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Thank you for the great forum, Safe Driving over the weekend. Sincerely Jason


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Everything posted by phil.g00

  1. Who can make this even simpler, with even more accessible components? 2 ltr coke bottle Water in plastic bucket garden hosepipe Bloudraad etc There are lot of innovative people on this forum who are sitting at home bored.
  2. Just to be clear, the limitations I stated above only apply when the Fronius downstream of the Victron AC out, not when it's grid side.
  3. From memory: 1. Victron states that exceeding the 1:1 rule will damage their inverter, no exceptions. 2. Victron also states that there should be a minimum of 5kWh of lead acid batteries/1kW of Fronius or 5kWh of Lithium batteries/1.5kW of Fronius. Caveat: I am crystal clear on 1. and just pretty sure about 2. This has to do with system being sized to absorb the surge of excess power during load and grid switching, (as the power control is not instantaneous). The bi-directional inverter has to have a big-enough charger and the batteries have to be able to take it as well, (even if they're already fully charged). Plenty of literature for this rationale on the Victron website.
  4. I can't find any pricing/specs on the WWW, about the RS smart 6000. I did see that it is not parallel capable "yet". I would be quite interested in this if it became parallel capable.
  5. I suppose there are any number of devices capable of this, but it may be moot, if regulations dictate that the biggest system you are allowed is too small anyway. Individual measurements are useful to discover your power guzzlers. Reducing power usage is the first step. ESKOM is adopting a new load-shedding approach, which they have stated will last eighteen months. Which means five years. (Formula = times 2 add 1 and allow) I'd be inclined to pull the trigger now, rather than just be ready to cope with load-shedding just about the time it is due to stop. The Victron system is good, having inherited the "cheap and nasty" initially, I wouldn't go back. There may be other good brands, but I can personally vouch for Victron. I consider solar panels to be cheap and a great investment that starts paying for itself from day one and carries on for 20 years +. On the other hand, I think batteries are a hole in the pocket, but a necessary evil. All aspects of batteries are often debated on this forum. My opinion is, if I was intending to eventually go off grid, I'd go lithium from the outset, if not I think I'd go for a 48V bank of SAGM 06 375 Trojans and try and get 8 years out of them.
  6. Load current (or if you like fault current) originates from a battery terminal and returns to the other battery terminal. Any single break in this circuit will prevent current flow.
  7. Sorry, if its directly bonded this measurement is not necessary.
  8. And the chassis E is now connected to the system E, I understand.
  9. OK, it appears that you have been involved in a capacity outside of this thread. I'll take it then, it has been clearly established that the chassis earth, the system earth and the system neutral are all directly bonded at the same potential. Now, it must be established that sufficient earth fault current will flow during an L-E and N-E fault. The inverter zero sequence source impedance will be different to the grid system. So it needs to be confirmed that the earth leakage protection still works for these two earth fault types when powering the system from the generator.
  10. I can't tell that he has taken these measurements from the information in this thread. I see that he has taken voltage measurements referenced to Earth, but what does he consider to be earth? That is why I was very specific in differentiating the generator chassis earth from the system Earth. If the measurements are from the system earth only, a V-0-V has not been ruled out and the generator chassis could be live.
  11. Is easy enough to find out. But, we have to be clear about where the measurements are taken. I doubt it is floating by design, V0V is a safety precaution of itself, when used properly. Under no load: L to the gen chassis = what voltage? N to the gen chassis = what voltage? Gen chassis to main system earth = what voltage?
  12. If you can physically move the centre tap earth to the to the neutral leg, it is no longer a V0V generator. But bonded means bonded, a hard-wired direct connection. That is what a standby generator has. What you seem to be doing is taking a V0V generator with a floating earth and giving it a high resistance earth reference through a light bulb. Then you are going substitute this neutral for the incoming properly earthed grid neutral. Nevermind, that a bulb can blow and that's a bad idea. This will limit the available earth fault current, so your MCB's wont trip for an earth fault, and it is doubtful that your earth leakage will work. So the difference between this set up and a standby generator, is you could burn your house down and shock people.
  13. Yes, you can make things work, but I don't like this at all. A V0V generator is a portable generator that is supposed to be used for double insulated handtools without earth leakage protection. It is considered safer because only half voltage is available to shock you in an earth fault and its considered a temporary risk. What you consider Neutral isn't neutral, but rather Live number 2. So you get things working, what's the problem? In standard house wiring the convention is that the neutral wire is at ground potential and we switch the live wire, using a V0V supply will mean all appliances are live even if switched off at the wall. People are used to an appliance that is switched off being dead. The MCB's in your DB box that should trip before that fire starts are all on the live wiring. Now a neutral to earth fault will pump away. Your earth leakage protection may work or may not, depending on a few things. There are no legal circumstances that a V0V generator can be hooked up to a fixed installation, with good reason. You need a proper standby generator.
