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plonkster last won the day on February 15

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About plonkster

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  1. Mecer 5kVa settings and monitoring

    I agree with Silver. You want at least a fuse in the DC line. Sometimes the inverter might have one. The fuse inside the inverter is actually there for reverse polarity protection. Diodes lose too much power and they get hot. So what they do is stick a FET across it that conducts if you hook it up in reverse and blows the fuse. But I still prefer an extra fuse, preferably on the battery side, because if I screw up somewhere downstream from that (who owns a proper insulated spanner and who just uses the 13mm from the main Gedore set?) I don't melt cables. Regarding earthing. Well, the case of the inverter itself should be grounded for obvious reasons. Now I don't know the Voltronics, how they do it. On the inverters I know, there is a bonding relay that bonds the neutral of the inverter output to the case of the inverter, so as long as the case is earthed, you get a full safe bonded setup. The early Voltronics didn't have the ability to bond earth and neutral. Later ones can. I don't know how it works, but it is important to get this right. You want earth and neutral bonded when it's disconnected from the grid and the inverter is running. You want the bond to go away while it's in passthru. We have this discussion at least once a month. Well I do... :-)
  2. Voltronic, Axpert, Gride Tie, Red Tape

    Newer models/firmware closes a bonding relay when the inverter is running. I bet you can use that.
  3. Water harvesting and use, same logic as solar systems.

    Again, I am so tired at people quoting this "we knew" story. Yes, we did, and we still do. The question is WHAT it was that we knew. We knew that on average, rainfall would come down. That was the prediction, and that is still the prediction. This year however, the last three in fact, is completely OFF the average, they are outliers. We didn't know that in 2011. No model could predict that, that is precisely the trouble with stats: It cannot predict outliers. It can only tell you that they are outliers. If the past few years followed the model that we KNEW about, we'd be at significantly less stringent water restrictions. Instead it threw an outlier we didn't know about.
  4. New Infini Super

    I think this is where the Pylontechs are coming in. We're at the point where a good set of Trojans cost the same as a comparable (mostly) Pylontech rack.
  5. Which batteries should I buy (rhetorical question)

    I was led to believe that the BMS uses the same (CAN) protocol as the BYD battery, which is also used by LG-Resu, and also used by Pylontech. Though it seems there are tiny differences between them. But their website seems to suggest they are using ODB2 (aka SAE J1939). It probably does not matter. These things all work the same way, they stuff all the data end to end into 8-byte packets with either the 11-bit ID in front or the extended 29-bit one, and chuck it onto the can bus. All you have to do is read them, chop it up in the right spots, potentially swap for endianness, and you're done :-)
  6. Anyone use Solarus panels before?

    Agreed, but I'm willing to bet money on it that those people telling you that this is "4 times more efficient" was looking at the overall output, ie hot water (reverse-calculated at 1.16Wh/liter/Kelvin) plus the PV output. Then 4x is not that surprising. Looking at PV output only... even a 50% improvement sounds too good to be true.
  7. Grid tie without battery backup question

    You mean SunnyIsland. Let's get technical. I think what those SMA inverters do (most likely) is include really big capacitors that act like small batteries, so you have a kind of self-consumption setup: The PV panels charge the capacitors, and a small inverter draws from it. Control electronics shut things off really quickly if they go out of bounds. And the PV array has to be 4x oversized. So the question is if this recipe can be scaled to 7kw. I suspect it can... but at what cost? Might be cheaper to put in a small lithium bank then and do a proper self-consumption setup. Of which Victron remains the best... (also, could not resist :-) ).
  8. Grid tie without battery backup question

    You sound as muddled as I do :-) Just read the SMA link I posted. It is simple enough. The inverter only provides a portion of the power so that even if there is some cloud cover it can still drive smaller loads. If you attempt to draw more power than it can handle, it switches off. If the cloud cover is really heavy, it switches off. Easy as that. Subtext: Don't be a dumbass and try to run your house off this feature :-) But.... never ever seen an actual model with this feature. Even in the US... that feature costs extra money so it's rare.
  9. Grid tie without battery backup question

    The secure power feature, at least on the SMA, is meant for small loads. It's sized no more than 25% of the nominal capacity. It's for charging of phones, non critical things. I've never seen it on a South African model. It's on some of the US models, presumably for areas that get bad weather where the power might be off for a few days. Then you can at least run some essentials. This case with the Goodwe was the first time I ever heard of it happening with another brand. So what I am saying is that it is at least possible in principle, and before you assume that it is a mistake, check the documentation. It might be a feature :-)
  10. Anyone use Solarus panels before?

    We all know that solar water heaters are significantly more efficient than PV panels. So it sounds about right, if you combine a single panel, generate some electricity and absorb the heat into water, you'll make at least 3 times the energy.
  11. Grid tie without battery backup question

    Yes. @Chris Hobson called me the other day about that. He had a Goodwe powering loads even though the grid was down. Keep in mind though that the Goodwe has an input and an output, and this was on the output, so no feedback rules are being broken here. I am also aware that some SMA models have a secure power feature that can power some loads when the power is out. It's meant to power smaller loads.
  12. 5kva Axpert MKS model - faulty

    Oh yes! I think the mypower24/solarmd people have the ability to repair as well.
  13. Water harvesting and use, same logic as solar systems.

    Schmutzdecke. Got to love the German language.
  14. Victron BMV 702 - No Power?

    Sounds like it isn't getting power. There's a fuse in the red cable that goes from the battery positive to the shunt. Check that fuse. Also check the RJ-11 cable running from the shunt to the monitor itself. I don't know the pinout of the cable, otherwise the obvious check is to measure if there is voltage on the cable where it plugs into the back of the monitor. The system will continue to work because the shunt is just a low-value high-current resistor and that still works as intended.
  15. Water harvesting and use, same logic as solar systems.

    Rumour has it JZ has changed his middle name to Takata. (If you don't get the joke, you probably don't drive a Japanese car).