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PierreJ

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  1. Just an update on this: Turns out it was a problematic cell in one of the batteries. Once the battery was exchanged the warnings went away and haven't come back. Thank you @Youda and @plonkster. Oddly the firmware of the newer battery is almost a year older than the older batteries, even though the new battery was manufactured in May 2020 and the older batteries in November 2019. They seem to be working together just fine though. For anyone considering buying Pylontech batteries, but worried about warranty and support issues: My experience has been very positive. I dealt directly wit
  2. Not yet. I'm going to give it a few more days, and if I'm still getting high voltage warnings after that I'm going to make up the cable and dig deeper. Thanks for making it available. Should I be worried about these high voltage warnings, or is it safe to ignore them? Presumably the BMS will shut the battery down before the cells get damaged, right?
  3. I thought so too, but after a couple of cycles down to the region of 60% and back up to 100% it started throwing the warnings again. Perhaps a recurring cell imbalance? I've been coaxing it for more than a week now, so if it was only an initial imbalance it should have been sorted by now. Judging by the rate at which the voltage drops from 52V when discharging, and the rate at which the voltage rises above 52V when charging it's very clear that the Pylontechs store a minuscule amount of energy above that range. Presumably that means that even the tiniest of imbalances will
  4. Referencing a very old post here, but in the Venus OS 2.60 beta the Pylontech charge voltage was raised to 52.4V (we've discussed this privately), and a new feature was added to allow the limiting of the grid export. Using the latter with a low export limit (e.g. 100W) causes the charge voltage to rise to 52.8V, and sometimes briefly 52.9V. I'm regularly seeing "high voltage" alarms from the BMS at 52.8V. If I disable feed-in or allow the Multi to feed in the full excess then the voltage drops back to 52.4V and everything is fine. Perhaps 52.8V is pushing the envelope a bit, or I could just ha
  5. I'm busy looking at SANS 10142-1: 2017, but I can't find this requirement anywhere. Do you perhaps recall under which section it is stated? Looking at my main DB I see multiple violations of this, and it has passed two CoCs that I know of. Is this a SANS 10142 requirement?
  6. I haven't actually. I have ordered 6mm^2 cable online (which is massive overkill for the 10A it will be carrying), but I've never held it in my hands. Perhaps once I see it I'll be reassured. I'm leaning towards not using conduit at all now. I'm slightly worried about rodents gnawing through the cables, but if I look around in my ceiling I see plenty of tasty AC cables that have been there for at least a decade that haven't been touched. Thanks for the advice.
  7. The exact wording in section 6.2.6 is: "Positive and negative cables shall be run alongside each other, to prevent the formation of induction loops;" If I put the two metal conduits next to each other, touching, will that pass muster? It just seems safest to me to put a physical barrier between the +ve and -ve cables.
  8. I've read through the draft document, and the rules seem kind of strange: In section 5.3.5.2 it states "Where conduit is used for DC cables, it shall be metal conduit." Then in section 6.2.6 it states "Where a system features longer DC cables (e.g. >50m), consideration shall be given to the use of screened / armoured cables, or to installing the cable in earthed, metal conduit / trunking." And again in section 6.2.8 there is the wording "Where a system features DC cables longer than 50m, the cables shall be installed in earthed metal conduit or using armoured cable." So
  9. Thanks. That seems a bit draconian, given that 220V AC in PVC is apparently just fine. My plan is to run two separate conduits, one with + cables and a separate one for the - cables for my four strings. All the + and - cables will be shorted together in the combiner box anyway (after the fuses/isolators), so this should be quite safe. There will be 4 strings, so 4 cables in each conduit, 10A @ 200V DC. My application has been approved by CoCT, but I haven't actually started installing - the lockdown has put a stop to that. The big question on my mind now is that if this draft standard bec
  10. Are you sure this is a regulation in South Africa? I spoke to my solar installer and according to him PVC conduit is acceptable inside the roofspace.
  11. I've noticed this on the specifications page for the Fronius Primo: Fronius Primo 5.0-1, Fronius Primo 6.0-1 and Fronius Primo 8.2-1 are not fully compliant with VDE AR N 4105. I'm not familiar with the German standards, but perhaps that's also why it also does not have NRS0970-2017 certification?
  12. Well, that just threw a spanner in the works. It makes perfect sense of course, but I was foolishly assuming the CoCT wouldn't look that far. I've already paid the deposit on the Multiplus and SmartSolar, and I was about to pay the deposit on the Fronius. Thanks for the warning - you've saved me some money. If we both survive this virus thing and we cross paths in the future, remind me to buy you a beer :).
  13. Surely that is only an issue if it is connected directly to the grid? In my case the Primo is on the output of the Multiplus, so CoCT should approve my application right? The Multiplus will limit the current to 15A and also prevent feed-in, so as far as I can see all their major concerns are covered.
  14. If you're able to shift your heavy loads to the sunshine hours (like I am) it would be slightly more efficient to have one Multiplus together with a Fronius AC coupled inverter on the output of the Multiplus. The total capital outlay would be about the same, but there's one less DC - DC conversion. I submitted my application to CoCT last week and I'm now waiting for approval. I went for a 5kVA Multiplus, SmartSolar battery charger on 8 x 400W panels, and a Fronius Primo on another set of 8 x 400W panels. During daytime the Fronius will carry most of the load while the SmartSolar charges t
  15. If the 3kVA multiplus trips while transferring 32A then the transformer on the street corner would see a 32A load change. If one inverter trips it would just be noise, but if all the inverters in the neighbourhood trip in unison (which is not inconceivable) it could be a significant event. I'm not defending it, just stating what I believe the rationale behind it is. According to an e-mail exchange I had with CoCT the same limit applies to a UPS system - you may not draw more than 15A to charge batteries: "Any inverter used as a UPS must adhere to SANS 62040 for UPS sys
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