Adding Extra Pv Panels

[Phil36]

Hi, I'm a time served roofer and have just completed a series of training courses in France to be an approved Solar PV installer, which includes the electrical installation.

Already I have a customer requesting that I add an extra two panels, (which he has acquired) to his existing installation, not a problem other than he has 12 x 240w panels already installed onto a 2850w inverter (NG3000TL), so its already just above capacity with 2880w.

If another 480w were added what effect will it have on the inverter?

Thanks in advance

 

[NozSpark]

How would a course held in France enable you to comply with UK regulations??

 

[steptoe]

He is in France by the look of his location....

 

[NozSpark]

He is in France by the look of his location....

Can't see that on the android app sorry

 

[steptoe]

I can see it fine on my Sony SP android.

 

[NozSpark]

In the app or through your browser?

 

[binky]

1/ you need to check string voltages a re within capacity of the inverter

2/ whilst we work on peak outputs, in reality systems rarely work at that level, so you might get away with it! Sizing inverters at 80% is acceptable

3/ I'm not familiar eith that inverter, just generally check the spec.

I suspect it will work OK, but customer needs to understand it may shut down on the sunniest, brightest days.

 

[Phil36]

Thanks binky, I take it that inverters have an overload protection then!

I didn't want to add the panels, then 3 months down the line the inverter has given up the ghost.

 

[binky]

Hmmm sort of, depends on make. Most will take a higher voltage than they can actually process, but you really need to check the spec of inverter (max DC voltage) and panels Voc. Eg if you have 10 panels outputting Voc 30V then highest voltage the inverter sees is 300V. Most panels output Isc (short circuit ampage) around 8Amps, so for 10 panels as a singe string you are looking at 300V and 8Amps, however if the same 10 panels are wired as a two stings then the numbers would be 16A and 150V. As long as you don't exceed max DC voltage or Ampage from the panels to the inverter it will work. Most inverters work upto around 550 / 600V. Ampage varies with whether they are designed to take 1 or 2 strings. If you can find data sheet for panels and inverter I can check figures for you