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Surge

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  1. Thanks Steve. I'm glad Sunsynk are investing R&D in their Connect system opening the way for some home automation without needing to roll one's own solution. I managed to find a bit about the Smart Switch on one of Keith's recent Youtube clips. Evidently a Wifi enabled AC smart switch will be provided for free with all new Sunsynk inverters beginning around the March 2023 timeframe. I presume existing customers will be able to purchase them separately if they already have a Sunsynk inverter or require multiple smart switches.
  2. Based on Sunsynk's remote control/monitoring solution (Sunsynk Connect) there appears to be an option to integrate some sort of smart switch. I presume this will allow one to control a smart switch based on inverter parameters opening the way for some automation like switching off loads when battery SoC is low or switching a light on when mains fails to indicate grid down. I cannot find anything about this smart switch online. Does anyone know what hardware is used for the smart switch? It requires one to enter a serial number and key like one does when setting up a Sunsynk Gateway (Wifi dongle).
  3. I went with 12 x JASolar 540W panels (two strings of 6) because they fit the available roof space better. I couldn't get three rows of 460W panels and two rows of larger 540W panels in landscape orientation both maximized the area covered as well as reduced the cost of the mounting kit. The string voltages are only 240V so it may not be in the max efficiency range of the Sunsynk 8KW MPPT controllers but I really don't feel that it is such a big issue. Weather plays a far bigger role than MPPT efficiency curves. Just use what fits your roof layout and stay within the electrical specs. If a manufacturer came along with a 30% efficient panel then sure, that would be a game changer but at the moment solar PV panel effiencies are so close to each other it makes little sense to pick the biggest panels one can buy simply because it sounds better.
  4. I haven't installed solar yet but I was thinking about this whole earthing issue and it seems to be overly complex with regards to regulations. I am wondering if an isolation transformer would not be simpler option and avoid violating any regulations? In other words install a 230 to 230 VAC transformer between the supply/grid and the inverter with it's own supply DB (and RCD if required). Then permanently ground the output of the inverter to earthing spikes so that the downstream RCD in the main DB always works on the local earthing point. Then there is always an earth reference even though it is not connected to the grid earth. If one is practically off-grid and only needs say 1kVA to top up batteries on cloudy days then the "shore power" to be imported from the grid can be limited on the inverter settings. This keeps the isolation transformer small and cheap enough. It shouldn't matter if the two earths or neutrals on each side are not referenced to each other. If Eskom/Muni screws up and has a floating neutral on their side (I've seen that happen more than once) it also won't cause any issues on the inverter side because the voltages are decoupled and float relative to each other. Would something like that work and still be legal or is there specific wording which forces one to carry the grid earth into the main DB for earthing requirements?
  5. It's not a secret. Most municipalities make a large portion of their revenue through electricity resales. From what I can find online, Eskom sells electricity to direct customers at around R1.16/kWh. The municipalities probably get it for less. The municipalities mark it up to R2.00+/kWh with their fees, tariffs, IBT scales and other NERSA approved BS. Other than some minor distribution costs it's like printing money. Check this out from the Tshwane Draft Bylaws for Embedded Generation: 6.10 Risks 6.10.1 Economic Increases in the price of electricity and the rapidly decreasing costs of EG solutions will impact negatively on municipal revenue. In future this may lead to grid defection, with serious revenue consequences. It is therefore important that the City creates an EG connection environment that is customer-friendly. And: 6.11.1 Revenue There could be a revenue dip due to the introduction of EG, in particular in the residential sector, and this should be rectified by appropriate tariffs. Tariffs need to be adapted due to EG being part of the energy mix. http://www.tshwane.gov.za/sites/business/Bylaws/Draft%20ByLaws/28.%20Proposed%20Embedded%20Generation%20Policy%20to%20support%20and%20formalise%20procedure.pdf&ved=2ahUKEwil4PudoIXtAhVipHEKHVb9CG8QFjABegQIBBAB&usg=AOvVaw1cks5-EcFHKgeY7OFNVhpD The thought process and reasons are blatantly clear.
  6. What is the Renusol storm washer used for and where does it go? I can't find any depiction of how it's used online. Is it a fancy seal that is sandwiched between the hangar bolt and roof sheet to help prevent leaks? If so what is the purpose of the rubber seal on the hanger bolt in that case?
  7. Excellent! It's seems to be a key feature to avoid a floating neutral when Eskom dies.
  8. Isn't there a difference between Deye and Sunsynk when it comes to contacts for an earth-neutral bonding relay with the Sunsynk having the feature built in? I recall reading something like that somewhere.
  9. It's not really a Victron issue. I suspect that other brands of inverters would do the same to Pylontech BMS' on initial startup. Thanks for the recommendation about Sunsynk though. They look like really good value for money. Unfortunately finding a solar installer who supplies Sunsynk seems to be a problem - they all seem to be selling Deye kits which appear to be a watered down Sunsynk (from what I've read on Power Forum).
  10. Yes, that's exactly what I mean. The once off inverter startup current trips the BMS (something like 200A surge when switching on a Multiplus II 48/5000). So the "normal" solution is to build a pre-charge circuit? I've just never seen this mentioned in any kits being sold. Thanks for the good idea. Seems like a very affordable way to solve the issue.
