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Calvin

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Calvin last won the day on November 30 2020

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  1. Calvin

    Kodak inverter

    Hi Darryl, One thing to add to 87's excellent reply: The Kodak includes an 80A MPPT (useful if you ever want to add a few PV panels), the Multiplus does not. However, whilst some Voltronics inverters claim Pylon BMS integration, it is in practice more "marketingware" than software. - you need some external system (eg ICC) to properly manage it. If you like things to "just work" (and are prepared to pay the premium) Victron seems a good choice - if you like getting your hands dirty go for Voltronics.
  2. After your 12V battery with charger, just put in a small DC-DC voltage converter (something like Voltage Regulator [email protected] Vin 10.5-38 V - Micro Robotics) and power the camera straight off the 9V output. No need for an inverter or the camera's power supply adapter.
  3. Alternatively, a business opportunity to sell camouflage patterned PV panels....
  4. I believe that he is talking about the City of Cape Town's regulations. I understand that they use aerial/satellite imagery to check for the presence of PV panels - off-grid systems must be registered so that you don't have to use the "Decorative Roof Shades" excuse . See https://www.capetown.gov.za/City-Connect/Apply/Municipal-services/Electricity/apply-for-authorisation-to-install-a-small-scale-embedded-generation-system
  5. When connecting string in parallel to the same MPPT the one thing they all have in common is the voltage. That means that you need each string to have (close to) the same optimum voltage. Looking at the specs of these panels, the 250W has a Vmp (optimum operating voltage) of 31V, the 345W is 35V. Perhaps you could reconfigure this way: take the existing 15 panels and make 2 strings of 7 each. Put in parallel the 6 x 345W panels. That way you will still have a small mismatch (217V vs 210V) but it is not too bad. Better would be to find 6 panels with Vmp of 36V (total 216V) - th
  6. I have been trying to make sense of this post. Please help. I assume that the 5M you refer to is 5MW (megawatt). I assume that 40M is in fact 40m (metres), and 8M is 8m. I further assume that the 605W you refer to is a 605W panel. The only one I can find is a Jinko RS600M-120HC - they measure 2172mm x 1303mm. You could fit a theoretical maximum of 113 into an area 40m x 8m if you packed them without gaps to avoid shading, more like 40% of that in practice. "Easily 120" would be a stretch - perhaps I have misunderstood you? By 7.2 KWhr I assume that you mean 7.2kWh. I do no
  7. MW is Mega Watt, a measure of power not energy. So, 10MW would be 240 MWh (240 000 kWh) per day. It is quite a lot.
  8. The Axpert King is an "off-grid" inverter and is not capable of feeding in to the grid. For this functionality you need to look for inverters that support "grid tied" mode.
  9. You're welcome - nice to find someone with an open mind.
  10. Really good question. I will wire up my pool pump through a power meter tomorrow and check if I can repeat that. Will report back. So, this morning I re-wired my pool motor so that the pump runs through the plug (meant for the chlorinator) so that I can run it through my Kill-A-Watt meter. What I found was: Maximum flow: (no creepy, multiport valve on bypass) 855W Filter flow (no creepy, multiport valve on filter) 830W Zero flow (multiport valve on closed): 635W This is pretty much what I expected - theory confirmed by experimental result. Q.E.D.
  11. Really good question. I will wire up my pool pump through a power meter tomorrow and check if I can repeat that. Will report back. That one is easier. As I said earlier, most people understand positive displacement pumps intuitively, and centrifugal pumps not at all. Perhaps they write what they believe should be true. Untruths has been known to flourish on the WWW....
  12. I have both studied and lectured thermodynamics at UCT, but unfortunately the field we are talking about here is in fact called Fluid Dynamics. But anyway, you are mostly correct. Everything @DeepBass9 says is true for positive displacement pumps: if the filter gets dirty, the pump has to pump "harder" to force the water through. The flow stays approximately constant, pressure goes up, hence power goes up. A centrifugal pump on the other hand is essentially a constant pressure device. The static head (pressure at 0 flow rate) is proportional to the square of tangential speed of th
  13. Afraid not. I know that it is counter-intuitive, but it is absolutely the case. If you find it difficult to believe, wire up a KillAWatt or similar meter to your pump and see for yourself.
  14. @MKRandburg To be perfectly safe, have a flow control valve in the main return pipe to the pool as well as in the pipe through the heater. (I assume that the outlet from the heater drains directly into the pool) Start up with both valves fully open. Then, close valve for heater until water coming out of it is say 5-10C higher than pool water (in full sun). Then, if necessary, you can close the main return to the pool a bit if the pump motor is running too hot (or if you do not get sufficient flow through the heater). If you have a pressure gauge on the pump outlet you can use
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