Modina

The only true Voltronic Axperts that I know for sure are RCT, Kodak & Mecer. I presume the following to be clones, but maybe there are some that may be genuine. Would be good if others could point those out. Must Phocos FiveStar Synapse SUN (ACDC) MCE FCS TheSunPays GRW Growcol Navasolar Top Solar Lalela Kingstar Sunmart Vito TechGeeks Ecom Light

It sounds as if you are not considering solar panels at the moment? Maybe you will never have panels because you might be prohibited from installing panels, or you might stay in a stack-simplex where you don't have your own roof, etc. However, if solar panels are on your list, or a possible future expansion, you need to consider the solar charger specifications. If you have a tiny roof or difficult orientation, an inverter with a low power/voltage MPPT might be OK. Otherwise select an inverter with a high power/voltage MPPT. I would consider one of the Kodak models. They are stocked by many suppliers, spare parts seem to be easily available and it is a true Voltronic, i.e. not a clone. You are correct with your battery charging reasoning. You might want a higher current charger if you ever were to consider adding a 2nd battery. Low voltage MPPTs - normally have Solar VOC = 145V High voltage MPPTs - normally have Solar VOC = 450V - there can be a slight variance between models and manufacturers

If your UPS runs from 36V then my suggestion will not work. It's a pity it uses such a voltage. If it was 12, 24 or48V you would have had more options. Your batteries now have 4x more capacity than the 7Ah and your UPS charger might battle to keep them charged. Axpert inverters can be considered as an off-line UPS. In UPS mode they are specified to switch over within 10mS. An online UPS like yours runs 24/7 from batteries/charger and thus doesn't need to switch over. Here is an example of a 1KW 12V Axpert inverter. https://www.takealot.com/five-star-1-2kva-1kw-pwm-12v-solar-hybrid-inverter/PLID92571048

Well that is a bit silly. Long term storage of Lithium batteries is recommended at 50% SOC. Nothing would be simpler than to discharge your battery to 50%. For instance, you can use a 12V 5W LED. Such an LED would draw a current I = P/V = 5/12 = 0.42 A. Assuming your 50Ah battery is fully charged you want to discharge it by 25Ah. So you need 25Ah / 0.42A = 59.5 hours. You could use other known 12V lamps such as an old 50W halogen, or some 12V car bulb and repeat the above calculation to figure out for how long to run the light of a particular wattage.. As to the rest of your problem, I am really confused. Does your UPS run from 12V? You have 3 lead acid batteries connected in parallel? Running two inverters in series is just plain silly. It seems you require a pure sine for your IT stuff and the Mecer is Modified Sine only. The best would be to get rid of both inverters and buy a 1KVA 12V Axpert inverter. They cost R4500 at takealot. Then sell your old inverters. The other thing you could consider is to use your Mecer as a battery charger only, and your sine-inverter as an inverter only. In this case you would get rid of your lead acid batteries and connect the Lithium instead. But this is really clunky. A 12V Axpert inverter is the better option. It would switch from grid to inverter in about 10mS which should be acceptable for your IT equipment.

I can't remember where I read it, but it was reported that the SA solar & alt energy market has the highest scam and fraudulent incidences of all sectors at the moment. And I am not surprised. There is still a severe shortage of hardware. For interest, I had a look at Google Earth pictures a few days ago, and even in affluent neighbourhoods, most roofs are still naked... People are desperate to get systems installed and are easy and soft targets. Loosing 2 or 3K is painful enough, but there have been a few Powerforum members that placed orders for inverters and lithium batteries for at least 40K+ which they lost. This is not small change. People need to make all possible checks. I expect that fraudsters will soon start operating under reputable company names to entrust clients.

