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NigelL

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  1. Thanks
    NigelL got a reaction from Revnge_SevnFold in NOARK Ex9BP-JX 2P Wiring confirmation.   
    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. Haha
    NigelL got a reaction from RaeesD in Basic load shedding solution   
    Reminds me of the following XKCD webcomic 🙂

  3. Like
    NigelL got a reaction from zsde in How much should Solar system be producing   
    @Scorp007 Is correct - you can normally add extra battery units in parallel to get extra capacity. Your installer should be able to advise you on this.
    Note that you have a large solar array (4860Wp) and a small battery (3.7kWh). This means that the solar panels can possibly fully-recharge the battery by mid morning - long before the max power from the panels is achieved. After the battery is full, the solar panels will just supply the house loads (assuming no feedback to the grid).
    It would be useful to see the PV-Yield over a 24-hour period (on a sunny day). See my PV-Yield from a few days ago (I have 9 x 330W panels = 2970W).

  4. Like
    NigelL got a reaction from Charl Yazbek in 3-Phase DB Board Rewiring in Prep for Solar Installation   
    The incoming phases all are referenced to a common neutral, however each Earth Leakage device requires its own separate neutral bar for all devices connected "down stream" of the E/L unit.  As Johan mentioned, one can have an "interesting time sorting it all out". Especially if one has an older house where the electrics have been extended by multiple parties over the years.
    The real fun starts when you have two circuits, that need to be separated, and they have a shared neutral wire in some well-hidden junction box.
  5. Thanks
    NigelL got a reaction from Charl Yazbek in 3-Phase DB Board Rewiring in Prep for Solar Installation   
    Normal residential 3-phase electricity meters will correctly record total power usage even if you only use power on a single phase. It is recommended to divide the circuits/loads across the 3 phases so that there would be roughly the same load on each phase if all circuits/loads were in use, but in practice one never uses all loads at the same time.
    I have a 3-phase supply but many of the houses in our street have a single phase supply. It looks like they try and balance things out by connecting houses, with single-phase supplies, roughly evenly across the phases.  We have had a couple of occasions where one phase has been down and only a few houses in the street were affected.
    I have also installed my system on a single phase and have not run into any issues.
    EDIT: The municipality generally wants the maximum possible current drawn on each phase to be roughly equal. It does not matter if you are currently using a relatively low un-balanced current.
  6. Thanks
    NigelL got a reaction from isetech in Termonology   
    Hi @isetech
    A great source of info is available in the following pdf https://www.victronenergy.com/upload/documents/Wiring-Unlimited-EN.pdf
     
  7. Thanks
    NigelL got a reaction from Gnome in AC and DC cable wiring CoC   
    I think the key to this is that one should provide separate channels for different services (e.g. AC wiring and DC Wiring) where the channels ensure both physical separation and an insulation barrier between the different services. See the following extract from SANS 10142-1:2017 Ed2.

    I believe that the split-trunking, as mentioned in my previous post, meets these requirements by implementing two separate channels.
  8. Like
    NigelL got a reaction from hoohloc in AC and DC cable wiring CoC   
    I am not aware of any officially published standard that says this.  There was some discussion about routing solar cables in metal conduit when running over longer distances (e.g. between buildings etc.). The split trunking is widely used for routing AC and DC cables, in solar installations, in many countries.
  9. Like
    NigelL reacted to DeonVDW in New tool: monitor individual cell voltages on BlueNova batteries   
    I've created a small application to log the output from the BlueNova battery monitor (battery-ip:9000/) to a database - this allows you to create graphs like the attached one. My goal is to perform long-term monitoring of the battery health beyond a simple Health% value, and well, because it was there :)
    The project page is at: https://github.com/deonvdw/BlueNovaBatteryMonitor. Also contains some details about hooking up your BlueNova battery to fixed Ethernet using an USB-Ethernet adapter.

