Rick C

Hi guys, Has anyone tried to connect ground to neutral on Aliexpress-type inverters? (e.g. Easun-POWLAND, floating neutral-2 phases) They´re just inverters, with no connection to grid at all. I am thinking of connecting using a manual switch when a blackout occurs, supplying the loads of the house, completely disconnected from the grid. But, neutral is connected to the ground downstream. I have another instalation using a Voltronic-type and no problem at all w bonding NG, but I´m not sure if the cheaper inverters could do that. Thanks in advance

Thank you both for your answer. I don’t want to connect the wiring intentionally changed. What happens is that I am going to use the inverter only as a back up, and in the AC input (only for charging batteries if needed) I was thinking of connecting it using a 16A plug to a socket. And using plugs, sometimes we don’t care about polarities, I thought that there could be no problems. thanks again for the help

Hi everyone, Just a little question. Does it matter if I change the order in AC input wiring (L instead of N) in axpert inverters?. Thanks in advance.

Actually, nominal sum of the arrays power is 5.8 kw, but because of the different facing of them, the (planned) distribution is ideal to my needs and using of energy. The west array sometimes reaches 3.2 KW @3 pm (almost 40A), but the little north facing array (3s1p, mppt nr 3) begins to fail in the morning, when the amperage and heat are not quite high. I think it was a mistake to buy this inverter, (I bought it 2 years ago, having in mind to increase the panels in the future). But, I'm in this boat , so I have to sail as best as possible. I´m thinking in Growatt Hybrid SPH for the next years, The only thing that makes me feel in doubt is the limited amperage of the 2 mppts (just 12A). That forces to put the panels all in series, with the risk of affecting all the production because of little shadows. Thanks again for the help.

All my panels are 60 cells(voc 39v), so 3 in series are fine. 2 are insufficient and 4 will burn the scc, because of high voltage.

Hello again. As I wrote in a previous entry, I have a Voltonic tri (3 mppts). I have 3s2p facing east 3s1p facing north and 3s4p facing west. As you can see, all in trios. I have noticed that the inverter can’t handle well the three mppts working together. Sometimes (more often last days) the north array (mppt nr 3) disconnects and goes to 0, and don’t connect until the day after in the morning. The thing is: Can I connect the north facing array in pararell to the east facing array (3s2p + 3s1p = 3s3p)?? the North one gets some shadows in the morning... Can it affect the performance of east facing, even though they are connected in paralell? thanks again.

Coulomb thank you very much for your help. I agree with you. It is not recommended to downgrade the firmware. Besides, in the Australian forum they say that 75.31 patch is only for models under 1.0 PF (Mine is 1.0 PF). Can i get some help if I send a mil to Voltronic? Or in your experience, they never respond?

The 56.4 is got from the inverter, and also i used an external multimeter... Same volts. The setting 2 is @ 30A (250AH battery bank. Only Solar charging OSO Mode). The Batteries are Ultracell, I dont know the maximum (I couldn´t find it) , but I've heard that a charging at 0,1C es safe. Actually when I see 56.4 for hours and hours, the charging current is between 3A and 6 A.

Sounds creepy! I checked how the voltages vary and, even with high loads, the voltages sags very little. (51V-52V)and just for little seconds while the panels supply power to the load (Because I have 21 panels that previously to this high load were working at minimum capacity because the battery is already full ). The battery wiring is very thick, actually. So, no problem with voltage dropping. What I can do? Since I can't change that algorithm, should I buy one or more external MPPTs? and leave the Voltronic just as an inverter? This one has 3 MPPTs that would be completely useless! Or leave the smallest solar string connected to the Voltronic in order to automatically go to the grid at night? In this case, two MPPTs would be unuseful! The fact that it can damage the batteries is not funny to me or anyone. I enlarged the solar field to produce more energy and apparently I am in trouble !!

Hi all, I have a 5KW Voltronic Tri inverter. I was reading in the forum about a charging issue , and my problem is quite different from the one reported a while ago regarding the charging algorithm. I recently bought four 12V 250AH Ultracell Gel batteries (250AH @ 48V). I noticed that the battery voltage reading spends most of the day at 56.4V. I have 21 275W panels in 3 orientations: 6 facing east, 3 facing north and 12 facing west. All of them in 3-series (37.5 x 3 , 112 Voc app) We intentionally oversized the solar for my daily loads , it was designed especially for winter time and also to avoid deep discharges to the batteries. (I live in Chile, there is a lot of sun here) I use the only solar (OSO) parameter, but very rarely it reaches the float voltage of 54V, (Only when my house is alone and there is no great variation in the loads during the day) But, when I am at home connecting and disconnecting loads it is almost always at 56.4 V. They also get float stage when I switch to AC charging at night , and the AC charger puts some amps on battery and reaches float in a few minutes at 54V, and stays very pacefully at 54V until the next morning. My questions are 2 : 1) Could the batteries be damaged by the BULK voltage all day? 2) What is the logic of this wierd algorithm and can it be modified? As additional information the firmwares are 76.10 for mains 1.02 for SCC (the same for 3 MPPTS). (I suspect the problem is here) Thanks in advance. This is a really great forum!

