Max String Size

[Bshuman]

I've had 3 different responses from the manufacturer and from the sales/design group of a solar wholesaler. The question is simple.

Solaredge 7600a-us inverter
24 soleredge optimizers P400
24 Astroenergy 310W modules ( 2 strings of 12 )
Combiner Box

Solaredge states max string length of 25 optimizers on an inverter

?? Does the combiner make 2 strings of 12 into 1 string of 24??

I want to add 2 more modules to each string. The last answer was in a chat line to Solaredge. Answer, "Yes you can as long as the wire length is less than 1000 feet. But, you should call another number XXX-XXXX to make sure. My second answer was, "We can't advise on design." That came from the number the chatter provided. The third, "Here's a quote but we're not sure, you'll have to call Solaredge."

 

[ggunn]

I've had 3 different responses from the manufacturer and from the sales/design group of a solar wholesaler. The question is simple.

Solaredge 7600a-us inverter
24 soleredge optimizers P400
24 Astroenergy 310W modules ( 2 strings of 12 )
Combiner Box

Solaredge states max string length of 25 optimizers on an inverter

?? Does the combiner make 2 strings of 12 into 1 string of 24??

No. It would still be (2) strings of 12. Note that the published maximum string length is not module specific; with your modules your maximum string length is 19, 18, or 16, depending on the inverter and service voltage. Look at the Maximum Power per String.

 

[Bshuman]

Thank you. I just needed verification. I’m only lean by 9kwh in covering my usage on average

 

[Grouch]

If I could please follow up with a related question, just want to make sure I'm understanding the optimizer spec sheet:
it's 6000 watts max per string (let's ignore the 6500 higher max). and also a max of 25 optimizers per string (let's say it's an inverter connecting to a 208 volt, 3 phase grid). To be able to use a max of 25 optimizers, the solar modules cannot exceed 240 watts each? Not that I would bring it to the threshold, just curious if I have the math right.

 

[ggunn]

Yes. The maximum string length by module count and the maximum Watt limit are there for different reasons. Either establishes an upper limit on string length depending on which you run into first, all though the Watt limit is a bit "softer", i.e., if you go over by a few Watts it isn't a problem.

 

[Grouch]

Yes. The maximum string length by module count and the maximum Watt limit are there for different reasons. Either establishes an upper limit on string length depending on which you run into first, all though the Watt limit is a bit "softer", i.e., if you go over by a few Watts it isn't a problem.

Great, thanks.