  11. At some point in the near future I'd like to set up a hybrid grid connected system with minimal battery backup. I want to use minimal battery for purely backup/UPS to keep the costs down but what concerns me is that it seems that some hybrid inverters like Victron have a very high start up current which trips the BMS overcurrent protection on Pylontech's (and probably other lithium packs too). The Victron forums are scattered with comments like one needs a minimum of 3 x Pylontech US3000 batteries for a Multiplus II 48/5000 system in order to not trip the BMS overcurrent protection mechanism. That prevents the idea of having minimal battery capacity for lighting, TV, alarm, etc. and makes the system very expensive. Victron even have a page describing the requirements. https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom The Multiplus II 48/3000 is too small for my needs so downsizing to a smaller inverter in order to have less batteries is not an option. It seems to be a rather silly restriction in my opinion. Why can't Victron build in a "slow-start" mechanism to limit the start up current of their inverters? As this is only a startup issue it seems that if one can pre-charge the capacitors in the Victron before switching it on it would solve the problem. In fact I just stumbled upon such setups. https://community.victronenergy.com/questions/38299/phoenix-inverter-2.html What I'm curious about is why I don't see this issue mentioned in most of the DIY builds or even the kits being sold locally. How do other people get around it? Do other hybrid inverters have the same issues or does everyone build their own pre-charge circuits? I must be missing something.
  12. The closest thing I can find and "off the shelf" is this https://www.sustainable.co.za/sustainable-580wh-power-box.html It uses LiFePO4 batteries and a decent hybrid inverter from Victron. You can add solar to it later and even use ESS. If you want to DIY you can probably source the components cheaper by hunting a bit. e.g. The BlueNova BN13V series of LiFePO4 batteries are cheapest on Takealot. I suspect that they are being sold directly via BlueNova so you cut out the middleman. I'm sitting on the fence because I can go the cheap 12V route and just use a LiFePO4 charger with single 280Wh LiFePO4 battery to power the ADSL router, wireless AP and lighting. That would give me about 6 hours of backup power for under R5000. Adding the 230V inverter option adds a lot of cost and instead of using the TV I can just use a smartphone to stream Netflix (I don't use Monochoice) or surf the web. Choices ... choices ...
  13. I'm not sure if the following is legal in terms of keeping municipal and rainwater/greywater separate but it's something I'd do without it bothering my conscience. If you want to make the change over system automatic you could install a ball float valve (like the ones in your toilet cistern) inside and close to the bottom of your rainwater tank and connect it to the municipal supply. When the rain water level in the tank drops to say the 25% capacity the ball float valve will open and maintain the level at 25% using municipal water. Just determine where the crossover point needs to be by moving the ball float valve up or down inside the tank. Your booster pump will never run dry unless there is no rain water and the municipal supply is off and you'll never need to worry about manual intervention. Alternatively install a float switch in the tank so that the booster pump can't run when the tank is below a certain level. The ball float valve prevents rain water from feeding back into the municipal supply although the municipal pressure will almost always be higher than the head of water in the tank (except when there are water outages or if the tank is on a very high tank stand in which case you wouldn't need a booster pump). Regardless it's not possible to accidentally feed rainwater back into the municipal supply using a decent float ball valve. N.B. Just make sure that the outlet from the ball float valve is in clear air (not underwater) when the valve starts to open. This prevents siphoning/feedback into the municipal supply when the municipal supply is off and the level in your tank is in the "top up" area. You can do this by bending the float arm downwards or installing the valve at a tilted angle so the float is lower down than usual.
  14. Thanks plonkster, that answers my questions. So fuses on battery cables, current limiting circuit breaker on mains input (to protect cable from wall socket), RCD on output to trip if there is an earth leakage + current limiting circuit breaker on output to protect output cable.
  15. I'd like to build a small, mobile battery, backup system (UPS) using a Victron Multiplus 500VA 12V inverter/charger with LiFePO4 batteries just to ease the pain of load shedding. I've ruled out the Ellies/Mecer units since they use lead acid batteries which do not last when deep cycled frequently (I have friends who've learnt this the hard way). What I don't understand is how the Ellies/Mecer/Sustainable battery backup systems implement earthing/grounding and if they are protected by an earth leakage unit. I don't see any mention of earth leakage being present on these portable UPS units. How do they protect against accidental electrocution when the inverter is running the load and there is no earth leakage in-line? The other thing that is not clear to me is whether the Multiplus 500VA to 1200VA units are bi-directional inverters or not and what isolation is present when there is a grid failure. They have a UPS mode which I presume will prevent any feedback to the grid but that's not an assumption I'd like to take for granted. Does UPS mode on these smaller units provide sufficient isolation from the grid or does one need to install isolation circuitry and possibly go down the ESS path like the bigger Multiplus II 3000VA+ models? I don't see any mention of additional mains isolation present on the Sustainable Power Boxes which also use the Multiplus 500VA/12V and 1200VA/12V inverter/chargers.
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