:

12 x 315W Jinko Cheetah panels 3S4P on 2 of the inverters (total 3.780KW each)
10 x 415W Canadians 2S5P on the other one. (total 4.150KW)

How many cells are in the Jinkos and the Canadians? I'm guessing 60 cells and 72 or more cells respectively.

33 minutes ago, Twakdaddy said:

I'm wondering if there is a setting that might be limiting the solar output of the inverter?

It's unlikely. You already have the latest main firmware that I'm aware of.

3 hours ago, Twakdaddy said:

Good day to all,

I'm finding that my system is only giving roughly 50% of the capacity of my solar arrays rating in full sunlight?  I'm puzzled as have tried everything!

 

I have the following components:

3 x Axpert King 5KW inverters in parallel (FW U1 71 97)

12 x 315W Jinko Cheetah panels 3S4P on 2 of the inverters (total 3.780KW each)
10 x 415W Canadians 2S5P on the other one. (total 4.150KW)

2 x 3.5KW Pylontech Batteries.

I find that i rarely get more than 2.2 KW per array?  I have checked each string and all is connected correctly.  I'm wondering if there is a setting that might be limiting the solar output of the inverter?

 

Any advice would be greatly appreciated.

Hi 2,2kw X 3 =6,6kw.

Is your load ever more than 6kw? 

Your batteries can only take 3,5kw and should be fully charged by 10am. So unless you get more batteries or time more loads to run when the sun is high your pv panels will only produce enough to match your load.

Maybe you could post a picture of your usage at midday?

 

 

@Coulomb,  Thanx for the reply.  With regards to the cell count, that is correct. 60 on the Jinko's (3S) and 72 on the Canadians (2S)

@Buyeye Thanx for the reply.  These my whole house runs through the system so I push the load to well over 10KW when the sun is shining.  I'm using ICC to monitor things so I can clearly monitor the load, PV, battery and Grid power.  I'll post a picture later today at Midday

Edited October 11, 20214 yr by Twakdaddy

@Twakdaddy the wiring sounds OK, I've just learned to check the basics first then look for the rare. 

@Buyeye 100% I agree.  Im pretty sure I have the bases covered with regards to wiring.  Im going to increase cable size from 6mm to 10mm between inverter and combiner box to see if this helps at all? The fact that I have 3 x arrays with different panels giving same results would make me think it may be inverters as they are all obviously running on same settings.  Ill post settings later with picture.

Hi Guys,

 

Here are the pics.  You can see the load clearly exceeds the PV supplied.  i have also attached pics of each inverters PV at around the same time.  The arrays are 3.85Kw x 2 and 1 x 4.15Kw.  The sun is roasting today and directly on the panels.

40 minutes ago, Twakdaddy said:

Here are the pics.  You can see the load clearly exceeds the PV supplied.

Yes, indeed.

Are the three inverters connected as three phase, or all in parallel on one phase?

Quote

i have also attached pics of each inverters PV at around the same time.

I notice that the three inverters are all drawing about the same from PV, within 3% of each other. Even though one has 8% more PV available, in theory.

Is that always the case?

Quote

The sun is roasting today and directly on the panels.

Of course, a really hot day isn't the best for PV production, as panel voltage decreases with increasing panel temperature. But I think you should certainly be getting an extra 25% or so from the panels (i.e. about 80% of nominal power, or around 3.1 - 3.3 kW). Certainly at least 2.9 kW (75% of nominal) on a roasting hot day, assuming no clouds, good tilt, and good orientation (northward facing).

I'm starting to suspect a bug with paralleled Kings; perhaps the master works out that it needs say 2.4 kW of PV to match its output, and tells the slaves to draw the same. Can you check the load on the master: is it getting close to a third of the total load, or perhaps a little less, closer to 2.4 kW in this case? Or if you are in a three phase configuration, perhaps the load on the master's phase happens to be typically lower than the others?

That would mean that the master is only getting some 24% of the total load. IF (a big IF) this is the case, some rearranging of the output wiring to share the current better might help. You do have significant loads there, so voltage drops across cables could be significant. Though I think that (presuming single phase operation) the current sharing cables are supposed to overcome that to some degree.

Edit: The photos of the screens were taken at slightly different times. In the ICC photo, we can see that the first two MPPTs are sending 45 and 48 A to the battery bus; that's a ratio of 1.0677, so 6.7% difference. So it looks like the PV power isn't all that well matched after all. Besides, each machine should be using enough PV to supply the load and charge the battery if needed.

What is setting 16 (Solar Energy Priority), for each machine?

