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Tacet

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  1. Yep, that is the concept I use at home (my personal install is a Victron Multiplus II - works extremely well). Most telco sites, though, has too little roof space to supply even close to the full load from solar. The loads are usually connected to the batteries via an LVD that is controlled by the rectifier. Under normal operation the LVD will be closed. The batteries themselves are a fair range: 2 V VRLA, 12 V VRLA, lithium...
  2. Some perspective - most operators are preparing for >15 kW loads for each mobile site when 5G comes. I've seen small 19", 5U rectifiers that can do more than 20 kW. I see pros and cons to mixing on the AC side or on the DC side. Mixing on the AC side: As you say, it may well be cheaper. Extra conversion step - extra losses and extra things that can break. A really nice pro - on a site with multiple small rectifiers, a single solar installation can benefit all the rectifiers as well as ancillary equipment such as aircons. I don't think you'll be able to kee
  3. That's certainly the easiest solution, but not very efficient. Instead of a single DC-DC conversion you now have DC-AC-DC. Also, inverters tend to be more expensive than charge controllers, so it makes the ROI a more dubious deal. I try to keep work and forum separate, but this question piqued my curiosity, which is why I brought it here. The industry is telecoms, so the main reason for operating at DC is to keep the equipment permanently on batteries. A rectifier will typically be used to supply either multiple DBs or equipment racks, so in most cases you won't pull 625 A to a si
  4. System sizes are scalable - I'm looking at systems from 2 kW to 30 kW. I'm not worried about wire sizes - it is easy enough to bring your PV down to the charge controller at e.g. 250 V, and to install your charge controller next to the rectifier. I don't think it is quite that easy. If you simply parallel them and the output voltages are not exactly the same, the load will draw from the highest output voltage. If that is rectifier, then the solar charge controller will idle. If the charge controller tries to keep its output e.g. 0.01 V higher than that of the rectifier, the load will
  5. A device that takes as input either 3-phase or single phase AC, and rectifies it to -48 V DC. On the DC side it will usually connect to both load and batteries, and the user will be able to set the float voltage as required by the batteries. The rectifier can do temperature compensation and is able to limit the charge current to the batteries.
  6. Hi all, I'd like to pick a few brains, to see what the possibilities are. The company I work for have a few DC rectifiers supplying -48 V to various battery banks and equipment. We're unlikely to go for solar as we don't really have enough roof space. However, I'm curious about the concept: how would you supplement an existing rectifier with solar? The rectifiers are reasonably good at what they do, so you'd want the rectifier to retain control over the float voltage, temperature compensation, charge current limiting, LVD control, etc. Simplest way: install hybrid AC/solar rectif
  7. Oh, the diagnosis is pretty easy. The key issue in that installation is the installer.
  8. Agreed. I'm not an installer, and for me my installation was mostly a fun DIY project. But my Victron installation looks neater, is certainly safer, and has been working for months now. It doesn't cost much homework to realize that you really do want a GX. As for battery compatibility - as long as the battery can put out 48 V there's no reason for it not to work. I'm using Narada lithiums that can't speak to Victron at all, and it works. The drawback of not having communication is that you have very dodgy SoC readings (Victron think that mine is at 85% when it is fully charge
  9. @Pietvis - sorry for the slow reply, I don't browse the forums that often. The NPFC should have a little pinhole with a reset button behind it. IIRC it is to the right of the RJ45 sockets. It is pretty simple - you press and hold the buttons for a few moments. The status lights will cycle, and then the battery will switch off. Pressing the button again will swith the battery on again. I've found mine to be pretty finicky when connected to a Victron 150/75 MPPT - if there's no solar/inverter input to the MPPT the batteries tends to see the MPPT as a short and go into protection m
  10. There doesn't really seem to be much in the line of standard DB sizes, especially when looking at older DBs. I eventually got frustrated with my old DB and replaced it with a Hager board from Livecopper. The electrician asked me roughly R1800 to install the new DB. He enlarged the hole in the wall, did the plastering and rewiring, but I supplied all components. His work wasn't the best ever (I ended up shaking plaster out of the circuit breakers), but I felt that it was pretty cheap.
  11. My father's is ticking along really nicely - I'm keeping the grid breaker on for those occasional inrushes and for when the oven, kettle and geyser are on simultaneously - but other than that they don't really use much from the grid. Mine took a bit longer - I'm not going to climb onto my double storey's roof, so had someone install the panels for me. They did that this Tuesday.
  12. In my opinion Lithium's most important advantage - lack of fault current. Not having to worry about whether the busbars are too close to each other is so convenient.
  13. My father and I are both installing Victron systems in PTA. His is functional, but needs quite a bit of tidying up, while mine will hopefully be connected in an almost tidy state. A few random pics. Decided to mount the charge controller to the battery cabinet - wanted to keep all the DC in there and minimize the number of devices on the wall.
  14. Indeed, there is nothing inherently "better" to 48 V than 24 V. 48 V has the advantage of thinner battery/MPPT cables and lower rated switchgear, but higher voltages mean more cells in series in the VRLA string, thus higher probability of eventual cell imbalances. If your system is already designed for 24 V you're not going to save on cable cost by switching to 48 V, so why bother? Mmm, is there any advantage in terms of inverter efficiency in having a higher DC voltage?
  15. They give an equalization charge voltage of 56.0 V-57.6 V, but not a bulk charge value. Have you asked your supplier for the manual? They should be able to provide it. Otherwise, I think Averge is bringing Leoch in; they might be willing to assist if your supplier can't.
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