Wetkit Posted November 21, 2013 Author Share Posted November 21, 2013 Ok, so installed the last 4 x 235W panels on Tuesday evening Was lucky as I finnished just before the rain hit. Wednesday was slightly overcast with rain, so decided to only run the pool pump. Still got around 11kwh for the day. Today, it is looking much better.... Currently running the pool pump and irrigation. Inertor is running at 41Amp so the system is keeping up!!! Quote Link to comment Share on other sites More sharing options...
Wetkit Posted November 27, 2013 Author Share Posted November 27, 2013 Well well, all I can say is that I am extremely impressed so far. Not any of my panels is truly facing north or at the correct angle, but it is not going too bad. Here is what I got the past week. I am extremely impressed with Yesterday, as it was overcast and rainy Mike and Pony 2 Quote Link to comment Share on other sites More sharing options...
Wetkit Posted January 9, 2014 Author Share Posted January 9, 2014 This is just to show what heat can do to PV panels. Last week when it was still summer here in CPT, I could just about get 2100W out of the panels. Look what happned today when the sun peeked out from the clouds Been thinking for some time now how to watercool the panels. Perhaps stick some water pipes to the back of each panel and circulate the pool water though them perhaps? Would heat the pool water and cool the panels Clint 1 Quote Link to comment Share on other sites More sharing options...
Wetkit Posted January 9, 2014 Author Share Posted January 9, 2014 So finally I think I have found the problem with my change-over contactors. Sometimes during the day, they would start "chattering". Basically one would come in, the other would also try comming in on the same time, and due the the electrical and mechanical interlock, they would start fighting each other That is the quickest way to destroy the contacts and/or your equipment. So I finally came up with this simple logic diagram below. I hope it could help some of you looking at doing something similar. MPPT - This is the load control relay on the MPPT controller. Basically if there is no sunshine (Day Night function), or my battries is low (Load Shed function), this contact will open. RA - This is a small control relay. Basically the function of this one is to enable the Eskom power if the MPPT or the Invertor fails for whatever reason. T1 - Delay-off timer. This will give the R2 contactor enough time to "fall out" before switching on R1 contactor. R1 & R2 - Mechanically interlocked contactors, rated 6kw. NO - Normally open. This is the condition of the contacts if the relay is NOT energised. NC - Normally closed. This is the condition of the contacts if the relay is NOT energised. So, if everything is 100%, the MPPT contact should be closed. If the invertor is fine, relay RA & T1 will be energised. Relay RA will drop out R2 contactor. 1 second later T1 would close its contact and energise R1. R1 contactor will then supply power to the Solar DB. If there is any issues with the solar system, invertor or MPPT, the logic is that everything will switch off. If Eskom power is present and ok, R2 contactor will be energised and supply power to the Solar DB. Quote Link to comment Share on other sites More sharing options...
Wetkit Posted January 15, 2014 Author Share Posted January 15, 2014 Ok, so during the past 2 weeks I have been seeing some funny stuff happening on my system, for no apparent reason. Would get home in the afternoon and find the MPPT controller still in sleep mode, WTF! So got on the line to Microcare to try and sort out the issue. First thought it might be some sort of software issue, but when I described the problem in detail, they said it could be an internal connection problem. So yeaterday after work I stripped the cover off and found the brown wire at the top of the PANEL breaker was never secured correctly. Basically the wire was never inserted correctly into the breaker terminal, so even if the terminal was tight, the wire was still loose Was a quick fix, but just frigging glad my house never burnt down due to this Quote Link to comment Share on other sites More sharing options...
leaves Posted January 15, 2014 Share Posted January 15, 2014 Hi There. I think Microcare is on the Forum. I know the technicians there come and check for posts some times. L Quote Link to comment Share on other sites More sharing options...
Emdav Posted January 15, 2014 Share Posted January 15, 2014 Howzit Wetkit, thanks for the link to this forum. Love your setup and the effort that has gone into it. Also impressed with your results. Your project is in another league compared to our "dabbling". Thanks D Quote Link to comment Share on other sites More sharing options...
