Unable to get lock current in a single array - Solark 15 with Tigo TS4 Optimizers

[vnr111]

Hi all, I just commissioned a 50 panel system Solark 15k - all with tigo TS4-O optimizers. I have all the strings working except one string of 9 panels.



The Voltage open circuit is correct - 330V
I tried it on different MPPTs on the Solark but its still not working.
The Solark is unable to lock a current, it keeps scanning the voltage

Tigo claims its a break in the circuit - but how is that possible if its showing correct total voltage? I checked at both the combiner box and inverter.

Any help on anything else I can do to test?

Thanks!

 

[JBoffgrid2022]

Hi all, I just commissioned a 50 panel system Solark 15k - all with tigo TS4-O optimizers. I have all the strings working except one string of 9 panels.

View attachment 181467

The Voltage open circuit is correct - 330V
I tried it on different MPPTs on the Solark but its still not working.
The Solark is unable to lock a current, it keeps scanning the voltage

Tigo claims its a break in the circuit - but how is that possible if its showing correct total voltage? I checked at both the combiner box and inverter.

Any help on anything else I can do to test?

Thanks!

Hello,
I too just purchased 16 Tigo TS4-A-O units for my panels. I haven't installed them yet but I do know they have the ability to monitor the panels using the "TAP" device. Is it possible the system can monitor the voltage in the string? If so, it would seem you may have a bad connection somewhere in your bad string? Maybe a faulty MC4 connector? You said your inverter isn't getting any voltage reading from that string, that is the only thing I can think of.

 

[vnr111]

Hello,
I too just purchased 16 Tigo TS4-A-O units for my panels. I haven't installed them yet but I do know they have the ability to monitor the panels using the "TAP" device. Is it possible the system can monitor the voltage in the string? If so, it would seem you may have a bad connection somewhere in your bad string? Maybe a faulty MC4 connector? You said your inverter isn't getting any voltage reading from that string, that is the only thing I can think of.

Hey yes it was a faulty mc4 connector, it’s just interesting I was still getting the correct OC voltage at the inverter. Couldn’t figure that out.

By the way, something I learned the hard way is the 25% rule with tigo optimizers. I had to rewire all my arrays after learning this….

 

[Mr.Hyde]

By the way, something I learned the hard way is the 25% rule with tigo optimizers. I had to rewire all my arrays after learning this….

25% rule?

 

[vnr111]

25% rule?

25% mismatch rule:

https://support.tigoenergy.com/hc/en-us/articles/203419277-Mix-and-Match-Different-PV-Module-Types#:~:text=The%2025%25%20mismatch%20rule%3A

If more than 25% of the panels in a array report a different current or voltage - ie more than 25% are covered in shade or face a different orientation/angle (which was my issue), then the entire string shuts down to the lowest producing panel in the string.

My issue was I had some east and south facing arrays in the same strings and the entire array wouldn’t produce unless both were getting sun at the same time.

 

[Mr.Hyde]

25% mismatch rule:

https://support.tigoenergy.com/hc/en-us/articles/203419277-Mix-and-Match-Different-PV-Module-Types#:~:text=The%2025%25%20mismatch%20rule%3A

If more than 25% of the panels in a array report a different current or voltage - ie more than 25% are covered in shade or face a different orientation/angle (which was my issue), then the entire string shuts down to the lowest producing panel in the string.

My issue was I had some east and south facing arrays in the same strings and the entire array wouldn’t produce unless both were getting sun at the same time.

Thank you very much for the link.
I think it is very interesting that their examples all references panel differences rather than orientation or shading differences (which would be one of the main points of using optimizers in the first place), but of course shading or orientation can cause the same effect (I guess they do mention "extreme shading" at the top, but then not further down).

Perhaps there are limitations to what the DC-DCs can handle?

My design was supposed to use the new Sol-Ark optimizer and my installer recently re-organized my proposed layout due to a note from Sol-Ark that when using their new optimizer, all of the panels in a string should have the same orientation. I wonder if this is due to a similar constraint.
(also the Sol-Ark optimizers are MIA)

 

[vnr111]

Thank you very much for the link.
I think it is very interesting that their examples all references panel differences rather than orientation or shading differences (which would be one of the main points of using optimizers in the first place), but of course shading or orientation can cause the same effect (I guess they do mention "extreme shading" at the top, but then not further down).

Perhaps there are limitations to what the DC-DCs can handle?

My design was supposed to use the new Sol-Ark optimizer and my installer recently re-organized my proposed layout due to a note from Sol-Ark that when using their new optimizer, all of the panels in a string should have the same orientation. I wonder if this is due to a similar constraint.
(also the Sol-Ark optimizers are MIA)

Here are few more links:

https://support.tigoenergy.com/hc/en-us/community/posts/17555555406483/comments/17566879375635

https://support.tigoenergy.com/hc/e...em-for-different-tilts-angles-and-orientation

https://support.tigoenergy.com/hc/en-us/articles/203419277-Mix-and-Match-Different-PV-Module-Types

it took my installer over a month to come out and fix this open string issue. And then, shortly thereafter I learned that panels that were sitting right next to each other were having completely different outputs, (i.e. some 10%, the output of the one right next to it). And that’s where I discovered this issue was the 25% rule that found all these different Support articles on Tigo‘s website. I sent that to the installer so they could assist me with getting this issue resolved. They initially refused to help me, but after another couple weeks, they came out and fix the issue. But it did require rewiring my entire 50 panel setup.

Per the Tigo support reps, this 25% rule is true of all optimizers regardless of the brand. I also was initially looking at getting the Solark optimizers but couldn’t get them (this was back in October).

They fixed my arrays on Dec 28th and since then I’ve only had 40 mins of sun - but all seemed to be working as it should per tigos monitoring app. We just need more sun!

 

[Quattrohead]

Valuable information, thanks for sharing.

 

[JBoffgrid2022]

Hey yes it was a faulty mc4 connector, it’s just interesting I was still getting the correct OC voltage at the inverter. Couldn’t figure that out.

By the way, something I learned the hard way is the 25% rule with tigo optimizers. I had to rewire all my arrays after learning this….

That's great that you were able to find the problem! Bad news hearing about the "25%" rule tho.... I find it funny that these optimizers have such a low threshold for tolerance. The whole purpose of purchasing them and installing them was to help out with shading / mismatched solar input from the sun. Oh well, knowledge is power! Er, no puns intended lol