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P1000

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Everything posted by P1000

  1. But that's a grid-tied, so no battery. They also cannot do unbalanced output, so not ideal for residential.
  2. I'd go for 2x12kW over 3x8kW because you have redundancy, and you have 12kW per phase, where with the 3x8 you only have 8kW per phase. I can't find specs on the 24kW unit you refer to, do you have a link?
  3. Why would the relay fail? It is switching no load, unless something has gone terribly wrong. From a random hager contactor datasheet (using a contactor as worst case, relays have 10x the mechanical operations): Since their is no electrical load, we use the mechanical endurance. Say you get load-shed 5 times a day: 100000/5 = 20000 days = 54.79 years If you take the 30000 number you get 16.44 years.
  4. Not necessarily, for example, the DEHNGuard basic above, has a gas arrestor in series with an MOV to reduce leakage. Also, the indicator is supposed to turn red before the MOV fails, which also shorts the input to ground mechanically, tripping the upstream breaker.
  5. Sounds like the manufacturer rejected the warranty due to fault of the installer, and he "found" a different reason to give to the client.
  6. I'm pretty confident that you should be able to program a PACE BMS with all the parameters required to be compatible with these cells.
  7. I'll take this with a teaspoon of Sodium Chloride.
  8. It happens. Looks like you probably have to send it in...
  9. They get generated the same way as recharge vouchers, so you probably won't find any that will work with your meter...
  10. Get one of these: https://signaturesolar.com/eg4-chargeverter-battery-charger-48v-100a-5120w-output-240/120v-input
  11. It sounds like your inverter is outputting DC at times. A surge arrestor won't protect you from that.
  12. The harmonics come from the high frequency slope you introduce when you switch on the element mid-wave. Think of it in the frequency domain.
  13. Yes, and their other switching losses are also much higher. But perhaps I should clarify a bit more. Modern IGBTs don't always require negative bias to reliably turn them off, but in the output stage of an inverter, you can get noise/spikes coupling through the miller capacitance that can turn them on again. So in that case you want to drive the gate negative (you probably would do that for a MOSFET in that application as well). Here we are talking about the output FETs of the battery BMS, so you don't expect that much noise, and it's also not a fast switching application (well not continuously switching). And lastly, it's a much lower voltage situation, so the coupling through the miller capacitance should also be much lower.
  14. N-channels are easier to manufacture -> cheaper. -5V is not needed, because it's not an IGBT.
  15. @JustinSchoeman Is correct on this. Many inverters warn against the use of phase angle devices like this in their documentation - in fact you can cause far more complicated issues than is covered here. Luckily most inverters handles these issues remarkably well, but in general phase angle triggering is a bad idea on this power level even if you are just on the grid.
  16. I don't think it's a requirement from SANS, as batteries are not indicated on the COC, but some suppliers require it for the battery warranty.
  17. It can only output 20A. Everything it reports above that (4600W at 230V) is internal losses. (the only exception is for periods shorter than 10s).
  18. No, it's not required. Adding a CT only changes the point at which reverse flow is stopped. Without it, only things connected to the output of the inverter will be powered by the inverter or solar. By adding a CT, you are able to also export power up to where the CT is installed. For example, if your geyser is not on the output of the inverter, by placing the CT before the geyser, will allow the inverter to know how much power it uses. With that knowledge, it can "export" just enough power to power the geyser, without exporting to the grid. (It does require the grid to be present)
  19. Look for high voltage panels and expect to pay a premuim. https://www.sustainable.co.za/collections/rigid-solar-panels/products/enersol-395hv-395w-high-voltage-solar-panel https://www.sustainable.co.za/collections/rigid-solar-panels/products/renewsys-prime-275w-high-voltage-solar-panel
  20. If there is a big difference in price, the cheaper one is probably not solid copper, which makes up the bulk of the cost. (Most likely copper clad aluminium.)
  21. That is the difference between silicon grease and silicone. Silicon grease will also eventually dry out because it's silicon particles of different sizes suspended in silicon oil (Polydimethylsiloxane/PDMS) that eventually evaporates at higher temperatures. Any silicon thermal grease should be acceptable, but I think the cheapest is if you can get some from a plumbing shop. https://za.rs-online.com/web/p/thermal-grease/2173835
  22. Yeah, I missed that part, that does not make sense...
  23. It seems that you might be conflating efficiency and power factor, they are not the same thing. To illustrate, here's a snippet from the first datasheet I found for single phase motors:
  24. Most likely it's just capacitive coupling between the cables and the conduit. Earth it and forget about it.
  25. Yeah, a pump/induction motor is usually rated for output power, so a 750W single phase pump usually uses around 1.1kW. It is also possible to overload a motor, but that will affect it's life. Luckily a borehole pump is well cooled (pun intended). 3 phase squirrel cage motors tend to be a bit more efficient, but it looks like the omnicalculator refers to "amperage" per phase.
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