Wetkit Posted January 24, 2014 Author Share Posted January 24, 2014 So I have this el-cheapo USB webcam that was laying around the house doing nothing. Why not use it? Every day I'm sitting at work wondering what is the Solar doing right now? Well, with some help from my friendly CTWUG guys, I got the little webcam going. So now I can sit anywhere in the world and see what is going on at home Try it and let me know what you think? http://wetkit.myddns.com/ It is nasty, so focus is not 100%, but you should get the idea. Cheers Quote Link to comment Share on other sites More sharing options...
BenDL Posted February 3, 2014 Share Posted February 3, 2014 Thanks for the detailed updates. I pretty much went through this same sequence of events last year, increasing battery capacity, then increasing the MMPT, etc. etc. Putting more & more money into trying to reach that elusive optimal point... Problem we have in SA is that we have lost confidence in the reliabilitu fo the grid & that is really where the hassle factor is introduced as we want to be "off the grid".Although this process is initially enjoyable, one becomes a bit of a power station manager. After a while the novelty wears off. During winter 2013 in my area the grid was quite reliable so you start questioning whether this is worth all the hassle & expense. My learning points were: Payback time on most of these systems is 6+ years, if you do a lot of work yourselves & buy wisely. (<R10/W) The sun doesn't shine 24x7 - Started mid Nov 2013 and the first full sunshine day was 1Jan2014. And even then you really get decent power from 10:00 to 15:00 in Gauteng. Battery capacity is the limitation. Adds expense & yet to see if batteries really will last 5 years. Grid-tied inverter is really the way to go if the grid is realiable - optimal use of the PV panels & use the grid as the battery. (Sure there are issues with City Power...) But munipalities are not very supportive of this - eats into their revenue stream, and all sorts of other excuses. Quote Link to comment Share on other sites More sharing options...
Wetkit Posted June 3, 2014 Author Share Posted June 3, 2014 Ok, just an update on this. Seems like my computer and the webcam did not like eachother, so unfortunately this does not work anymore. Regarding the power, currently the weather in CPT is pretty crappy, but the avg is still around the 5kwh per day, so very happy with that. Lowest I had to date was 2kwh in a day. Seems like my 2nd hand battries is also busy crapping out, damn Quote Link to comment Share on other sites More sharing options...
Wetkit Posted September 18, 2014 Author Share Posted September 18, 2014 Ok, just another update.... Started having weird issues again and could not really understand what was the cause. Issues was low power delivery and invertor doing weird stuff. 1st, had a look at the fused combiner, all ok. 2nd I had a look at all my internal cabling and connections, all ok. 3rd I had a look at extrenal cabling and connections, all ok. Right, so went back to the combiner and measured the voltage of each string seperately under load. Great, one string was way down on voltage So had to lift each solar panel out and inspect the rear connection box. This is what the 3rd panel looked like inside... You will see that the wire connection was never ever inserted correctly. Initially it worked fine, but I guess it started to arc causing a poor connection. Cleaned it up and re-did the connection. One week later and the system is still not performing as it should, damn!!! Well, it can only be the MPPT or the Invertor, so started with the MPPT, as it is easy to get to and open. Guess what, in January I found some loose connections on the internal cabling. This time the cabling was rock solid and not flexable as it should be. Basically this is caused when the copper wire overheats over a long time, either due to too small cabling for the current, or poor quality copper. Cut the old wiring out and replaced. Everything back to normal Quote Link to comment Share on other sites More sharing options...
Wetkit Posted January 13, 2015 Author Share Posted January 13, 2015 Ok, just an update on this one for now. System been running pretty stable now at around 17kwh per day. My main aim of keeping my monthly Eishkom consumption below 600 kwh is ok for summer, but in winter I struggle to get it below 1000kwh Right, so now due to all this Eksdom issues, I have been re-looking my complete system. At some stage I was looking to go Gridtied, but this is not worth it anymore due to return on investment and all the red tape involved to get such a system approved. So how do I utilize ALL my available solar power without too much hassle, AND still run some stuff while Eksdom is plodding along in the dark? Going Hybrid would have been the ideal, but I have not really found a unit that match what i would like to do, or the supplier that is importing the unit, knows nothing about it Anyway, for now I have settled on Bi-Directional. 1. Increase current PV capacity from 12 x 235W to 18 x 235W. Total then 4230W. 2. Keep current 60Amp MPPT. Output will be limited, but at least I will be getting max amps even if conditions is less than ideal. 3. Get current house wiring sorted and routed through garage to allow invertor connection. 4. I should be able to still use my old invertor, but once I have some spare cash again, install new invertor More to follow later.... Quote Link to comment Share on other sites More sharing options...
