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MPPT VE.Can 250/100 rev2 Output low

Hi All here is my setup:

2 x Quattro 48/15000/200

1 x SmartSolar MPPT VE.Can 250/100 rev2

1 x 6kw Solis

3 x 200a/10kwh Rosen power wall with inbuilt BMS

35 x 390w panels (15 connected to MPPT & 20 connected to Solis)


I am told my panels are in strings of 5 on two separate roofs eg 3 strings of 5 making 15 panels on MPPT. I am finding that the 15 panels to the MPPT is roughly 25% of the output of the 20 panels connected to the Solis inverter. I am getting no response from my installer.

1659528053999.png


Both roofs are similar pitch and facing same direction there is no shading on either. The MPPT is always at around 25% of the solis inverter. Which is lower than what i had expected with a 5 panel difference.

Can anyone here help me understand if this is correct or suggest what i should look at?


Update: The company who installed have informed me the original installer has left them and a new engineer came out on 15th September. He confirmed that what i was told previously was incorrect there are 2 strings (6 panels and 7 panels) connected to the MPPT. He tested both and saw that both output the same Voltage and current to the MPPT. Disconnecting 1 string had no impact on the power generation of the MPPT but he could see voltage on the string when testing it.

I am now being told that they need to confirm that the MPPT has enough trackers to handle 2 inputs. I checked the VRM as to the exact model of the MPPT:

1663748432134.png

I do not understand what is meant by trackers as this appears to be the largest MPPT Victron offers and has enough input ports for more strings to be connected than the 2 i have connected. This seems to confirm that I am generating 50% of the power due to 1 string not being used but the question remains how can this be fixed?

Thanks

MPPT Controllers
1659528053999.png (55.9 KiB)
1663748432134.png (15.8 KiB)
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2 Answers
alator avatar image
alator answered ·

Hi all,

so the answer to this was due to a poor quality install. The installer finally came out and checked the wiring and found that 10 of the 15 panels connected to the MPPT were not correctly wired. Once they fixed the wiring the output is on par with the Solis inverter.


thanks

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Alexandra avatar image
Alexandra answered ·

@Alator

The favourites for this usually are (besides not actually having the correct settings):-

1. BMS is limiting the charge (not sure it applies in your case) I assume it is not Can or otherwise connected to the system.

2. Limit by DVCC for system charging.

3. Charge controller is limited in its own settings i.e. 100A set to 50A

4. Controller is too hot due to installation placement.

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alator avatar image alator commented ·

Thank you for the information.

I can confirm it is not hot as it is out in the garage and today is cool. I checked the charge controller and it is set to 100A.

If i look at the DVCC setting via the Cerbo GX unit or remote console it shows DVCC is turned on with only SCS enabled. I do not know what that means though.

1659540081870.png The battery BMS shows as connected1659540275273.png1659540316749.png

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Alexandra avatar image Alexandra ♦ alator commented ·

So none of the usual culprits. Did you check the settings on the mppt itself?

The other way to check if the battery or the system is restricting it somehow is to unplug the connection to the gx. Reset it to stand alone with Victron Connect, set it up again and check it that way.

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alator avatar image alator Alexandra ♦ commented ·

I accessed the MPPT via Victron connect app.

today lots of sun can see solis is doing well but the MPPT isn't so much

1659613828772.png

I don't know enough to be disconnecting parts or setting up the system. This shows the solis and 20 panels outtput at maximum yet the MPPT not reaching 50% of it capable 4kw. Does this look like to you this is setup incorrectly?

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klim8skeptic avatar image klim8skeptic ♦ alator commented ·
You have a CCL of 150A, and the above VRM screenshot shows the battery being charged at 148.9A.


If your battery can handle it, nudge the CCL up a bit?

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alator avatar image alator klim8skeptic ♦ commented ·

Interesting i did not notice that. Though I cannot modify the BMS on the battery. I wonder if that would mean the MPPT could provide more power if I was drawing more power rather than charging the battery?


though I have my doubts when there is less sun and the Solis is not at max the output of the MPPT still seems much lower

1659616031003.png


The solis has 20 panels for max output of 7.5kw but itself can only manage 6kw so in this screenshot it is achieving about 20% of the max 6kw.

The MPPT has 15 panels for mx output of 5.8kw and the mppt can achieve 5.8kw max. I know that can't be reached as panels are never perfect so say 4kw max. So in the above the MPPT is achieving 8% of the max 4kw output.


With no shading shouldn't those two values be little more closely matched. Am i thinking about this wrong?

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klim8skeptic avatar image klim8skeptic ♦ alator commented ·

With no shading shouldn't those two values be little more closely matched. Am i thinking about this wrong?

I would expect the figures to be "proportionally" similar. Victron 15:20 Solis.

Your initial post 25% mppt figure would seem to be reinforced...

Post the specs of your panels, and a midday PV voltages/currents from both pv arrays.

What is the CCL of your ROSEN battery?

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alator avatar image alator klim8skeptic ♦ commented ·

The two screen shots posted above today were from around midday today. The post above that with the CCL (150a) i think is the CCL of the battery. I do not know enough to look elsewhere and cannot get details from ROSEN. I am still trying to get the documentation from the installer for all this.

This is the information i was provided for the panel at the time of quotation and told i was getting the 390 panels.

Q.PEAK DUO ML G9 370-390.pdf

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