@IgnatiusI don't care how good your installations are. I'm a engineer and I sometimes hate the marketing men who just waffle and often make more money than the manufacturer. But this is how the world works. Marketing makes or breaks a business. Without marketing most companies would not exist. Your company name is just plain silly. I am not going to pull any punches here. You obviously do not know the most basics of psychology. Your company name is the first contact to your potential client. With a badly chosen name, you will be the target of jokers and nobody with a brain will take you seriously. With a silly name, you will have to under-cut everyone to get any business. I already gave the example of a Pretoria company - Papnatbesproeing. The name will only attract rice and water-lily growers. The name triggers images of burst pipes, leaky valves and dripping taps in my mind (!) My advise is for you to see a marketer or at least someone with some sociology skills and language creativity and find a new business name. Yes, it will be painful to change it, but long term it will be worth it. Are you kidding me? Are you surprised??????? REALLY? Where the hell have you been the last three years? I have always considered myself reasonable knowledgeable about the world. But I was WRONG. Today it feels that I have been living under a rock for the last 30+ years. EVERYTHING is FAKE. Big-C has finally opened my eyes. Today I question EVERYTHING, trust NO-ONE. TV and MSM is only showing us a movie. Today I am a big fan of conspiracies - I am one of those mad people you are constantly warned about!

I like giving people options. MPPTs are not exactly cheap. The cheaper models might fit the bill for now, but will have too low current and voltage limits to be usable at some future stage, should your friend want to upgrade his system. Your friend could consider dropping the output voltage with a few diodes. Small diodes have a voltage drop of about 0.7V but high current diodes usually much more, typically 0.9 to 1.2V. Rather than buy separate diodes, I would use a bridge rectifier and use the + and - terminals that effectively has two diodes in series. For instance, two of these rectifiers https://www.communica.co.za/products/fb3504 would cost less than R 100 and provide about 4.0 ... 4.8V drop, depending on the current. You should mount these rectifiers on a small heatsink. For PWM chargers it is better to drop more voltage and stay away from the peak input voltage. The charger has anyway no ability to use the extra voltage headroom. Should one do this? I don't know. You will waste some available solar power. A PWM charger is anyway not very efficient. One will likely loose 25 to 35% overall. The elegant way is to use a MPPT, no doubt about it. Another option might be to sell the PWM inverter and replace it with a MPPT inverter. Your friend should first decide how many panels he wants to use and then choose a MPPT that can handle those panels. He might be very shocked how expensive a MPPT is if he goes for a system with more than 2 or maybe 4 panels. PS. Note that without a load, the voltage drop of diodes will be less than during high current loads.

Lesswatt ? What an idiot name. It reminds me of a Pretoria company calling itself Papnatbesproeing. 🙄 Buying from Lesswatt will leave a hole in your pocket with NoWatt.

A CT transformer has a current output. It is critically important to place the termination resistor at the inverter side. Your long cable will then be a low impedance current loop which will have excellent noise immunity. Because the circuit is low impedance, the stray capacitance that @P1000 mentioned will have no effect, especially not at the low mains frequency of 50Hz. If you where to place the termination resistor at the CT coil side, the picture would change completely. The termination resistor converts the current into a measurable voltage. Your cable would then carry a sense voltage with practically no current at all. It would be a high impedance circuit that would be very prone to noise pickup. Also, due to the high impedance, the stray capacitance could start to have an effect. I would stick my neck out and say that if you run as a current loop, your cable could be unshielded and it would be OK. However, I agree with @BritishRacingGreen to rather use a shielded cable and play it safe. It is important to connect the shield to ground. I agree that this should be done on one side only. You want the screen to only work electro-statically and want to prevent a current flowing through it. Simplistically, the screen will act as an aerial for radio-frequencies and short these to ground. The cables within this shield are then protected and not subjected to such radio waves. It is best to only use one twisted pair. The twist in the cable makes sure that the two wires are tightly bound and any noise that might get picked up does so equally in both wires. We refer to such noise as common mode noise that is easy for your system to ignore. If the two wires have a distance between each other, they can be seen as a loop, into which noise could couple differentially and add to the signal. Differential noise is problematic. PS. I presume that your inverter would have the termination resistor mounted on a PCB within the inverter itself. That is perfect. Then you do not need to worry about it.