  14. https://www.fin24.com/Economy/South-Africa/mining-companies-can-generate-own-power-without-licenses-matashe-20200203 Well, that didn't really take long at all. Next question Gwede, will the mines be limited to only generating a quarter of the power they need? I don't sense that from this article, because they'd still be at ESKOM's mercy and the mines are gunning for power independence. Now if the power system can handle that, why does domestic solar need to limited to 25% of its supply MCB? It may be true that if we all got solar then the system may be in the crap in the case of a frequency event. But, right now we don't all have solar and the power system is in the crap on a daily basis because of a lack of generation already. Let's cross the first bridge first.
  15. Consider using Unistrut. It is very flexible in its application.
  16. I think the new philosophy is "if we aren't load-shedding there isn't enough plant out for maintenance". SA lifestyles will have to adjust for a few years, I actually think this is a sensible approach. I hope the politicians allow this, and stay out of ESKOM's engine room. The only thing I want politicians to realize is ESKOM is load-shedding after 9am, and that's when solar could provide a dig out, if they cut through the red tape. There are people who are forced to spend money for limiting equipment so as to not export power into the grid. Safety-wise, there must be a compromise between the free electricity illegal connections in Soweto and the hyper-expensive Rolls Royce compliance rules of domestic solar that can benefit the country in these times. A stroke of a pen and they could use pre-existing generation in the very short term.
  17. I think this past week represents the new load-shedding model SA will have to get used to for a few years. It had an entirely different feel to the "whackamoley" crisis load-shedding, to now being a planned operational decision. It'll happen during off peak periods to minimize economic impact and reduce the operating costs of diesel plant, and if there enough generation to cope, something will be taken off the system for philosophy maintenance. Probably a good thing in the longer term to bite the bullet and get the real issues sorted instead of these present day sticky plaster fixes. Looks like Andre has said that if they can't avoid load-shedding and can't afford the diesel then ESKOM is going to at provide some certainty, convenience where it can, save some money and get the maintenance issues fixed. People wondering whether to pull the trigger on a solar hybrid system may as well, because this style Stage 2 load shedding will become the norm for a while, methinks.
  18. Why? unless your drawing is inaccurate? No Considering you didn't know basic 3 phase principles, this is a good idea.
  19. If you set the built in timer to be permanently on, then you would still have a thermostat. Then you could supervise the supply with whatever external timer you wanted. That way you'd have a more flexible timer and a thermostat.
  20. This is a shade cheaper: https://www.alibaba.com/product-detail/RHENES-high-quality-30mA-100mA-300mA_62027700118.html?spm=a2756.order-detail-ta-ta-b.0.0.2c2e2fc2KDWgA4 You only need the type B, where there is a possibility of a DC earth fault. In other words where there isn't galvanic separation between the AC and the DC circuits. This happens with transformerless grid-tied inverters. Where there isn't a link between the AC and the DC, the normal 30mA RCD will suffice. However a 30mA Type B would still work in a pure AC circuit as well, it just has a extra measuring element for DC. As to your set up as shown, I'd go for single phase RCD's, one on each phase. Although I might be inclined to have one per house, after the changeovers, if you are not using L2. They should be downstream of the supply and upstream of the first instance of power usage.
  21. By the way, I wouldn't do things this way if I was planning to use a single phase inverter on a three phase system. What I would do is take the three phases everywhere, and from the outset I'd be pretty disciplined about what was on each phase. Along the lines of L1 = the loads I'll do without when load shedding, L2 = the critical loads i want to stay on during load-sheding, L3 the loads I want to turn on to coincide with the noon production peaks so I am not nett exporting. But this might be quite a daunting task with a large existing setup.
  22. This one has a transformer and is isolated from the AC, but the linkage will still be there once you put a grid-tied Fronius downstream of it.
  23. 1. You will get a host of answers on this point, but I believe your grid supply earth should be tested and if it is a good earth it should be hard-wired and distributed to all other the places you show an earth spike. There should not be earth spikes all over the place, this can cause problems. If you have to use a spike, use sufficient spikes close to one another and measure to make sure its a very good earth and everything gets hard-wired back to there. Additionally you should earth the PV panel frames to your system earth with a transformerless inverter, like a Fronius. 2. Yes, if wire size is same as the live phase. (What I don't like about your drawing is that DC+ & DC- , are the same colours as L# & N). 3 & 4. Yes and No, you can electrically, with the caveat that I have my doubts about getting things approved, but there are enough people on this forum who can quote you the domestic regulations. 5. Yes, if you use a transformerless inverter, then there is a direct connection to the DC side of things from the AC side. So besides you needing earth-leakages, you now need a special AC & DC earth-leakage. A Type B RCD.
  24. Assuming this circuit is one of those that can chop even after the peak, then theoretically, there may only be a range where it is bad. Nearly full on and nearly full off, you will probably get away with. When its chopping around the peak of the sine wave,( half-power) I'd reckon it'll be at its worst. I haven't gone into these too much though, so I might be wrong.
  25. What do mean by "can't"? Do you mean "shouldn't"? When you shouldn't you will have to deploy some sort of gateway control in addition to the grid-tied inverter. Otherwise, it "can" and it will.


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