Mike Posted January 13, 2015 Share Posted January 13, 2015 wetkit come visit me sometime before you go bi directional. I am getting a hybrid on thursday, you can set off grid,grid tied, grid tied with backup. no red tape at all Quote Link to comment Share on other sites More sharing options...
Wetkit Posted January 16, 2015 Author Share Posted January 16, 2015 Hi Mike, please call me so I can come and have a look. Problem with these "grey" imports is proper english manuals and backup support. Another reason for the changes, is my pool pump. Just before I went on leave, the current 750w pump packed up. I go to the shop and see the cash diff between 1100w and 750w pump is very small, so best bang for buck is the larger pump, correct? Well, yes and no. Yes, for more bang for buck, but NO when running on solar. The extra 350w is an extra 8 Amps on DC. This is causing by invertor to overload when starting the bigger pool pump, when the 750w irrigation pump is already running. It is also draining the already weak battery bank way quicker. Quote Link to comment Share on other sites More sharing options...
Mike Posted January 16, 2015 Share Posted January 16, 2015 I will do so wetkit, there are so many variables on the hybrid. i am so sure it will work for you. Mine only arrived from Jhb today, so i will be changing over tomorrow. Even the municipal engineer today unlocked the streetbox for me so i can switch off totally, do my changes in peace and then switch back on. i will post pics when finished and will let you know.you can pop by anytime. Quote Link to comment Share on other sites More sharing options...
Willem Posted January 18, 2015 Share Posted January 18, 2015 Mike Can you post the type and model of your hybrid inverter? I need to make a few decisions in the coming weeks to get my system started.. Quote Link to comment Share on other sites More sharing options...
Wetkit Posted February 16, 2015 Author Share Posted February 16, 2015 Ok, so some time back I was planning to upgrade my existing solar system. The units Mike is selling do look great, but there was no news on the 5kva unit, so a 2nd hand MicroCare Bi-Directional invertor jumped at me. I got a great price on a nearly new unit, so I will be going that way. At least now I can remove my contactors and the installation will be looking way more profesional than what it currently does. I am still looking to get a qualified electrical guy to move all the required circuits from my main DB inside the house, to the garage, where I will be installing a new DB. For now I will be looking at dividing up my house circuits up into 4 parts: 1. Eskom powerd directly, no backup - Ovens and Air-conditioners. 2. UPS Powerd - This is directly from the Bi-Directional invertor. This will be for lights and my TV+computer stuff. 3. Bi-Directional Powerd but disconnected when Eskom fails - Geyser backup element, normal house plugs. 4. Bi-Directional Powerd but disconnected when Eskom fails + Solar power is low - Kitchen, Pool and Irrigation systems. Yes, it does look overly complicated, but this way I do not overload my solar system and still run most equipment from it as well. The other way is to run everything off the invertor, but then stand a good chance of overloading it, or running out of battery capacity during a power failure. This way I can also still run everything from my existing battery bank Quote Link to comment Share on other sites More sharing options...
Willem Posted February 16, 2015 Share Posted February 16, 2015 Wetkit Just for interest sake. With the bidirectional do you use a seperate solar battery charger then to charge the batt bank from the panels? So that the batt bank will kind of be the connection point between the solar panels and the inverter? Ho much will 'n good solar batt charger work out? Quote Link to comment Share on other sites More sharing options...
Wetkit Posted February 17, 2015 Author Share Posted February 17, 2015 Hi Willem, You have it 100% correct. I am still using my 60Amp Microcare unit and very happy with it. Price around the R8k mark. Another way could also be with a grid-tie invertor. The 230V from the grid-tie supply the bi-directional invertor with power to charge the battries. But this type of set-up can become extremely complex. See options 5 to 7 here... http://microcare.co.za/tech-support/microcare-wiring-options/ I am currently aiming for Option 2. Quote Link to comment Share on other sites More sharing options...
Wetkit Posted March 2, 2015 Author Share Posted March 2, 2015 Right, so I have been running the 5kw MicroCare invertor now for a week. In all honesty, I am a bit in 2 minds about this unit. The 48V to 220V conversion is about 80% effcient. My old invertor used to run untill 23:00 before the battries runs low, but the Microcare unit kills them around 20:00 The changeover between AC and battries is seamless now, so at least that is a plus point. Quote Link to comment Share on other sites More sharing options...
