Hi all, good to be here! I've just installed this inverter, I have 12 400W panels connected 6 series into the two MPPT inputs.

I have priority set to SUB, (largely as my battery, a Meterboost 2.4kWh isn't really big enough) but even in full sun the inverter stays in 'bypass' mode, and although also showing a path from Solar to the load, its drawing a negligible amount from the panels.

Am I missing something here, a setting somewhere I haven't found? 

My previous inverter was a Kodak 5000 which has the same control box, but that one worked ok.

It's most annoying!

Help appreciated.

 

Andy

Spain.

Can you check your panel voltage? If it's around 90 VDC, then it's a known bug.

The panels are delivering around 250V in full sun.

 

 

20 hours ago, AndyLinton said:

The panels are delivering around 250V in full sun.

Is that when they are drawing their negligible power from the panels?

But even if 4.8 kW of panels were dragged down from 250 V to 90 V, I would expect much more than "negligible" power from them. In winter, I'd expect something like 4.8 x 0.75 * 0.9 * (90/250) ≅ 1.2 kW. The 0.75 is for winter real-world conditions, and the 0.9 for the current being dragged away from the Imp. 90/250 obviously for the voltage change.

So it doesn't sound like that particular bug.

On 2022/06/12 at 10:24 AM, Coulomb said:

Can you check your panel voltage? If it's around 90 VDC, then it's a known bug.

I also have a axpert max 7200 that in a seemingly random way switch to bypass and is stuck there unless a full reboot, without a utility connected.

So, I am really curious on what is the "known bug" and the possible "better solution" than mine

Thank for your help

 

7 hours ago, Damiano said:

So, I am really curious on what is the "known bug"

I don't fully understand it. Somehow, the MPPT (which is really a "hill climber" rather than a true Maximum Power Point Tracker) gets stuck in a mode where it pulls the panels down to the lowest MPPT voltage, which is 90 V. It seems to stay there until the PV current increases to at least 0.5 A, by which time you could be losing a lot of potential solar energy.

There were plenty of bugs in early Max firmware, so it's worth updating to the latest firmware, which I believe is 90.19, but the MPPT 90V issue is still there. Fortunately, fellow forum reader @Georg594 has worked out a series of patches with his 8 kW firmware, and has kindly ported it to 7.2 kW firmware version 90.19 here:

The post says it's still untested. Perhaps you'd like to be the first tester? 7.2 and 8.0 kW firmware is quite similar, so I'd say that the risk is quite low.

 

Hello, thanks for your reply

My reseller gave me the MCU fw 12.21 that I successfully installed using the serial port

I think you are quoting the DSP firmware, that should be

>> bytearray(b'QVFWb\x99\r')
<< b'(VERFW:00045.07\x05)\r'

I can surely test a new FW but I need a way back in case something goes wrong

Possible ?

11 hours ago, Damiano said:

I can surely test a new FW but I need a way back in case something goes wrong

Unfortunately, there is no "undo" of firmware updates. Fortunately, there is an "overwrite", just over-write with factory firmware. The latest for your model is version 90.19:

I happen to have your exact 45.07 firmware as well (it's a fair bit older than the above), for maximum safety.