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NigelL

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NigelL last won the day on November 28

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  1. I found this useful document that describes the correct wiring of DC Circuit Breakers in PV applications. Discussion-Paper-Correct-Wiring-of-Double-Pole-DC-Breakers-LVL2-131210-v2.pdf
  2. As far as I remember, the Efergy monitor has a setting where you enter the Mains voltage. If this is set above/below the actual mains voltage, the calculated energy will be correspondingly above/below the metered value. Also check whether the clip-on current sensor is properly attached. The two sensor surfaces must be lightly pressed together (i.e. no gap) and have no cracks, chips or dirt between them. A third possibility is that the Effergy monitor may not accurately record very low-current loads (standby current of TVs, PSUs etc). This can easily add up over a couple of months.
  3. This results in a somewhat unexpected consequence - your solar panels will run slightly cooler as one draws more electrical power from them. See https://www.sciencedirect.com/science/article/pii/S2211379716301280
  4. Hi Bobster While your solar panels are capable of generating 3kW - they only deliver the amount of power that is required by your system. Practically, this is done by your solar charger limiting the amount of current drawn from the solar panels. Sunlight energy on solar panels is normally converted into a small amount of electrical energy (e.g. 17%) and the remaining power (83%) is dissipated as heat. When you stop drawing electrical energy from the solar panel, 100% of the sunlight energy will dissipated as heat. So you are correct - the solar panels are one very large heatsink
  5. NigelL

    BlueNova Check

    A 4kWh Lithium Battery is undersized for a 5kW Inverter. Take a look at the Pylontech battery recommendations for example. You should also typically set your minimum SOC to around 30% - although this depends on how much battery reserve you need to keep for loadshedding. I have a 12kWh BlueNova battery with a 3kW inverter so I generally only discharge to about 65% SOC overnight. My battery appears to have a larger capacity than advertised - cell voltages still looked okay when I once discharged it close to the full rated capacity (as measured by BMV712).
  6. I am not familiar with the HXE310-P meter, but unless it's a bi-directional meter, it is highly likely you will be charged for pushing power back to the grid - as though you had used the same amount of power from the grid.
  7. The good news is that you are unlikely to have any problems with a grid-tied setup (this can sometimes result in low-power/short-duration feedback to the grid - causing some prepaid meters to trip). The bad news is that you are likely to be charged (i.e. units deducted) for any power that you feed back to the grid!
  8. South African Standard SANS 60364-7-712:2018 (which is based on the international standard IEC 60364-7-712:2017) - titled "Low voltage electrical installations - Part 7-712: Requirements for special installations or locations — Solar photovoltaic(PV) power supply systems" does not have any requirement for metal conduit. Section 712.522.101 states that "All non-metallic cable management systems exposed to sunlight shall be of a UV resistant type" I think that SANS 60364-7-712:2018 is likely to be the "applicable regulation" on this issue, but I am not 100% certain.
  9. For some useful info on solar panel performance, based on installation angle, orientation and your location, see https://www.pveducation.org/pvcdrom/properties-of-sunlight/solar-radiation-on-a-tilted-surface Edit: This page is probably more useful - https://www.pveducation.org/pvcdrom/properties-of-sunlight/calculation-of-solar-insolation
  10. The City of Cape Town introduced a second Feed-In tariff that is a bit more user-friendly - see the "Residential Small Scale Embedded Generation 2" in the attached document. This works out at R85.00 more than the standard monthly "Network Access" fee, so you need to feedback 108kWh/month or roughly 3.6kWh/day to offset this increased fixed cost. The only way this will work to your financial advantage is to maximise your feedback during summer months to try and offset your increased usage during winter months. Remember that you cannot be a net-exporter over any 12-month window.
  11. Honestly, I think they forgot about my application until I followed up with them in September. They quoted me a 2 week turn-around for a decision on the permission to install, in May. I was not in a hurry for the paperwork since the installation was already "completed" prior to the application . The City of Cape Town require you to sign a "Supplemental Contract" that basically lays out the rules and options available. Max inverter power Power Export or Non-export options Bi-directional energy meter (if exporting) Costs and Tariff structure (depends on whether one
  12. Another point to keep in mind is that PV Panels generate optimal power in sunny and cold conditions, whereas solar water panels work best when it is sunny and hot.
  13. The summary version: May 2019. Submitted my application September 2019. Inspection of premises October 2019. Sign and hand-deliver the required "Supplemental contract" October 2019. Permission to Install letter received. Feb 2020. Commissioning approval letter received (dated Jan 2020). I think that this would have gone a lot slower had I not followed up/queried the progress.
  14. Victron definitely support BlueNova batteries - see https://www.victronenergy.com/live/battery_compatibility:start . BlueNova batteries, with newer BMS firmware, also support the DVCC feature - it works well on my system
  15. Reminds me of the following XKCD webcomic
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