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phil.g00 last won the day on September 21 2020

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  1. Overheating generally happens for 2 reasons: 1. The cross-section of the cable is too small for the amount of current you want it to carry. 2. A loose connection. For 1.) There are a host of current capacity tables on the www. for 2.) It is normally localized heating at the poor connection. ( It's always nice if someone can lend you a Flir).
  2. Read the specs of your panel, there is a temperature coefficient for voltage, meaning the Voc will rise as it gets colder. If it gets cold enough the Voc will exceed 50V, meaning that 5 panels in a string will exceed 250V. You may get away with it on the coast, but generally in the low minuses it exceeds 50V.
  3. No, you will exceed the voltage rating of the MPPT if it gets cold. Normal slope I am referring to your roof pitch slope, vertical is self-explanatory. Not many people go vertical. Probably in this ballpark, but I think you are being slightly optimistic with these numbers.
  4. I once looked at pool heating and I was surprised how effective this was, from memory it was something like the heating capacity could be down-scaled 25-30% with one of these. Definitely, first stop when considering pool heating or just keeping it warmer longer.
  5. From graphs I am going to go with a daily peak power from PV as 150V @35A, say a nominal peal power input of 5250 Watts. (In line with what you said). I'll guess your charging voltage is say 55V and you have 100A at that voltage, so you are capable of handling a peak of 5500W'ish. So you have around 250Watts of headroom in your present configuration. Which isn't much. Essentially you can't add any panels (N or normal slope E/W) that add to your noonday peak. You won't have problems, but you won't reap a whole lot of benefits either. So your options to harvest more power in
  6. You cannot exceed the voltage rating of the MPPT, this is a hard limit. In your case I believe 4 panels in series will be the maximum length of string. Exceeding this voltage will damage the MPPT. The number of strings is a different story, this is the current output limit superimposed on you by the MPPT. It is not a strictly a power limit but depends on your battery voltage. It might be known as a 48V system, but the charging voltage may be 10V higher. It is a current limit, in your case it is 100A. If you added another North-facing string that peaked simultaneously with
  7. You will need to add matching strings if you want to use the same controller.
  8. Vertical panels wont add to your noon peak, think about it. They will add to generation before 10:00 and after 14:00 though on a clear day. A thumbsuck: With an extra 1200W of vertical due East panels, I'd guess power would start at first light, maybe 500W within half an hour of dawn YMMV. Another thumbsuck: On an overcast day they will contribute all day long at probably around 3% of rating with your North -facing panels at about 5% of rating. So you are going to get very little from your panels when it is overcast. The best orientation for overcast days is p
  9. Some reviews here: https://ie.trustpilot.com/review/tesup.co.uk Hugh Piggott of Scoraigwind literally wrote the book on small wind. I would not discount his views out of hand. He thinks VAWT are toys. However, even with a great turbine you need wind, if you don't live in a really windy place you don't have it. If you add vertical E-W panels, you can produce watts earlier and later in the day using the same charge controller. They wont produce energy at night, but it is still at a time when your present set up isn't generating. Maybe not a lot more watts, but I'd wager
  10. I have heard that there substantial difference in the better quality of the new range of EPEVER, just webtalk. I have also heard of issues with the older range ( but not very many). Seen here: https://www.epsolarpv.com/product/44.html I have no affiliation and no first hand experience.
  11. I don't use Victron MPPT's, but I am considering them. If possible, can you quantify "a lot faster" into some practically expected times of DC vs AC coupled responses please?
  12. You are lucky indeed, if the rest of the country twigged on this could be a good thing. There are many opinions about safeguard limits and potential power gluts if that is done though. I say SA starts to manage the problems it has and not deal with the problems it could potentially have. It would actually be nice to have to deal with the issues we could maybe develop in the future, if we relaxed domestic solar restrictions. I have had 5 x 2 hour load-sheds between 10:00 and 14:00 in the past 7 days. That means at peak solar production times ESKOM couldn't meet the national
  13. I do have one of sorts but this had to be factory pre-programmed for the relative times. It then knows where it is because it has its own GPS. Google: GPSlightlock. I think the astronomical timers are much cheaper though, and they look to be freely programmable.
  14. I'd better add the caveat that I don't use Lithium batteries. Lithium batteries do require that all Charge controllers do switch off together for high voltage battery protection. This is easily implemented with a contactor on the solar side of the MPPT. Break the PV side, as most manufacturers recommend you switch off PV input before the battery. In practice, I find it doesn't matter if you have your Voc ratings right, but you may as well do it the way they say.
  15. The problem with old school timers is that a power cut throws them out of kilter. In a country with load-shedding like SA, this makes them almost useless. I believe Geyserwise overcomes this problem probably with an internal battery to maintain its clock and so it is a great improvement. However, there is a recent innovation : An astronomical timer is a new type of timer also with a battery reserve that you set your longitude and latitude and date. From a database it then knows all sorts of astronomical info. These can be had on aliexpress for relatively cheap. AF
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