Hi all, this forum should come with a warning label 🙈 I spend WAY to much time on here. Have learned a lot in the brief time I've been a user (or at least I think I have). On to my question.. I have an array of 15 Canadian Solar panels (405W), well technically only 12 as the other 3 are on a separate array connected to a PowerOptimal Elon for heating my geyser. I'm trying my hand at reverse calculating the array's wiring configuration based on amperage. I've been observing it over the last couple of days, and it rarely rises above the 20A mark (earlier today it briefly breached 30A, but only for a few seconds).

Would it be accurate to assume that, based on this maximum amperage observation, my array is likely wired completely in series? My panels are roof-mounted, north-facing with zero shading/obstruction so this would be feasible. Just checking my logic...or in all likelihood, the lack thereof 😏

if you are getting 30A, there is a high possibility that they are wired 4S3P 

Edited December 16, 20213 yr by hoohloc

Not knowing your panel specs, I'd say you have 3 strings of 4 panels in series.

Just now, 0012 said:

Not knowing your panel specs, I'd say you have 3 strings of 4 panels in series.

4 panels connected in series, then 3 of those 4 series connected panels are connected in parallel 

If your solar voltage was 150V when you saw 30A briefly, that's 4500W

12 panels x 405W = 4860W so that would be close to the max you'll get out of them.

 

And if you get 10A per panel string at max current, that points to 3 strings.

 

So my guess is 3 strings of 4 panels

1 minute ago, 0012 said:

If your solar voltage was 150V when you saw 30A briefly, that's 4500W

12 panels x 405W = 4860W so that would be close to the max you'll get out of them.

 

And if you get 10A per panel string at max current, that points to 3 strings.

 

So my guess is 3 strings of 4 panels

Or  4Series 3Parallel 

Thanks for your thoughts @0012 and @hoohloc – a 4S3P configuration would make sense (the optimal operating voltage for my panels is 41V, so with four in series, that doesn't sound far off). You were correct @0012, my panels are rated for 9.65A per panel string, so that checks out too

So much to learn, but what a resource this is! Thanks again

Just check your graph for amps and voltage.