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Coulomb

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Coulomb last won the day on February 22

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About Coulomb

  • Birthday November 5

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    Male
  • Location
    Brisbane, Australia
  • Interests
    Solar energy systems with storage; firmware for inverters and chargers

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  1. Boy, didn't you cause me a lot of work with that post. But thanks for the valuable pointer!
  2. What you could possibly do is build an "active zener". That is a small circuit driving an IGBT in linear mode (I can't recall if that's advisable, I know you can do it at lower voltages with a MOSFET). It probably has to be many IGBTs in parallel with separate gate drivers. These would have to be on an absolutely massive heatsink. High DC voltage hazard, lots of protection needed. Nothing simple, inexpensive, or easy there.
  3. Circuit breakers operate on current (and a little on temperature), not voltage. The voltage rating of a breaker is the maximum voltage that it is guaranteed to safely disconnect. Exceeding the rated voltage makes it less able to electrically disconnect if you were to mechanically set it to "off", not to have it automatically disconnect.
  4. That high when the BMS issues this status... my wild guess is overshoots from the solar or utility charger, probably when largish loads come off. I'm out of ideas, unless letting something like Solar Assistant coming between the inverter and the BMS somehow helps.
  5. Oh, that's warning code 60 (⚠ means warning). I was not expecting the inverter to stop output on a warning. Now I suspect that your problem is with the battery; it should not be telling the inverter that it can't discharge (or charge) the battery. Presumably, that would cause the inverter to drop its output, since it's not allowed to discharge the battery. What is the state of charge of the battery when this warning code occurs?
  6. I've not tried it, but from reading various firmwares I'm 99% sure that it won't work. But I see no reason why the inputs to the on-board chargers can't be the same phase (0° phase shift between the active conductors). So you could connect L1 on the wall connector to one inverter, L2 to another, and leave L3 disconnected. The on-board chargers are connected wye, not delta, so I believe that this would work. Or if you want to leave the two inverters paralleled, connect both L1 and L2 to the single phase output, and again leave L3 disconnected. This would give you 14.4 kW charging. If you have no other loads at all, you could connect L3 to the single phase paralleled output as well, and that should give you 22 kW charging, assuming that you have enough power source(s) to drive the inverters. That would be well over 450 A at 48 V, to charge the EV from the inverter's battery. You really need to know what you are doing at this power level. Few EVs can use 22 kW of AC.
  7. Fault code 60 (Current feedback into the inverter is detected) is supposed to be a parallel function. You say you have a single inverter. Do you perhaps have setting 28 (output mode) set to PAL for Parallel? Strangely, some inverters seem to be delivered in this configuration. Sadly, I've not had the pleasure.
  8. The latest 81.xx that I have is 81.07. You could update them all to that. I have a vague feeling that it won't fix the problem, but I can't recall why, sorry. I can't recall where I found this; use at your own risk. MAXII_8K_81.07.rar
  9. I don't believe that this is true. How would it cut the input? I believe that there are 500 V rated capacitors directly across the PV input. These won't fail immediately if they see more than their rated volage, but will fail much more quickly than they should. But as per below, I suspect that this is not your problem. Apologies for my stating that your model has a 450 V PV voltage limit; I must have been looking at an older model's manual, or the MKS IV when you have a VM IV. This, coupled with cold temperature (panels less than 25°C) is the combination where the PV voltage is highest. With no load and a full battery, there is nowhere for the solar power to go, so the inverter does not load the panels at all. So we see Voc from the panels. Obviously, strong sunlight (at least initially) leads to the highest panel panel voltage. Eventually, the sun will heat the panels and that will decrease the voltage, but if an over-voltage has happened, then it's too late. My guess is that your inverter is reading a higher voltage now than actually exists. Can you carefully check the PV input voltage with a multimeter, and compare it with what the LC Display or monitoring software says? A moderately common failure is for voltage sensing resistors to go low in resistance compared to their nominal value, due to moisture and/or dust creating a path around the resistor, where the conformal coating has worn away or was imperfectly applied or cracked. When the resistors have lower electrical resistance, the inverter reads the voltage as higher than it really is. So I'm guessing that now it's reading above the limits, whereas earlier it was reading correctly, or a little higher but not yet over the limit.
  10. Sorry. Not owning one, this is beyond my capability, at least at this stage. I have no idea. My Axpert MKSs from 2015 are so very different to these.
  11. The limit for your model is 450 V. It likely won't generate any power over 430 V. The difference since April is possibly due to panel temperature, although I expect the highest panel voltage at the lowest temperature.
  12. There are two in the thread linked below. There is also a display firmware, although the 38.xx display firmwares confuse me.
  13. I would say it's just OK. Voltage regulators usually have a 5% tolerance; 95% x 12 V = 11.4 V. But if there is significant ripple on the output, then it's no good. For example, if the 11.5 V is basically a sawtooth from -12 V to -11 V, then the electrolytic is bad, or maybe 1 A of load is too much.
  14. Alas, my notes say that a firmware has to respond to a QDOP command for this to work, and 74.04 does not appear to support that command. Maybe that means that there are different 74.04 firmwares; it would not be the first time. But also, I don't recall how I decided that the QDOP command was involved; I might be wrong there. I don't have display firmware version 30.07 to check, either.
  15. So this is a U5648MS? (Also known as an Axpert MKS 4 5.6 kW). As far as I know, 74.04 is a '2809 firmware, and the reflash tool appears to be old-style with no way to enter a hex file name (used the fixed name dsp.hex in the same folder as the executable). So I'm puzzled why in your screen capture, the word "28066" appears in the title bar of the application's window. Maybe they supplied the wrong reflash tool? You may care to diff the 74.04 dsp.hex in your firmware update file with the one here: You might also care to try that firmware update file's reflash tool. To tell what DSP you have, usually you use the main firmware to decide, and I have firmwares 74.02, 74.03, and 74.04, all of which I've labelled as '2809. If you are prepared to open your case, you can tell the DSP (at least '2809 versus '28066) using the Chipset Chatter post. If you post a link or attachment to your firmware update file, or PM me a link or attachment, I can compare them here, and/or determine whether the firmware is for a '2809 or a '28066.
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