  10. Thanks
    NigelL got a reaction from PierreJ in Victron Multiplus II Temperature Warnings   
    The "overload" warnings only mean that the AC loads are larger than the Inverter maximum power output. In this case the power difference is sourced from the Mains input. As far as I know, this is quite normal in an ESS setup and is purely "informative". The temperature warnings are not normal and should be investigated.
  11. Thanks
    NigelL got a reaction from Ingo in NOARK Ex9BP-JX 2P Wiring confirmation.   
    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
  12. Like
    NigelL got a reaction from PlanB in 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).    
  13. Thanks
    NigelL got a reaction from Jaco De Jongh in Wire Management of PV on Tiled Roof   
    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. 
  14. Like
    NigelL reacted to The Bulldog in Lock down solar projects   
    So how are you doing with your solar system during lock down ?
    Perfect time for me do do what I wanted to do for some time but never had the time for. To recap - got three 5KVA multies on a three phase feed with a Solis 15KVA three phase grid tie with 10KWp of panels on the roof.
    I "stole" one of our MX1 aircraft EFIS flight instruments and repurposed it a bit. This is the original prototype of the MX1 EFIS intended for low cost applications. Normally it would be fitted in an aircraft cockpit and gives you all of the primary flight information (altitude, airspeed, attitude etc), does the autopilot, navigation, engine monitoring and so forth. Pretty much an all in one glass panel. Made in Somerset West and exported around the World (one of many models we do).
    Anyway, at its heart it is a STM32H7 processor with a LCD touch screen. I took the normal EFIS software and threw out a million or so lines of code to end up with a skeleton but functional system and hacked around the Solis and Victron communications buses and connected these to the MX1. The MX1 software is largely user configurable - you design your own displays from provided items so I added all the various bits from the inverters. You can do up to 9 screens - you select which screen you want to view using a rotary control. Here is my "main" screen. My system is approved to feed in so I want to see how I am doing. This is the last few days (but we had some rain and overcast so I am a bit negative on the financial side but still feed in far more than I use). Other screens are dedicated to solar production stats, daily stats etc. The graphs show a day at the moment but the system stores up to a year of data and you can scroll through each day and touch the graph to see what you were doing at that point in the day.
    The MX1 is also able to control the inverters including throttle the solis if needed. Using ESS I can shunt power from one phase to another or utilize the battery in whatever way I please to optimize the system as a whole. It can also control switching units via Wifi to switch loads in and out depending on conditions. For example you could setup such to put excess power into a geyser depending on water temperature and potential PV power which the MX1 can calculate (if the Solis is throttled). These switches then work in a priority chain with power export being the last item as that is the most inefficient way to use the power (COCT pays peanuts for the power). 
    Fun project so far - still work in progress of course - the more I add the more ideas I get.
    Pic below shows my current main screen (Battery stuff needs work - still need to connect to BMV). Graph shows import/export of power during 24 hour day - yellow line is current time - into to the right of that is yesterday (so it always shows the last 24 hours). 

  15. Haha
    NigelL got a reaction from Chris Hobson in Basic load shedding solution   
    Reminds me of the following XKCD webcomic 🙂

  16. Like
    NigelL got a reaction from ___ in Grid tie inverter and ac coupling   
    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. 
    However, it is worth taking note of section 10.3 of their Supplemental Contract:
     
    Electricity Consumptive Tariffs 2019-2020.pdf
  17. Like
    NigelL got a reaction from mmacleod in Basic load shedding solution   
    Reminds me of the following XKCD webcomic 🙂

  18. Like
    NigelL got a reaction from mmacleod in Solar power vs PV Power   
    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.
  19. Like
    NigelL got a reaction from ___ in Basic load shedding solution   
    Reminds me of the following XKCD webcomic 🙂

  20. Like
    NigelL got a reaction from ___ in Good Quality Basic Solution Recommendations   
    It looks like sustainable.co.za also do higher-power versions which have higher-capacity batteries - e.g. https://www.sustainable.co.za/sustainable-1000wh-power-box.html
  21. Like
    NigelL got a reaction from Fuenkli in Circumventing the COCT 3.5kVA limit   
    If one has extra space in the DB, one can install an extra changeover switch so that the non-essential loads can be switched over to the Inverter Output.  You must then carefully manage the loads so that you don't trip the inverter, but this could be really helpful in the case of an extended power outage.
  22. Like
    NigelL got a reaction from PJJ in Circumventing the COCT 3.5kVA limit   
    If one has extra space in the DB, one can install an extra changeover switch so that the non-essential loads can be switched over to the Inverter Output.  You must then carefully manage the loads so that you don't trip the inverter, but this could be really helpful in the case of an extended power outage.
  23. Like
    NigelL got a reaction from ___ in Circumventing the COCT 3.5kVA limit   
    If one has extra space in the DB, one can install an extra changeover switch so that the non-essential loads can be switched over to the Inverter Output.  You must then carefully manage the loads so that you don't trip the inverter, but this could be really helpful in the case of an extended power outage.
  24. Like
    NigelL got a reaction from ___ in Smart Charger with Victron BVM712 BT monitor Routing   
    Hi OCD75
    The BAT terminal on the Shunt should be the only thing connected to the Battery Negative. All other "negative" connections (loads, chargers etc.) must be connected to the "Load" side of the Shunt. If you don't do this, the BMV712 shunt cannot properly measure current into/out-of the battery - and will then give an erroneous reading for the State of Charge.
     
  25. Like
    NigelL got a reaction from PJJ in Smart Charger with Victron BVM712 BT monitor Routing   
    Hi OCD75
    The BAT terminal on the Shunt should be the only thing connected to the Battery Negative. All other "negative" connections (loads, chargers etc.) must be connected to the "Load" side of the Shunt. If you don't do this, the BMV712 shunt cannot properly measure current into/out-of the battery - and will then give an erroneous reading for the State of Charge.
     
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