Not seeing any current when connection panels in parallel.

[dajale]

Hi All,

I have 6 x 200W solar panels. I have tested two banks of 3 panels linked in series independently. Both of the banks show current flowing on my Growatt 3000W system.
I connect all 6 of the panels in series and I see current on my Growatt.
I connected both of the banks of 3 panels in parallel and see no current. Based on how the panels are created there does not seem to be a way to mess up the wiring. Does anyone have any ideas of what might be wrong?

Thank you,

p.s. this is a great message board everyone is very supportive and forthcoming. I have been very excited about getting this solar project off the ground. Thanks for your help

Dajale

 

[sunshine_eggo]

Given:

6 total panels.
6S array works.
3S array #1 works by itself.
3S array #2 works by itself.
3S2P array (#1 and #2 wired in parallel) does not work.

I would conclude that one or both of the connectors you're using to parallel the strings is bad.

 

[12VoltInstalls]

Based on how the panels are created there does not seem to be a way to mess up the wiring

These MC4 connectors I’m assuming
So we can assume you are correct.

one or both of the connectors you're using to parallel the strings is bad.

That is the most obvious conclusion. Do you have a second branch connector to try? If not, order them ASAP.

FWIW I’d buy either the same brand as the panels - or, the only consistent ones I’ve found (having had problems similar) is Bouge RV.

Q: Is the cable to the charge controller the same brand w/ premade ends as the panels? Or did you crimp yourself?

Even though an MC4 should be the same from ANY supplier I’ve decided they are not. I don’t know if Bouge RV is the best (probably not) but they’re inexpensive and I’ve changed out most of mine to Bouge cuz they work. Generic or weird name Chinese ones do not always make a good connection, break, or leak water when attached to WindyNation, Rich, or Bouge MC4s is what I’ve found. IP66 shouldn’t leak water but the cheap MC4 ones: do.

 

[pollenface]

I tend to cut connectors off, splice, solder and heatshrink for not having to worry about bad connections. It makes it more trouble when reconfiguring arrays but I don't reconfigure them too often.

I passionately hate MC4 connectors.

 

[robby]

I would first check the Voc of the 3S2P array and see what the voltage is. Then check the voltage again when connected. It’s most likely a bad connector but that 5 minute check can confirm it. What’s the starting voltage for your inverter? 3S seems real low.

 

[12VoltInstalls]

Hopefully this was solved Nov 10th or before. Last here Nov 29th with no update from OP