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Coulomb last won the day on July 14

Coulomb had the most liked content!


About Coulomb

  • Rank
    Advanced Member
  • Birthday 05/11/1958

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

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  1. I count four adjustments per year, one for each season. But I wonder at the usefulness of this. Why not leave it at the winter setting? The mismatch of pitch in the other seasons is partly offset by longer days. Of course, if you need to run air conditioning in summer, that could make it worth two adjustments per year.
  2. Coulomb

    How to find axpet vmii fiermwaer plz help me

    It's in the files section of this forum: I see that there is also the firmware for a VMIII model. They almost certainly use the same reflash tool, so if you have trouble opening the .rar file (I use 7-zip, a free download, just Google it), you can open the .zip file for the VMIII by double clicking on it, and use the UPSReflashTool.exe from that zip file.
  3. Coulomb

    Axpert VM III

    I've often wondered about that. Yes, there is no transfer time, but there may be a very similar effect. When the grid goes down, depending on where the disconnection happens, there could be a hundred houses of load at the AC input connection. So the AC input, which is initially still connected to the AC output, is close to a short circuit. So the output will go to zero volts until the inverter can disconnect the AC input. Disconnecting a relay might be a little faster than connecting, but it will still be of the order of 10 ms, I would think. But now, different to the non-hybrid setup, the inverter is working into a short circuit for that time, and the input relay opens under that overload situation. That has to be hard on those components. Meanwhile the load sees a similar drop in voltage. Have I got that wrong?
  4. Coulomb

    Patched firmware based on version 73.00

    That's not a bug, that's a feature! You''re supposed to look at it like this: The "MS" stands for MaSter. As far as we can tell, "HS" is their attempt at making two seven-segment characters look like "MS", using their rather poor "font". It's impossible to please everyone, but the changes are all meant to be improvements. They should all be mentioned in the AussieView™ manual. If after reading the manual you think that something is unreadable or missing etc, please post specifics. In particular, the keys don't work the same in information display mode. All I can think of is that perhaps some monitoring software is running in the background (e.g. you might have tried WatchPower and thought that closing the window would stop it from running. You need to use the system tray to exit, as explained in the middle of this post (NOTE: the software in that post is not the latest).
  5. Coulomb

    Axperts in parallel

    I think that this is a good idea. I believe that in Australia, it is mandatory.
  6. Coulomb

    Summer > Winter power generation

    It would be good to know how much you reduce that 50% winter penalty by at 45° tilt, compared with 27°.
  7. Coulomb

    Axpert "back to grid" behaviour

    Looking more through the code, either the behaviour has changed, or I mis-remembered. The main way for the load relay to be off is if you are in standby mode (the inverter switch is off), and you'll always see setting 28 (at least in 73.XX factory and patched firmwares). It silently refuses to change setting 28 if the output relay is on.
  8. Coulomb

    Axpert "back to grid" behaviour

    Correct. The Parallel Manual states: "*This setting is only available when the inverter is in standby mode (Switch off)." But my recollection is that if the inverter is switched on, you don't see setting 28 at all; it would go from 27 to 29 without stopping at 28. [ Edit: but see next post. ] That's presumably not the same as trying to set it to Sig and having it fail to "stick", or no having the Sig option (only PaL and the three-phase options). I'm surprised by not being able to change setting 28 to Sig with a parallel card installed. But as @ebrsa mentioned, I don't have a parallel system myself, so I can't speak from personal experience. Looking at the code, it seems that if the load relay is on, then you won't be able to change the output mode. That makes some sense, I suppose.
  9. Coulomb

    Summer > Winter power generation

    What tilt are your panels? I think that at least some panels should have a pretty large tilt, say 45° (for latitude 27.5°, Brisbane Australia), so production is better in Winter and worse in Summer. That would balance to some extent the longer days in summer. But it's far more convenient to have panels flat against roofs. Here, the roofs are often at less than 25° tilt. What's it like in various parts of SA? I imagine you don't need steep roofs to stop the snow from building up, same as in 99% of Australia.
  10. Coulomb

    MECER AXPERT SOL-I-AX-5M Settings Help

    Ah. My mistake.
  11. Coulomb

    MECER AXPERT SOL-I-AX-5M Settings Help

    No, that's 87% of nominal. I get about 75%, Pilotfish's 4.4 / 6.2 is 71%. I think that's fine. [ Edit: I was assuming 12 panels total, which is wrong.] As mentioned already, it could well be the main charge bug that afflicts all parallelable Axperts (whether paralleled or not). Our patched firmware should fix it, and charge your battery properly. I hope they are not too damaged through under-charging. [ Edit: the charge bug won't affect peak power (kW), but will affect total energy into the battery (kWh) by bulk/absrb charging too short.]
  12. Coulomb

    midpoint panic

    Indeed, Plonkster. I often have difficulty forcing battery or bypass modes when I want to, but I'm too lazy to set up the Node-RED buttons to make it easier. I rarely need to do it, so the pressure to do it never builds. Basically, to get from bypass/line mode to battery mode, you have to change the priorities of source and charging, then wait for the battery voltage to exceed the Back To Discharge setting (setting 13) before the change actually happens. Maybe ICC changes all three settings to make this happen, then sets setting 13 back to what it was, I don't know. There is also a 10 minute minimum time before it switches (2 minutes with patched firmware), though there seems to be exceptions to this minimum that I haven't bothered to nail down as yet.
  13. Coulomb

    midpoint panic

    Yes, they conflate the terms "bulk" and "absorb", often confusing the reader by using the wrong term. You can set the float and absorb settings temporarily to be the same if you want, just don't have float higher than absorb. The diagram at the top of this forum page that you pasted from the Axpert manual is a bit of a copy and paste error; it's for another product entirely. Crisp correctness in the manuals is sadly not a priority. So for example where it says in small print that the absorb time (T1) is 10x the bulk time (T0), that simply doesn't apply to Axperts.
  14. If the MPPT is blown up, and the seller won't replace it for a reasonable fee, then you may be able to purchase just the MPPT board and replace it yourself, or get the inverter repaired (so they replace the MPPT board for you and you still have warranty). The inverter part, which is the majority of the cost, should still be fine. But you way want to trade up anyway as Pilotfish has suggested. If the MPPT has died, the symptom would be that you won't see the PV panel icon appear on the LC Display, and you won't have a U2 firmware version number, even with correct-voltage PV connected. The inverter part (which drives the display) can't tell the difference between no PV input (e.g. night, not connected yet) and a completely blown up MPPT. So you won't see an error code related to a faulty MPPT / Solar Charge Controller (SCC). I'm speaking from 5kVA model experience here, but I believe that the smaller models behave much the same.
  15. Coulomb

    Lights Flickering when on Battery Mode Axpert

    I'm surprised that others haven't offered an opinion. 15 VAC is about 6.5% of 230 V. A lot of electronics these days have what's called a Power Factor Correction (PFC) stage. This is a poor name, really it's just a circuit to make the device look more like a resistor than a diode and capacitor. These will struggle a little to follow the mains voltage jumping about, hence the flickering LED lights, but won't be stressed at all. Old-school devices that are a bridge rectifier followed by a large capacitor and no boost stage don't care about the mains voltage going down, but when it comes up, they'll have a bit of a surge in current. This will cause a slight hit on their life. But as others have pointed out, Eskom mains voltage can fluctuate pretty wildly anyway, so I don't think it's serious. Things like toasters, ovens, incandescent lights, and motors won't care at all, at least in terms of life. I wonder if smaller motors might have a slight hiccup. A stiffer battery and thicker cables can minimise the effect.