... maybe a piece of that conrod slammed into said microwave.

I still don't know if this is an electro-mechanical or an electronic timer/clock. All electro-mechanical timers use the 50Hz mains. In the old days, all mains powered clocks where also using the 50Hz mains. These days many clocks are using 32Khz crystals with battery back up. So the rule is this, if the clock looses it's time during a power outage, it is not battery backed up and relies on 50Hz. @TaliaB nobody disputes your claim but what is in dispute is a 200% error. A genie can be out by 20% but if it runs 3x faster than designed for, you will likely pick up pieces of the conrod that slammed a hole through your engine block and spewed hot oil all over the place. You would also have run for cover before that engine disintegrated... What does a genie run at? I think 3000rpm ? Now imagine it doing 9000rpm.🙉🙈

@JustinSchoeman Yes correct. The overall load will have a poor power factor. It will look very much like any other device where DC rectification is performed without additional PF-correcting circuitry. The difference here being that a microwave is an extraordinary heavy load, while normally DC power supplies are seldom over 300W or so. I recently noticed that one can now buy "inverter" microwaves - at a hefty price. Perhaps I was asleep and have not noticed them before, or they are now new on the market. So obviously they chucked out the big and heavy 1.5KVA+ transformer and replaced it with a PF-corrected high-voltage SMPS. I wonder if an inverter can somehow drive a magnetron at less than full power. Currently magnetrons are driven bang-bang on-off, in the same way that cheap solar chargers, euphemistically referred to as PWM, work.

@JustinSchoemanNo, the load on the secondary of a microwave transformer is full-wave. A microwave has one diode and one capacitor, so it can easily be assumed that it is using a half-wave rectifier. However, the diode and capacitor are exchanged. The transformer feeds the capacitor, and the diode is connected thereafter. This acts as a voltage doubler and produces about 4000 to 4500VDC. Voltage doublers rely on both half-cycles to be able to work. I have no idea whatsoever what could cause a 3x clock speed. This microwave uses an electro-mechanical timer or an electronic clock? It isn't explicitly stated. I am not even 100% sure if the generator is to blame. I am asking myself if it might not be some peculiar earthing issue, but I can't put my finger onto anything specific.

Just because someone posts something on Youtube doesn't make it the gospel truth. A generator is a rotating machine and by definition will produce a sine wave. Yes, it has a finite output impedance and can be yanked around by a difficult load. This could indeed produce a non-uniform wave with more THD distortion. However there will be no switching noise from a genie and thus no high frequency harmonics. The waveform will still be rounded. The guy in the video above made one mistake. No load. An oscilloscope has a typical input impedance of 10 Megaohm. There is something called the wetting current. This is applicable to any form of electro-mechanical contact such as a switch or slip-ring. A slipring might look smooth and clean to you, but under a microscope it looks like a mountain range covered with dust, oil films, oxides, moisture and all sorts of other gung. The wetting current is the minimum current that needs to flow through such a contact to make a reliable connection. I am not surprised to see the noise on that scope. Different generators will have different slip-ring alloys, different finishing techniques applied, different brush loads, oxidation, etc. When I was still in the defence industry, I spend many, many hours in technical review meetings discussing the non-compliance of slip-rings in missile systems and our supplier spend 100s of hours experimenting with all imaginable variables to try and improve matters. @TimCam is right about the RPM -> frequency variations and also the RPM induced voltage variations that an AVR tries to regulate but often fails to do adequately. Diesel engines normally have much bigger flywheels due to the high compression and this would give a higher mechanical damping, improving the load regulation. There is no reason why they can't mount a bigger flywheel on a petrol genie, except that it adds cost and weight... so they don't bother. Run a genie at low loads or at constant loads. Failing to do so will give voltage fluctuations that can be problematic and damaging. The waveform distortion and even the frequency variations should not be a problem for most equipment.

I am renovating and intend fitting both 12VDC and 230VAC lights in various rooms. It has been pointed out a number of times here that AC and DC circuits are not allowed in the same conduit. So I will chase the walls open to fit a 2nd conduit. 🙄 My question is this: Is it allowable to run DC & AC into the same 2x4" wallbox and fit two switches on one bezel, one for AC and one for DC? Or do I need to fit two wallboxes, one for AC and one for DC?

Your solar panels are likely to contain 3x bypass diodes. Each diode will have a forward voltage of about 0.6V. This means that a shaded panel will have 1.8V drop across the three diodes. Let us assume that during hours of shade you are likely in the morning or late afternoon periods where your solar panels will anyway be down on power. Let us further assume that your panels will deliver 10A at this time. This means that the 3 bypass diodes will dissipate 1.8V x 10A = 18W of power. This power will be stolen from other panels. If you now connect a whole-panel bypass diode, you would only loose 1x 0.6V x 10A, i.e 6W. A power saving of 12W. The diodes are cheap, but you would need extra Y-connectors, cables and the schlep of installing this on your roof. All that effort to "gain" 12W is not worth it. The above assumes that the internal bypass diodes are all working OK. If just one of those diodes would be faulty, you could stand to loose a lot of power. You could test and replace individual diodes. This would be quite a mission because you will likely need to remove the panel. You could also measure the voltage drop across a shaded panel. If that voltage drop is less than 2V that means all diodes work. If the voltage drop is much higher you have a problem. THEN the easiest way to "repair", might be to fit a whole-panel (external) bypass diode. All this from a guy that doesn't even have solar panels.... 😄 If it was my system, I would wait for dusk and then disconnect the one or two panels that get the shade and use a small 9V or 12V battery with a suitable current limiting resistor (say 1Kohm) to connect over the panel while measuring the panel voltage with a multimeter. I would hope for a 1.5 to 2 volt reading.

I would be interested to hear of any positive and negative health consequences of load shedding and the use of inverters. Either personally experienced or anecdotal reports. For instance, your elderly mom might be staying in a retirement home or in a flat where the majority of people would not be able to afford inverters. 4 hours of load shedding should substantially reduce EMF, dirty electricity (high frequency switching noise), WiFi signals and even cell-tower radiation. So the old lady might have mentioned that she feels "better" during/after L/S. Most of us cannot perceive these various radiation effects, but there are certainly people that can. A tendency of getting headaches, migraines, fogginess, sleep deprivation, tinnitus and even blood glucose level changes could all be triggered by EMFs. You might just have never realised the link. You likely shrugged of your mom or dad for mentioning this, rolled your eyes and mumbled something about them being old and imagining things... Many of us have to deal with inverter fan noise or worse, some SunSynk owners hear 15KHz whistles. But it doesn't stop there. Inverters are exceptionally high current switching devices that can radiate EMFs via the mains and other cabling where this acts like a large aerial throughout the house. Yes, inverters have filters, but these are not brick-walls, they are attenuators. A lot of noise can still escape. So it is quite likely that some people that use inverters feel "worse" during load shedding. Not all inverters will be equally bad and wiring "errors" could have a major negative effect as well. I have been interested in this field for the last 10 years and have been reading the literature of EHS & MCS (Electromagnetic HyperSensitivity and Multiple Chemical Sensitivity) for quite a while. I have even invested in some (basic) test equipment for measuring RF, E & H-fields. It is a very controversial subject, as always, suppressed by big industry that wants you to think that all this is totally harmless. Some people in SA offer measurement services to quantify the severity of radiation but I am not aware of anyone (locally) offering mitigation advice and services. It is a complex field due to the many different forms of radiation, each requiring different techniques. It can also be very costly to mitigate EMFs. For people who don't know how debilitating EHS & MCS can be, I suggest reading this very short 2 page article about Kim Palmer: https://www.eiwellspring.org/stories/KimPalmer.htm

Oh that makes sense. I wasn't aware that you had solar panels on this inverter. If you find a cheaper lithium charger with at least 10A let me know... I am all ears. 😄

You didn't say what specific 12V 1KVA Axpert you have, but most of these have a max 20A AC charger. It seems you are already on that setting. The only way to boost charging would be to connect an external lithium battery charger and have both chargers run in parallel. All voltage settings would need to be matched for this. Lithium chargers are not that common and you would likely need to buy a Victor charger for 3K, such as these: https://www.sustainable.co.za/collections/battery-chargers/products/victron-blue-smart-ip65-12-10-10a-12v-battery-charger-with-dc-connector https://www.sustainable.co.za/collections/battery-chargers/products/victron-blue-smart-ip22-12-20-20a-12v-battery-charger BTW, adding an extra battery would most likely not help much, as your charging current seems to be the bottle-neck. Except if you are a night worker or night-owl, I find it odd that you run out of capacity at night. It sounds as if you have very powerful flood lights. Are they all LED? Can't you reduce the power rating of these? This might be the cheapest option.

I am sure the municipality will be very happy as well.... to be able to buy some electricity back at next to nothing rates, to then sell to the average Joe at the full rate. Selling electricity does make sense for large industrial sites such as manufacturers that might not operate on weekends and thus have Saturday & Sunday solar over production. But for everyone else, they can shove their misery few cents/ KWh where the sun ain't shining !!!! Especially with 1000s of rands worth of bi-directional meter costs and monthly levies. Boy, these guys are sick. 🤮

If I reply to someone's needs, I will consider the overall picture. A person with a flat on a bicycle will not be interested in a 3-phase compressor. @Scorp007 You can buy 50A and 100A battery chargers as well. Professional equipment that will most likely cost 25K and up. Those chargers you conveniently show with the manufacturer label cut-off are Victron products. The 12V 20A charger is about R 3000. You surely don't expect people that brought a 1000W modified sine wave inverter that is advertised at about 2K to buy a battery charger costing 3K, to be used on lead acid batteries. Jy is nou besig om die dam onder die eend uit te ruk. 🙈🙉🙊 Not everyone can afford to drive a Porsche. And then you get people WITH the money who would never agree to such extravagance either. I am not impressed with a car manufacturer that builds good cars costing 5 million. What impresses me is a manufacturer that can build a damn good car for 250K. THAT takes skill.

With a quick search I have found various suppliers that sell this Fivestar FS-1006 but nobody gives the specifications where one can see what the internal charger is capable off. So we are in complete darkness to it's operation. Just about all lead acid chargers are sold for occasional car battery charging, intended for slow and loooong charging cycles of typically 10 hours or longer. With our current rate of L/S this is obviously not practical. Also, these chargers are not designed for UPS-like charging that requires constant monitoring and re-enabling of the charge process. For a car battery application, the charger assumes the battery reaches a full charge and is then returned to normal operation. So these so-called intelligent chargers might, or might not, re-enable cyclic charging. In other words, charging might not be automatic and require user input. I.e. switching the charger off and then back on again. There are cheap battery management systems like this one https://www.robotics.org.za/XH-M602?search=battery charger but I regard them as completely useless. A device like this would switch the charger off at the START of stage 2, top-up charging, so the battery would never see a full charge. I think that over-charging is very unlikely in current SA. Let's assume you have a 100Ah battery which you discharge to 50% DOD. That means you need to replenish more than 50Ah (the battery has losses which get burned as heat, so you need to put more in than what you get out). Most chargers can do no more than 8 or 10A, so it would take about 7 hours to recharge. It is sad not to know anything about that internal inverter charger. One could measure the charge current but if it's more than 10A it would blow a multimeter's fuse as they are all maxed at 10A. Whatever that internal charger can do, with a 200Ah battery, things will get twice as slow. So I predict that you are more likely to severely undercharge your battery which would be a killer for a lead acid. There are really not any easy solutions for this. @Eurard mentioned this link: https://www.takealot.com/12v-10a-pulse-repair-lcd-battery-charger-for-car-motorcycle-agm-/PLID90409460 This is sold as a 10A charger but it is NOT 10A. I know, because I have one. This is a 6A charger. I think this manufacturer does make a 10A version, but it seems that those sold locally, or at least on Takealot, are all the 6A versions that are wrongly claimed to be 10A. Because these are quite cheap, you could consider trying one of and run it in PARALLEL with the inverter's internal charger. Especially if you are going to switch to a 200Ah battery. The Takealot charger actually displays the battery voltage and the charging current, so the voltage indicator could be used to oversee what is going on. You can even leave this charger connected to the battery but not power it from AC and then use it as a voltmeter. Note that the above mentioned charger has no AC input filter and produces switching noise that I can hear in my PC speakers whenever the unit is on. This happens as long as it is charging. Once fully charged it will display "FULL" and the noise stops. The unit also has a small fan, but it is not loud. The problem with all these cheap solutions is that they have never been designed for, or intended to be used on a semi-continues level. These systems are OK for a 5 day camping trip, but not everyday use. Also note that you cannot buy any battery charger that claims to be compatible with 20 to 100Ah but fails to specify the charging current. Such a marketing statement is totally useless. If a manufacturer cannot even specify the charging current of their device, the only place for such a product is inside the trash-bin.

I brought a 3KVA 24V Axpert clone and a Hubble AM-4 battery earlier this year for just over 27K. Then I needed a lot of extra hardware to integrate. This trolley has similar specs to my separate component system for just about the same money. The disadvantage of a trolley like this is that the inverter doesn't have a conventional form-factor. If my inverter was to pack up, I could easily exchange it with a multitude of other inverters. If your trolley packs up, it needs to be repaired and that could be a difficult and long process and in worse case, you might not find anyone to do the repair. The battery is also a question mark. I would like to know what battery they use. The choice of 24V lithium batteries is limited. They might even have put 2x 12V lithiums in that trolley and then "forgot" to install a battery balancer. This would be problematic. This trolley inverter has a low voltage MPPT which is quite acceptable. If you want to use solar panels in future, try to avoid inverters with only a PWM solar charger. There are some people that build trolleys from separate components, but they do not look as elegant, are likely to cost more, and do not have features such as the USB & 12VDC outputs. I would make sure that it has a single 24V battery or that a battery balancer is provided. Besides that, this looks like a neat and fair priced solution.

Here are my two worthless cents about this: 1. Grid-tie doesn't make sense to me in SA. 2. Grid-tie makes even less sense on small inverters such as this 3KVA. 3. Holliday homes are often standing empty for long stretches of time. I would certainly not put a lot of solar panels up on the roof. The likelihood of theft is enormous, especial in the current situation. 4. For the above reason, an inverter with a 145V MPPT should be sufficient. 5. 10K I regard as expensive. Especially on an unknown product. For instance, you can buy the Kodak OG3.24 at the Power Forum Store for R 9315, and they show plenty stock available. We know that Kodak is not a clone and although I didn't compare the specifications line-by-line, I would expect more or less compatible specs. The OG2.24 also uses a high voltage MPPT. But I will not stop you from buying a DNEA. We need people to be riskier with their money than what I am, and then report back. Only this way can we expand and grow and separate the Good from the Bad. 🙂 Who knows, maybe DNEA will become a household name in 3 years time.

Elektor magazine had a design competition in 1995 and the 1st prize went to a John Dakin who build a 30W wind-powered battery charger using a standard permanent magnet radiator fan motor and a 800mm wooden propeller. The project was claimed to have cost 20 Pounds (excluding the propeller). The electronics use cheap, easily available components and there is even a single-sided PCB layout. I attach the article below. Wind generator battery charger (Elektor).pdf