BigDee Solar

Thanks - one site was installed in March of 2021. The other one, with similar issues, is from June 2021.

Hi, I have an installation (on one of my customers' sites) of 2 X Axpert 5NB (Mecer) inverters. They are connected to two strings (344Voc and 258Voc) and 6 X US3000 Pylontechs. From time to time (random) the inverters trip (milliseconds), and loses their settings. So, they would go from 230VAC to 220VAC, 50Hz to 60Hz, but most problematic, the battery settings go from USE to FLD and the voltage from 53.0V to 58.4V. The latter is obviously deadly to the battery BMSs, and we have fried two of them already. Mustek shrugs their shoulders, and also sent me 71.92 firmware "to try and address the issue". The inverters show no error codes, simply flashes and restarts immediately. Has anyone else found similar random trips on their systems?

Hi, I have been following this discussion for a long time. Now, I am also a "victim"... I have 3 Axpert 5NB PF1 (Mecer brand) inverters, which have been running fine for at least two years. They are connected to three strings of 397V, 397V and 270V panel configs. Last week, I added three more panels to the low string, which now runs at 390V. Since this upgrade (did not touch anything inside), I get error 72 whenever my batteries (12 X US3000 Pylon) gets to 100%SoC. I run ICC monitoring software, and you can see when the green solar line dips from around 10kW to load wattage, the one inverter (always #2) errors. At this time, my LED lights in the house also go crazy and you can see serious jitter on the output voltage of the inverter. I spoke to Mustek, who sent me new firmware (71.92) - which I will flash later. I am running 71.86 at the moment.

Hi, not sure if your issue was ever fixed? There was a problem with the firmware of the 3000C batteries. I had LONG meetings and fights with Pylontech directly. They fixed the firmware a month ago... You need to flash the batteries with V1.9 - all issues should be fixed then.

Hi Shadders, how did you download the info from the inverter? Dennis.

I think the US3000C batteries have some issues... I have a standalone system with two US3000Cs. They work fine during the day, but the BMS alarms when discharging. The draw is only around 400W at night. When discharged to 60%, the BMS alarms. I reported this to Segen, and was told they have many 3000Cs being returned. They now need to replace some internal card on the one...

Hi, Which Inverter do you select on the PI, as it does not have the GroWatt on the list?