Great test, plonkster! Did you prove that with a drill o and inductive load? Today, the electrician came and the conclusion was very similar. A voltage drop occurs followed by a recovery. The inverter (s) is (are) acts with a delay when a sudden load come in. But, we had some improvement adding an additional 4 MM2 wire from the inverter to mains. I mean, cabling affects flickering a bit, but it's not the most important thing. Could that 15V drop affect some devices in the long run? I dont know, but thats my main concern. I can live with slight flickering, or even I could install and additional small inverter just for lights. Thank you all guys.

Hi again, Next week an electrician will come to see the inverter and the installation. Also, today I made a couple of measurements that may be interesting. Using a multimeter in battery mode, I verified that the installation has no floating neutral. The phase at 230V and the neutral less than 1V, . Probably, the inverter makes the internal bonding. I turned on the washing machine and first using the utility, the voltage varied very little. Instead, in battery mode the voltage had variations of almost 8 volts. Probably more, because the multimeter is a cheap and digital one, not a pro. Incandescent bulbs have no capacitors and things like that. Thats the reason why they are more sensitive to flicker Well, I found out why the lights flicker, but I don't know why the voltage varies. I let you know what's next.

Finally, I will call an electrician to solve it. I will let you know then. Thanks you all for the help. This forum is amazing. Rick C

All the lights, and lamps connected to the plugs. In the incandescent bulbs the flickering is really noticeable( I only have four, the rest are leds or tubes). Lights are in an independent circuit in the switch box, not in the washing machine one . Nop In that case, safety switches would enter in action. Both them

Yep, but the thing is how it affects the speed of the inverter to react to the sudden loads, not the ampacity of the wire itself. Obviously the speed of the grid is huuuuge and always available. But in the inverter is limited. 4 mm2 wires could affect how fast it reacts? 10 mm2 could improve the situation? Thanks @The Terrible Triplet , A second little Inverter is a good solution, not cheap at all, but a solution.

Plonkster, That´s the point. The installation was made with 4mm2 wires from inverter to mains, I think they should be thicker, but I'm not sure if that affects how fast the voltage regulation from the inverter occurs. The ticker the wire (or the closer the inverter to mains) the faster the regulation? ==> final solution? But so far, nobody has written about the flickering, but I think I'm not the one with flickering issues. (Remember, I had to change the inverter, but for other reason: The problem persists). I´m going to use a voltimeter. And again... Could those voltage variations affect sensitive devices???

Plonkster, You have describe the problem perfectly, good example about the hairdryer. Also, parameter 4 is SDS I can´t believe that a 5KW inverter could not properly manage 300W inductive loads. As additional information, when the pool pump starts (3/4 hp), it´s just one flicker, after that there´s not problem at all. But the most annoying problem is the flickering when the washing machine is running, because it starts/stops/reverse running all the time. Thanks all for your opinions. But so far, I still have doubts. 1.) The thin 4mm2 gauge 20m lenght wire in the AC to mains could be guilty or not? 2.) If the inverter is connected as seen in the manual, what could be the confusion about neutral/earth? The neutral wire and earth wire are both connected to the same kind of wires in the switch box (mains).

Solarwind, As I can see, every wire is properly connected , I mean, the blue and the green-yellow one (Neutral and Earth) as indicated in the manual. The inverter is conected to the grid in the same way. How a neutral could be earthed not properly at the supply? Excuse me, I'm not an electrician, just a humble solar user. Plonkster, I was thinking to install an additional little inverter just for the lights and some help charging using the grid when voltage drops under 50V, avoiding excessive draining from batteries (40 A or more) I think is a good idea for combine solar and grid at the same time. But actually, my concern is to avoid damage in some sensitive appliances (boiler, computers , etc) with those fluctuations in the current. Thanks

Hi OomD, In my case, the parameters are 49 and 54. 50V is too high given the size of my battery bank (250 Ah at 48V). As a piece of advice, to monitoring my installation remotely, I use watchpower in an Intel Compute Stick in Windows (Also in the beggining I used an old laptop), and connected to internet via Anydesk. I can manage any parameter from my Iphone, Ipad or any computer. