KLEVA

Wait... Wait... I am misreading the diagram? That doesn't look right. What is your Grid feed? 3 Phase or Single Phase??? Back to the actual OP question: If you reconnect your other two phases back to Mains, and then only use your system on a single phase (backup only, not grid feed!), then you will be ok. But that diagram (by joining the poles together), is wrong without any other context... 1. Please don't allow feedback to Grid on only one phase! - This will give you more headaches and possibly smoke than you need in a 3 phase setup! 2. You need a decent electrical guy to advise you on the feedback and phases, and a correct neutral point. Stuff can get easily out of whack when you isolate a phase without comoning the neutral and earths correctly. It seems simple, but if done slightly incorrectly you will have floating voltages as high as 110V AC at points. Your current setup negates most of that by either being isolated or common across phases. 3. Please don't wire this as your diagram suggests, rather replace your 3P breaker with the correct single breakers on each single phase, although it may be simple to you, any electrical bloke (especially government or inexperienced) could easily misunderstand the wiring. (Note: this is just discussing what you proposed above) 4. If you are prepared (which it seem you are from your responses), get a damn good Victron installer to work it all out (again you seem to like the Victron stuff which is awesome just pricey). I am a qualified electrician who dables in Solar quite deeply in my private capacity, but I still think that any 3 phase solution has to be evaluated properly. There is too much risk in making a mistake. 5. 3 Phase brings an entire set of challenges vs Single phase. Although we tend to treat it the same (each phase is a single phase, neh?). If you miss the common Neutral and Earth between these phases by bad isolation/commoning when trying to split up a phase you are risking your home possibly going up in flames if done wrong! (Yes, this is a horror story and not really likely, but I have seen far too many bad isolations go south enough to cause fiery ends). If there is a shorter route, no matter how improbable, Electrons/Electricity will find it!.. Now that I have put the fear of a flame ridden death into you... What you are suggesting is a great solution. Just get it double checked (especially if you think you are going to do it yourself). It is worth the call out to both a high end electrician and a qualified Solar installer to confirm your calculations. You are working with 3 Phase here, and even decent home DIY and qualified electricians make mistakes... It is worth it to double check that there can be absolutely no feedback or isolation that creates a dangerous voltage/current situation.

If just for UPS (without Solar attached - but can add Solar later...): I have to recommend the Mecer 1400 that come complete with 2 batteries, or better systems for your specific environment and request - Damn, even Makro supply. My office ignored my suggestions of a proper system with solar for 8 laptops, 1 server, telephone system, router and 1 printer that would have run them about 20k min (without solar) and decided to just go for a Mecer solution powering 1 laptop, no printer, telephone system and router. Paid R8.3k from Makro and a few extension leads on top. I have to admit that that the unit performs well - With that small load, we easily get 6+ hours. That said, it is not a decent install and although very impressed with the capabilities of the Mecer unit, it is still a UPS setup, so batteries are key. Decent quality and size batteries can make even a "crappy" invertor seem good and perform decently. That solution is definately not "top of the range" not is it the "best build" but it seems like it will cope with the needs requested in your post (although my suggestion is to only use 1 printer attached and advise them very carefully that it will be for emergency use only... Any printing will kill the available power). Now I wait for people to beat me up on the forum for recommending such a basic solution As an aside, I have assisted some acquaintances with an Oxygen generating unit that was on a Mecer 1400 with some decent 105Ah boat batteries - Lady can't survive without added Oxygen for more than 15 min - That unit has survived through many Eskom debacles and is still going strong after 3 years. I think they only have had to use Oxygen tanks once in that time. As a UPS unit/invertor they are very impressive, but they will not solve all your problems unless you understand the uses.

Hi Shakama (Please bear in mind that these are my opinions/thoughts - Not everyone one forum - we all have our own ideas, but are generally on similar pages) You seem to have a decent sized budget for a small system, but we have no idea of what your load is to be able to advise on mid-level products or proper high-end products. This is very important in any Solar company or even us attempting to advise. eg: if you have a 1Kw/hr load then your budget can easily cope, a 5Kw/hr load then you are barely going to survive. Low-level products can also do the job and require different maintenance/support/costs per year, blah blah. I think there is limited doubt on this forum that the correct Victron installation is almost always the best, but we all have to use what is available in our budgets. I personally don't have the kind of money or usage that justifies the expense. Panels: Renewsys are good, sometimes the locally produced ArtSolar products (from Pinetown, KZN) are just as sufficient for sometimes a portion of the money. Batteries: Depends on your maintenance and budget - Trojans are the best high performance and low budget Lead/Acid, but they need maintenance. Many of the forum users are using the new Pylontech Lithium type which need far less maintenance and out-perform Lead/Acid - but at a cost premium. I understand the FreedomWon is similar to the PylonTech, but I don't know all the technical differences. As per my "Lessons Learned" blog posts on this forum - Batteries are almost the most important part of your installation, go cheap and nasty and you risk losing your home! Inverter: This is very subjective on the forum, and depends entirely on load and available funds. As mentioned above, I think MOST here would agree that a correctly installed Victron system for off-grid is the pinnacle... But that isn't always practical when it comes to money/setup/control/blah,blah... I can only suggest that you: Don't get an inverter that you will always run at near max, or constantly trip (ie: don't use a 3Kw inverter when your loads reach >3Kw more that 1 per week - even if it says it can cope!) An Inverter is actually the simplist part of your install to change. It might be pricey in your mind, but if you have the right batteries and panels, then you can actually start smaller. A decent inverter can deal with a lot of panels/power, even if it can't use it all, and as long as you keep your batteries at the right level then it doesn't really matter if you have too many batteries (my opinion). Regulations: (My personal opinion begins with a "F" word)... If there is ANY chance that you may need to connect this to the grid, even as an off-line/UPS type system, then familiarise yourself with the rules and products allowed. If you are always going to stay completely off-grid, then only concern yourself with standard electrical codes for normal installation - SANS10142 & SANS10142 Part 1 (or any subsequent amendments that I might not be aware of). Most of these are logical, and you probably already comply. For example: I run 4+ seperate solar installs at home, 1 for the basic house 220V AC, 1 for house 12V systems, 1 for Electric Fence and Gate, 1 for my permanent powered 4x4... Also have 1 for seperate charging system and temp inverter for emergencies. They all have different use cases - I use basic inverters and batteries for most (off the shelf Ellies & 2 chinese cheapie inverters), but for my permanent stuff, like the house, I have used decent products as best I can - I don't want it to fail and be fixed at the least opportune moments. I don't think anyone's install is perfect, we just try get closer and closer and closer each time. Any installer that will make a promise that your install will 100% solve your problem is lying, and that even goes for the installers here on this forum - They would never make that promise. So, this doesn't actually answer your question completely, but if you give us a bit more details (especially about your load requirement), then we can possibly advise a little better. Good luck and feel free to ask, that is what this forum is about.

In KZN we have a local Scrap Dealer who will collect (saves the cost of transport & labour), but it is at R6/kg - Still, managed to get some weekend party money for 140kg worth of even melted batteries and a few 7Ah from fences and gate motors. Taking them to a scrap dealer might get you R7.50 at the moment. Anything better will be for drained & cleaned lead, where they don't have to worry about the removal of the Sulphuric Acid and maybe even no casings. Deltec 100Ah are about 20kg each (up to about 25), so even at R6/kg... 60batts x 20kg x R6 = R7200. Don't accept anything less!

Supplier? I battle in KZN to find DC breakers, hence my AC backups when I travel.

1kW of lights? - if those are LED's, then which Province are you lighting up?😆 A good 2-3kW UPS with extra batteries can handle that if just UPS needed. Depends on the time needed and whether they all might kick in at once. The absolute cheapest option is to go for the Mecer type invertor (1400W or better) that you can buy with an extra battery box. I use one at my office and it works brilliantly (purchased at Makro with decent batteries for around R8k, far too much but not my call)... Will do either your lights or fridges for possibly 3-4 hours (so 2 of them needed) If you really want to be covered 99%+, then you need to get proper kit, but this comes at a price. An Axpert 5kVA hybrid type (or equivalent) is designed for Solar Panels addition, but works very well even as a UPS and can handle quite a large load. The negative is that you have to give it 48VDC in batteries. It makes a very good UPS and for the most part often comes in cheaper than good quality 5kVA UPS, and later you can supplement some solar panels. Decent enough entry to the Solar world. Note: can also look at the 24VDC 2-3kW setup, but then the costing doesn't make sense in my mind (personal opinion) If money is not an issue, then do not even play around... Go for the Victron stuff (on this forum it is the Blue Wave) and get it specced properly by a decent installer. That stuff almost never breaks and a good installer will also give you decent advice about batteries and maintenance. It will cost you a bit more than a few pennies, but it genuinely is the best product around in the SA market (honestly, I can't even afford it).

My rule of emergency thumb only works with good quality AC breakers (like Hager): (Note this is a very basic rule of thumb for small installs like 12V or 24V home/caravan) If it doesn't specifically have a DC rating then I go 1/2 to 1/8 x the size of the AC Current (lower the better). I use the following rough calc when I can't get hold of a DC breaker, especially when traveling: * 220VAC 10A breaker roughly can do max 12VDC 5A or 24VDC 2A * 220VAC 20A breaker roughly can do max 12VDC 10A or 24VDC 5A * 220VAC 63A breaker roughly can do max 12VDC 22A or 24VDC 12A Anything bigger then don't push it, I normally use this as a temporary fix for a month or 2 max, so it definitely doesn't get close to the multiple cycles of the switch so I cannot attest to lifespan. You also have to understand that a AC breaker will trip at MUCH lower DC current than AC. My experience has been at about 1/4 of the current. But more importantly will trip slower! ie: on AC an AC breaker will trip within milliseconds of exceeding current... An AC breaker on DC could run for nearly 2-3 seconds before tripping on DC current - so it is possibly hazardous, especially fire. As mentioned above - they have completely different requirements. Even though it still hurts paying the huge costs of a DC breaker, it is the right thing to use.

Hi, bit late to this topic, and I am only saying what I did with the Axpert when I had it running... On the output side of the Axpert (and after the manual changeover when I bypassed the Axpert completely), I bonded the Earth and Neutral. My main reason for this was that I was getting tired of getting zapped by my computer equipment and my CCTV cabinet! After reading a post on this or another forum (I cannot remember where), I risked it and gave it a try. There are probably many reasons above on how you should do it differently than I did, but I kept that Neutral-Earth bond after the output of the Axpert for over 2 years without issue. My Axpert only destroyed itself thanks to a 500V+ surge from municipal or storm that got passed my input protector (it was more smoke than the Axpert when it blew up). My internal UPS's would trip over for about 20s despite the short switchover of the Axpert when I had this configuration (removing the bridge stopped this, but zapping me was not a fun situation - and it threw out certain network cards). I was ok with the 20s tripping of the internal UPS's. Please note: Millage may vary - This is just my input, wrong or right.

Never mind the battery - Where did you get the kettle? I have only managed to find as low as 1200W, so would really like to find a 900W or lower (especially for my camping invertor that SH!T$ itself at 800W or more).😄

Hi Ryno How are your panels connected? With 6 you can have various combos, but for the Axpert with those panels it would normally be a 3+3. It is the Voltage you need to be looking at first. If the Voltage from your Panels is too low, then the Axpert doesn't kick in, if it's too high(eg: all 6 panels in series) then it blocks the Panel input. Axperts work nicely in about a 90VDC to 120VDC range (only my experience, others may differ) Also, bear in mind that an Axpert is a Hybrid type invertor. Based on your settings, it might just be that it is operating in a UPS type mode, where the solar panels are only keeping the batteries charged, in which case you can feed it the maximum power (not technically correct, just a similie), but it will only use and show enough to keep the batteries charged.

One of my servers (just a file sharing machine now) is still NT 4 Server, and I still have the original disks Also have Windows 3.11 on 1.44 Floppies/Stiffy in my cupboard - Still Sealed original Still feel old, my first PC/Programming was on a ZX80, plugged into TV and with 1kb expansion box

@nick9 - Referring to your original question - I have done similar myself on almost all my UPS's at home, but it's the charger that's built into the UPS that is the issue. Most home/small UPS are 12V or 24V (usually 24) with two tiny 7Ah or less batteries. My own logic, with only experience and history of failures, is NEVER go more than double the built in Ah, and only with a decent quality UPS. So, for example, I have a 2kVA ups that came with 7Ah batteries, which lasted less than 10 Minutes under near full load. Replaced the batteries with 14Ah and my time has jumped to 25min (mainly because the Voltage detection of the UPS can't kick in as quickly). I have tried on another UPS to go to 30Ah batteries, but they cannot recharge properly and eventually a circuit in the UPS died and popped the whole thing after a week. If you are going to do it, only go double the internal batteries, and on a decent UPS. the cheapies/chinese stuff just can't handle the charge current. Another alternative, which is only heresay since I haven't done myself - Get a seperate charger for the batteries, and then break or use a diode to prevent the UPS from trying to charge the batteries. Then apparently you can use huge batteries. Again, this is heresay from someone I know, but I have never seen their setup (or needed to try, since I have full house solar now).

@AnthonyThe 4KW rating of the Axpert only indicates it's capability, not what he is using at any one time.

See the ammended links, don't forget 2 panels rather than 1 would probably be ness to get the voltage at smaller watts

I would avoid that kind of generic charger - thats the same as you can buy at a Midas or similar - Absolutely no control or protection - these chargers are definately not for permanent use - they have limited or NO logic. I like PJJ solution, but would prefer to throw in the forum store. We know the people. But the products/thoughts are the same, and we support our own?... pricey, but obviously the high quality... and supported... https://powerforum-store.co.za/collections/controllers/products/victron-bluesolar-pwm-light-12-24v-10a https://powerforum-store.co.za/collections/solar-panels/products/enersol-50-watts Please remember the 24V spec - You need 28V for that controller in a 24V system so 2 smaller panels would work just as well to keep those batteries charged sufficiently https://powerforum-store.co.za/collections/solar-panels/products/enersol-20-watts

@PaulF007 - Sorry, lot's of options and confusions in my posts, my head sometimes thinks about 20steps faster than I type - My simplest answer now considering your question and the idea to keep it as cheap as possible is as follows: Get a cheap solar charger (almost all can do 24V, just read the specs) Either connect the Solar charger to small low wattage panels (my preference), or feed the controller with "fake" solar power at 18-32V (dependant on the controller above specs, or whatever basic transformer you can find) The solar charger (PWM) will keep the transformer or the solar panels from overcharging/damaging, and will keep the costs as low as I can think to make them That should solve your issue keeping the batteries charged - It's not fool proof, but might be cheaper than the 24V battery charger.

@plonkster - Apologies - I didn't mean the chargers in series, I (in my head) was reffering to the batteries in series... Although, series charger might work as long as it is isolated properly... Just need to test the charger and make sure it doesn't pull to ground/negative... It would have to give a full 24V without making sparks, so apologies if thats what it seemed like I was suggesting, it's a big risk of sparks and earth tripping on cheapie chargers.

Another Odd PS and maybe an option to consider: A cheapie Solar Charger can usually handle both 12 & 24 V systems - Maybe consider a cheapie Solar charger (R800 or less) and basic solar panel to keep charge - It's what I do in my van, then NO Eskom/Municipality. Still gonna be a manual system, but then you at least not paying Eskom/Municipality to keep them charged?

PS: And keep a spare also on charge if going manual - nothing you can do late at night or a weekend when no-one open, if a battery is poked... I have about 4 old car batteries around that I manually charge up about 3 times per year, weren't good enough for the cars they where in, but still operational and can deliver about 40A starter current if needed. Use these crappies to even help out when cars have been standing too long.

Wait... Do a cost analysis... The only way I can see this working (properly) with 2 seperate chargers connected in series to a 24V setup (like your generator) is that you will need to have some kind of monitoring device and a battery balancer? Cost of a battery balancer + cost of a monitoring device like a BMV702 (you want to watch the midpoint in case a single cell fails in one of the batteries), just seems to hugely outweigh the cost of a 24V charger/monitor... There are right ways & cheapie ways - if staying cheapie, then stick with the 2 12V chargers and monitor yourself once a month (on a maintenance schedule) - Its not fool proof, but will limit your risk. Right way is a decent 24v charger, a battery balancer, and something that will monitor the midpoint in case a cell fails or voltage falls below what you need to start gen. Manual monitoring will work, but not if it's critical to your environment. Do you take the risk of having to setup/purchase a new battery when offline? Mine is only a 12V starter, but I have a 48V bank nearby to jumpstart manually if ness, and I also have 2 spare batteries continuously charged, so I can lug into place if needed... Different solution to the issue, but extremely manual and frustrating when I need to use. So not a valid solution to your question.

@Chris Hobson - Maybe Sitelock has the right idea @Kalla - With the right amount of Capital investment, I will even guarantee a Eskom saving, it's just whether that saving warrants the capital cost. eg: pay me R14M and I will GUARANTEE that you wont have to pay ESKOM a cent for the NEXT 5 years. Just a joke, but underlines the point. My costs will never recover the price I pay the municipality, but I did it for different reasons. Saving must mean a saving, Solar electricity is difficult to get you to a saving point, so analyse the options carefully. The advantage of having power when ESKOM is offline must also be considered.

We work on 50Hz here, but even though I live in a semi-decent power area, I have had to allow my Invertors over the years to accept at least a 2Hz offset, and I personally don't think that anything other than extremely sensitive devices are outside a 4Hz offset. My internal SineWave UPS for my computer systems (which I cannot control their settings) do at least once per week switch and scream at me for a few seconds until the Hz comes back into range, but my new house invertor also assists with that. When it comes to the voltage though, its a lot more tricky, since you are usually feeding more sensitive devices. If your base grid is supposed to be 220VAC, then try not to let your invertor supply less/more than about a 15V difference. Since I have other UPS systems on my sensitive feeds, I do allow my Invertor to do about a 30VAC difference, but remember that our official rate is 220-240VAC. Since 99.8% (my guess) of appliances are normally the same in the rest of the world, then non-sensitive items like stove, kettle,water heater will be fine down to 195VAC (even less, but not really supported). Sensitive items like computers, cell chargers, etc, shouldn't really go below 215VAC, but most will happilly still work properly at 205-210VAC. It really depends on the device. If you get these fluctuations very quickly (like over a few seconds/millseconds), then you will have a problem with devices that are more sensitive and breakages could occur, then you need to look at surge protectors and probably more complicated protection. But if your day starts at 220VAC, and slowly goes down to 190VAC over 3-4 hours, and then back up to 245VAC (watch the highs over 240, they aren't as forgiving) in the next 5-10 hours or so (ie: extremely gradual movements) then you are probably ok. I worked in Nigeria where we only had bad Generator power for only 1/2 the day and with a decent surge protector we had no major issues.

A yes, the Commodore 64 (aka plonkster) has given you a good person to chat too Welcome Kalla, Having open land space/farm means that you can have a HUGE solar array, so the generated power itself is not the problem (obviously as long as you prepared to buy all the panels), it's how to store and deliver it to the end points. Chris will definately help with the maintenance side, since I am sure the panels themselves will need regular cleaning in the Karoo to get the best. Now, admittedly everything will depend on your budget (initial capital). You can go for the option of keeping the houses seperate, and distance apart will come into play when doing the calculation, but that huge 15kW load that you have initially identified might need a seperate solution if you need to keep the costs down. Solving a one off load is easier for us to assist with because we can ask specific questions about that load. For the purposes of my further comments/questions, I am going to assume this is the ONLY load you are trying to fix (the 15kW irrigation motor - Ignoring the houses for now) - And please, these might seem stupid questions, but I am in IT, not farming: single/three phase? Does it need to run 24/7? Does it matter if it doesn't run when there is no sun? further to the above question, if you do need to run it when there is no sun, then for how long? Do you have any wind/hydro options available to assist this huge load (for me as a nearly off-grid home-owner a 15kW draw is HUGE)? When discussing the DC (Battery/Solar/Etc) parts of the load, we need an idea of distances - AC voltages are less prone to any power drops. Ok, these are just my immediate questions, but there are bound to be a lot more. Because at a rough guess (based on your R12k figure), you are using about 7000kWh per month or about 240kWh/day - Do you know that that is mostly going to your pump, or do you have other heavy loads?

Not sure if I am misreading your intent or whether that is DOD% instead? Are you only pulling 20% of the power from your batteries 6 days per week? Or are you flatlining your bank one day and nearly flatlining your bank 6 days per week?

Welcome, you have bitten into the Magic Apple (Can't let Metro know, but that's exactly how I started - Lessons from mistakes)