Overvoltage issue

[SirHund]

So I searched around a bit and didn't see anything that got this topic. While I'm sure I missed it I need help. I was running 4 renogy 100w 12v panels parallel but recently went 24v series with them. Immediately had issues, had way too big of a battery bank to keep a good charge and just drained the batteries. Fixed that issue and just removed batteries until I could get more panels.
well I found some cheapo panels at the scrap yard so I grabbed them. Photo something or other brand. 50w each. Got 4 of them. Wired all of these in series with my renogy panels and all the sudden I have an overvoltage code (E10) on my rover 40a controller.
check the voltage and yeah sure enough it was running 152.6 volts. Controller is rated for 100 v max. But at 1100 watts total on the controller in series 24volt
where am I going wrong if I only have 8 panels totalling 600 watts?
is it the simple fact I have 8 panels? Need help. This is my only power source.

[littleharbor]

Photowatt had a series of panels that could be configured for 12 or 24 volts. although if you have all 8 in series from reported voltage sounds correct. If you series wire 50 watt and 100 watt panels you effectively have created an entire array of 50 watt panels. You would need to series wire the 50s and 100 watt

panels separately, then parallel wire the two strings.

Photowatt 105 2.JPG

[SirHund]

littleharbor thank you for the fast reply. And I don't understand how I created an array of 50w. Not am I going to argue it. I will trust you on that point.
But if I'm understanding you... I need to wire up each set in their own series. The parallel the two series sets down to the controller and this will cure my issue. As long as that is all that's up.
And yes that pic is the exact panel I found except mine are 50watts each. All tested out super strong an got them for 120 bucks so I figured it was an ok deal.

[littleharbor]

The problem when series wiring dissimilar panels is that The current of the lower output panels will dictate the current of the string. If your 100 watt panels are 6 amps and the 50 watt panels are 3 amps, when you put all 8 panels in series your string will put out 3 amps a whatever the voltage adds up to.
If your 50 watt panels are configured for 24 volts they need to be reconfigured for 12.

And, yes, creating two strings will cure your high voltage issues. Photowatt wiring jpeg.jpg

[SirHund]

We almost got this done last night and the rain hit us. I missed your diagram but got out there this morning and just finished up all my tests. Had to remove all panels and reposition them due to wiring lengths.

However......It worked like a charm! Thank you very much for your FAST assistance and helping me with this. I have been on a 6 month long offgrid journey and all was well while on 12volt because it is basically plug and play. Jumping to 24 isn't so much more involved that it's difficult or anything but I did notice a learning curve. It has been fun and I don't plan to stop.

Again thank you and thank you for this forum! Absolutely amazing! Glad I found this place! Hope to meet many more nice people on here and one day be called a Vey of Solar.

Have a bright and shinny day people!

[SirHund]

Oh and I should add that on your diagram assuming it is.of the original charge controller attached to the Photowatt panels....i removed all of them and put them in the "use later maybe drawer" along with my PWM. I used some extra mc4 cables I had laying around for a project to hard wire into the junction boxes on the back of each panel. Actually went quite smooth compares to what it could have been.

[littleharbor]

That diagram is showing the J-box on the back of the panels. For 12 volt wiring you use two 12 gauge jumper wires, one from position 0 to position 4 and another from position 2 to position 6. For 24 volt you need a single jumper from position 2 to position 4. The Charge controller is entirely a different component.

[SirHund]

Ohhh ok well that is good to know. All my panels are 12volt but now I'm curious if my Renogy panels are built the same. Because if that's the case I could honestly go through and rewire every thing 24 and series them into 48 in theory I suppose. At least when that time comes. But again thank you. My batteries are about to hit boost on my controller and I love that sight lol

[Mikenreurs]

"For 24 volt you need a single jumper from position 2 to position 4. The Charge controller is entirely a different component."

Thanks for the tip, man! That's definitely helpful.