sp22

A quick update, now thats interrestings, ive just disconnected battery with inverter still on and working and with no batt connected it reads 55V, but when ive connect the battery the reading is correct... and its not from charged caps, the voltage on terminals is stable, also loading with 2.2k load did not changed it. It also does not report BP wich is logical if it sees there some voltage but from where it is leaking there.

Hi, all tests were done on a discharged battery to about 1/4 capacity (also i have almost constant load of 2.2kW on the inverter(heat pumps), interresting thing that ive noticed, that if i swapped the MPPT board and also the CPU for some short time (mins) it was OK, than it dropped to 1.4 and stayed there. There must be something wrong on the main board, but what. Bat voltage reading is off by about 300mV at 60A load current. As i sayed if i change the whole inverter to friends VMII, but all setings are the same ive getting instantly more than 2.5kW from the arrays. (the arrays are 3.8kWp in total) and the borrowed inverter seems to use all available power. (We have here now a lot of sun). It looks like somehow the drawn power from panels is power limited to 1.4. But what could possibly cause it?

Hi friends, after some 3-4years my VMII 5.5kW began to develop a strange problem. On solar input it loads panels only to 1.4kW and then stops, i have checked on another inverter with same settings, that the array produces 3.6kW. Had someone this kind of problem? Other functions of inverter are working. Can someone help me?

Hi friends, im repairing my MAX 7.2. It had AC/DC IGBTs blown, i replaced them, checked optocouplers, and driving circuitry it looks ok. I also checked the UC3845 wich works(Generates about 95kHz). But it still gives F09 and the fans keep working at max speed. Can someone help me? If im correct, the softstart board should be on top of the MPPT PCB. Am i right? If yes is here some reversed schematic? I also checked semiconductors on the softstart board but everything looks ok. Also on main PCB all transistors and diodes are checkd. Is the maximum fan speed dependend on the F09 error, or is the CPU thinking of some NTC overtemp failure and so it does not enable drivers?

Thanks for your reply. I have one spare inverter board wich i could sacrifice for this purpose. I dont know if the eeprom is externally readable, if yes i will back it up and try luck with the utilities. If i find something on internet.

The inverters are running separately. It seems that these clone units have copied firmware also with serial numbers. (Is the SN part of firmware flash region?)

Hi friends, i want to ask if there is any tool, to patch or edit serial number of this inverters, as i have 3 of them but all of them are sending the same generic serial wich has 3535 pattern in it xxxx3535xxxx....? On the stickers the SNs are not identical. I am making a small ESP32 based reader wich reads data from up to 6inverters and send there to emoncms (i use serial as the NodeID) but this is impossible to implement when 3 inverters are sending the same SN.