600 watt 3s2p not producing

jamackw

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Sep 1, 2021
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I have 4 new 100watt panels and 1old 100 watt panel made by rich and a 100w go power wired in 3s2p to a renogy rover 40a mppt. I am not getting the amperage into or out of the mppt. It shows up tp 67 volts .5amps. 12 v 2.5 amps out of scc. I need some help please
 

chrisski

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Can you tell us specifically how your 3S2P is set up?

What are the VOC and VMP of the 4 new panels, and also of the two other?

One thing I can think of is one of those panels puts out way more voltage than the others and you have a mismatched string of three.
 

jamackw

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Sep 1, 2021
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The new ones are higher than the old one by .3v if I remember correctly new ones are 22.1voc and 5.49 imp 18.2v vmp. I'm getting the correct voltage out of them just not the amperage
 

jamackw

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The new ones are higher than the old one by .3v if I remember correctly new ones are 22.1voc and 5.49 imp 18.2v vmp. I'm getting the correct voltage out of them just not the amperage
The old one and the go power are on a string with a new panel
 

Bud Martin

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Can you show us the pictures of your setup?
Did the setup ever work before?
 

chrisski

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The new ones are higher than the old one by .3v i
Panels are nearly perfectly matched, so this is not a panel mismatch problem.

The more info you give us on your system, the less mis-guessing on my part.

What is the SCC Settings for float, absorb, and equalize? 12 volts charging is really low. It should Absorb at 14+ VDC, and float above 13. At 12 volts, not surprising only 2.5 amps go into the battery. These settings should closely match what is on your battery spec sheet.

If you have a way of measuring short circuit amps of one string at a time in full sunshine, you should get pretty close to 5 amps. If you can measure two strings at a time, just watch the amp meter. Most meters I’ve seen that use leads have a fuse that blows at 10 amps, and your two rows of panels will exceed that. A clamp meter may work better.

I troubleshot my 3S2P set up yesterday. Had a dead string. I had two problems. First was the combiner box had a screw that came loose so killed the connection. The second was a pin was pushed in on one of my connectors. This caused a whole series of three panels to not provide power. After I fixed both those problems, the system worked good.
 

jamackw

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Here's the solar
Panels are nearly perfectly matched, so this is not a panel mismatch problem.

The more info you give us on your system, the less mis-guessing on my part.

What is the SCC Settings for float, absorb, and equalize? 12 volts charging is really low. It should Absorb at 14+ VDC, and float above 13. At 12 volts, not surprising only 2.5 amps go into the battery. These settings should closely match what is on your battery spec sheet.

If you have a way of measuring short circuit amps of one string at a time in full sunshine, you should get pretty close to 5 amps. If you can measure two strings at a time, just watch the amp meter. Most meters I’ve seen that use leads have a fuse that blows at 10 amps, and your two rows of panels will exceed that. A clamp meter may work better.

I troubleshot my 3S2P set up yesterday. Had a dead string. I had two problems. First was the combiner box had a screw that came loose so killed the connection. The second was a pin was pushed in on one of my connectors. This caused a whole series of three panels to not provide power. After I fixed both those problems, the system worked good.
I've got a 12v 3kw aims invertercharger and 2 sok 206ah batteries. And the rover scc in a tt.
 

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chrisski

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I really think the leaves on the panels are enough To do reduce the power. My next step would be to sweep the leaves off and try again.

There’s some pics in this thread that explain how little shade it takes. It shows a pic of my hand shading two cells in a single panel on my series of three and it reduced output by 25%. Shading half of one panel in the series of 3 reduced output to 75%There’s enough leaves across there, could be an issue.

 

chrisski

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Not sure if this will help, but I put this together yesterday after fixing my combiner and connector in my 3S2P problem. This covers how to find problems with panels and cables, but nothing after it touches the SCC. Won't cover troubleshooting the SCC or problems from there to the battery.
 

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