Mike Posted March 2, 2015 Share Posted March 2, 2015 does the microcare not draw 1.5amps per hour? maybe thats why you have less time, actually have this issue with a client Avie sold a microcare 36v system with 18 x 2v cells and it is in standby pulling 1.5a Quote Link to comment Share on other sites More sharing options...
Wetkit Posted March 9, 2015 Author Share Posted March 9, 2015 Ok, so I asked Company A to help me with the electrical canges and they said fine, no problem. Come the day of the install, nothing The boss comes back 3 days later to say there was a death in the family. Sorry to hear, but you could at lest have texted me!!! Anyway, found another company, RL Elektries. The guys came round and I showed what needed to be done. They sent me a quote and couple of days later the job was done!!! Eish, it was not cheap, but for me to do all of this by myself? Propably 10 years ago. Still waiting for their quote to get the rest of my house up to spec. Could be scary??? So now the 2 x stoves, 3 x Aircons, Solar Geyser and general house plugs is on Eksdom power. The rest is on Solar. I did have a bit of a hiccup with the microwave. Basically when the perculator, microwave and toaster is running at the same time, the invertor pukes and die. According to the manual and the invertor software, it should re-start automatically, but this does not happen So had to move all those device's back to Eksdom power. The DB is divided into 2 sections, Orange for normal power and blue for invertor power. The blue section is divided into 3 sections again. Section 1 is like pure UPS loads, like DSTV and lights. Sec 2 is like less important loads like dishwasher, pool pump, ect. These loads will be dropped automatically when Eksdom power is off. Sec 3 will still run via the invertor and battries with an eksdom power failure, but if solar power is low as well, these will also be dropped automatically via the MPPT. This is stuff like the fridge, freezer, garage doors, ect. The idea of all this is too use the least amount of Eksdom power during the day, still have the protection of the invertor for all my important equipment and also have reserve battery capacity to run during a power failure. The MPPT tells me now that I am using 20kwh per day now At least I can now play around with the circuits to get the right balance solar power, eksdom power and backup power. Quote Link to comment Share on other sites More sharing options...
Wetkit Posted March 27, 2015 Author Share Posted March 27, 2015 Right, so just an update for now... I have just recieved my CoC for the complete electrical system. What a mission that was!!! Stuff that was legal some years back is suddenly not legal anymore. Anyway, that's 100% sorted now, including a new and seperate earth for the solar panels. My old battries did take a bit of a knock now with the increased load. So, I did an extremely hard thing and installed a new battery bank. So, this is what the installation currently looks like. This is the 6V Trojan T-105 battries, rated at 225AH. This was all I could afford at this time. Idea is to buy another set in the near furture. Well now, guess what, I changed my mind yet again After running with this configuration for a week or so, I see that the battery bank is working way too hard. Even if I install another set of battries, I'm not 100% convinced that that will help. Increasing the PV capacity could also help, but then I need another MPPT. Well, so what is the solution??? My current solution is to sell my old battries, Invertor and MPPT. With those funds I hope to buy a Hybrid invertor. The plan is then to run the Hybrid as an UPS. Using all available solar power during the day while keeping the battries topped up. Battries will only be used when Eiskom power is out. My internal load shedding relay system is also working great and this will help not too drain the battries with unnessesary loads. Quote Link to comment Share on other sites More sharing options...
Mike Posted March 27, 2015 Share Posted March 27, 2015 I think you are on the right track, my hybrid when there is load shedding in the day uses zero from the batteries and only uses pv as source, with my small 205ah bank at night i run through loadshedding without knowing there is load shedding.I set mine to use pv first then eskom then batteries but you have so many variable to play with. once i upgrade my pv string i am going to try load first from pv then if insuffiicent battery and then if battery low to eskom, that way i will return much less or should i say they will not get so much from me for free.... Quote Link to comment Share on other sites More sharing options...
Mike Posted March 27, 2015 Share Posted March 27, 2015 What thickness cable are you using on your battery bank? 16mm multistrand or welding cable? Quote Link to comment Share on other sites More sharing options...
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