Edited October 11, 20214 yr by Coulomb

@Coulomb The inverters are connected for single phase operation.  The inverters are always very closely matched with regards PV output which is strange to me as they have different arrays, The Canadian panel inverter is not clearly higher as I would have expected?  I tried making the Canadian panel inverter Master to see if this changes anything but still the same.  With regards to the master load, Ill take notes tomorrow midday.

Did you manage to fix the problem?

I have the same issue. 12x 360w panels and only uses max 2.2kw from panels. It never used to be like this, only recently. 

Hi Wynster.  

 

Im afraid not.  I have upgraded fw to latest.  Changed all wiring to 6mm. It seems odd though that the one array that has different panels and higher rating out puts more or less the same as other 2 arrays.  I have noticed that the inverters do sometimes jump to 3.5kw pv for a few seconds then jump back to around 2.3kw... 

Perhaps a silly question, but have you made sure all panels are clean and not shaded. If a bird craps on just one panel, it can bring production down rather significantly.  
I saw a video on boobtube a few days ago where a man had a guy wire (supporting his TV arial) casting a very thin shadow over one or two of his panels. His output had dropped by 30%!! 

Just a thought… 🤔

Hi Gandalf. Thx for the input, much appreciated. Yes 100% clean and full sun.  I have been monitoring over a year now.  Cannot get near 3kw constant pv out of any of the 3 arrays.  Wiring etc has been rechecked 100 times...

Oh one more thing same results from 3 separate arrays on separate inverters...

Wait a minute. You have two Pylontech’s that are limited to a certain amperage (70A or so). Maybe via your communication cables the batteries are telling the inverters to keep the amps down so as to not overcharge the batteries. 

I have an ICC PI controlling my setup.  In the icc software i have a limit set on the charge current for this reason.  However I have turned on 12kw load on fully charged battery to test the pv and it seems to be limited.  I will contact icc t hear if this could be the issue.  Thx for the feedback, appreciated.

On 2022/01/13 at 3:44 PM, Twakdaddy said:

I have noticed that the inverters do sometimes jump to 3.5kw pv for a few seconds then jump back to around 2.3kw

I have 3 Kings in parallel and have similar issues in the past.

In my case it was related to heat.  The SCC has a control loop that derates its output when the SCC temperature gets to 87C.  Now that sounds a lot, but when you have high inverter output AND high PV that is quite easily reached.

You can read the relevant SCC temperature by using the Q1 command.  The SCC temperature is in ASCII in bytes 22-24 of the reply.

I resolved the problem by:

a. reversing the fans in the inverter.  The default setup blows the hot air out the bottom, from where it rises and gets sucked in at the inlets again.  Not Voltronics's finest engineering....

b. improving ventilation in my inverter room to reduce ambient temperature.

One disclaimer: this was all on earlier versions (71.8x) of main firmware.  Things may have changed with later firmware, although this code may live in the SCC which has not been updated.

HI Guys, some feedback.  I have added 2 more 3000C Pylontech batteries, so charge current has now doubled.  I have triple checked wiring and ventilation, all boxes checked!  Panels are spotlessly clean but PV out put per inverter stays around 2kw constant.  I get little spikes where it jumps to 3.5kw for a few seconds and then settles back to round 2kw?  Quite frustrating. Any words of wisdom?

Can you post a pic of your inverter settings...I'm not sure if ICC exposes those settings or not? Or maybe jot them down on a piece of paper. From 1 - 34. The devil is in these details...

Hi Steve87, thx for the reply!  please see attached, hope you can read my scrawl?

Without having much experience on the King. I would say that the Devil I have spotted lies in Menu option 16. The manual has a few different options. What I suggest is try these options on the same Solar type of day one by one and watch and see what comes of it. I think you might just find that lost PV somewhere in there...

I would also set number 2 and number 11 to higher than 50A. Because 50A is unfortunately only 2500w on the solar charger. Between these 2 you might just have a solution. Remember in Parallel Ops, each machine will charge accordingly to what is set. The only values that are common are the Float, Bulk, and cuttoff etc. The charger amps need to be set individually on each inverter. 

Hi Steve87, thx for the feedback.  The Pylontech batteries max charge current is 37A each and I have 4, so that is 147A for the 4.  I set the 3 inverters to 50 so gives me 150A.  don't want to go more than that in case I damage the batteries?

 

Ill try the other settings and post the results.  Thx for the interest taken, appreciated!

I see on my system that the Charging current is changing on the inverter. It seems the BMS is in control of that.

If the comms between batt and Inverter is in place this should be the case.

Hi Jacques, I have ICC installed with the new RJ45 cable.  No cables from the pylontechs directly to inverters.  I assume this is correct?  Been running for a year or two now, all good except this issue?