For SolarEdge with 290W LONGI panels, Do I need to keep same brand in string?

[pkellner]

I've got a 5K inverter with 14 LONGI panels on it. I have room to add 2 more and want to do that. I bought the house with solar and don't have the original receipt. All I can tell from looking at the panel is it has a serial number like this: "LRP503051171000201130".

I understand from my last post here that I need to stick to 290W as more than than will not be used and less will drag the string down.

Do I need to stick to the same panels that are already in the string? If not, what questions do I need to ask (SolarEdge I assume) to find out what panels I can match with.

[bob-n]

=> I'm not a Solaredge expert. Anyone here familiar with Solaredge, please check my logic and math. <=

Before adding to the string, you need to be sure that the SolarEdge won't be damaged by too much voltage.

Each panel puts out a range of voltages, depending on how it is illuminated and how it is loaded. The highest output possible is called "Maximum Open Circuit Voltage". I am assuming that your panels are Longi LR6-60-290M. According to ecodirect's website, these are rated for 38.8V maximum open circuit voltage. If yours are a different model, the maximum output voltage could be different.

The Solaredge SE5000H-US is a 5kW inverter. You may have this model or a different model. According to their website, the input is rated for 480V maximum.

With 14 panels putting out as much as 38.8V, you may already be running too much voltage (543V). Adding more panels to the string seems like a bad idea.

Some arrays include optimizers as well as the inverter. That adds another level of complication. It could be that optimizers are keeping your current array safe.

Here's some additional reading to help you understand these limits:

https://www.solaredge.com/sites/default/files/string_sizing_na.pdf

[wanabee solar]

If you go to the design page you can fill in your system and add whatever you want to see if it can be done https://designer.solaredge.com/sites

[pkellner]

Thanks for the tip, but bummer, I'm not important enough to have access to the page. "NO ACCESS TO DESIGNER"

Does the solaredge monitor app give me enough information about my solar edge model, optimizers and panels that I might be able to put that here and some kind soul with access could plug the in for me?

[wanabee solar]

Its a long time ago but I think you have to register and make an account.

https://accounts.solaredge.com/

[PVAndy]

I've got a 5K inverter with 14 LONGI panels on it. I have room to add 2 more and want to do that. I bought the house with solar and don't have the original receipt. All I can tell from looking at the panel is it has a serial number like this: "LRP503051171000201130".

I understand from my last post here that I need to stick to 290W as more than than will not be used and less will drag the string down.

Do I need to stick to the same panels that are already in the string? If not, what questions do I need to ask (SolarEdge I assume) to find out what panels I can match with.

Depending on SolarEdge model . Panel wattage not voltage determines the number of panels in string. 5250 watts is ok for all versions of SE5k So if 19 290W are in one string, that string is maxed out at 5220 watts. The inverter can handle the addition of 2 panels. You would need to have 2 strings of at least 8 each and use the correct optomizers on the new panels. Panels and optomizers don't need to of same type.

Andy

[pkellner]

Thanks Andy, still a little confused. On the 5K inverter, we currently have 14 panels on one string (that is what the monitor tool shows me). Are you saying that's not right and I should have those on two strings? Just confused when you say "you would need to have 2 strings of at least 8 each". Does that mean I can have 1 string of 16 290W panels? (I think I already have 1 string of 14 290W panels)

[theoak]

Thanks Andy, still a little confused. On the 5K inverter, we currently have 14 panels on one string (that is what the monitor tool shows me). Are you saying that's not right and I should have those on two strings? Just confused when you say "you would need to have 2 strings of at least 8 each". Does that mean I can have 1 string of 16 290W panels? (I think I already have 1 string of 14 290W panels)

When you use the monitor tool, the installer put in your panels, inverters, optimizer information essentially all manually.

(You can scan the bar codes of the optimizers and inverters to make some things easy.)

That also goes with the string configuration. If you are only seeing one string, they when you monitor portal got setup, the installer, I am sure forgot, to setup your strings correctly.

Hence, what you see visually via the web/app may not be a real representation.

Edit: One string though is still supported and possible.

[PVAndy]

Thanks Andy, still a little confused. On the 5K inverter, we currently have 14 panels on one string (that is what the monitor tool shows me). Are you saying that's not right and I should have those on two strings? Just confused when you say "you would need to have 2 strings of at least 8 each". Does that mean I can have 1 string of 16 290W panels? (I think I already have 1 string of 14 290W panels)

First I suggest you ignore much of what is written in this thread. It is based on string inverters without optimizers.
In a SolarEdge system you can pretty much use any mix of panels with the correct optomizers. Currently you have 14 280W panels in one string. This is 14 x 280W = 3920W . Based on 5250W being max on one string, you have 5250 - 3920 = 1330W left you could add to the same string. Doesn't matter if they are 100W or 400W panels. String voltage is optomizer control. It is not related to Voc of modules. All optomizer inject current into string.

Andy

[theoak]

It looks like as per the spec sheet your max string size could be 5250W or 5700W depending on if you have the HD 5k Inverter. It is possible that you have everything in one string. Again, if you have an HD inverter the watts left would be 5700 - 3920.

https://sparc.canto.global/pdfviewer/viewer/viewer.html?v=WebsiteProductPages&portalType=v%2FWebsiteProductPages&column=document&id=jmqge3rffh16d3adq1jals6j54&suffix=pdf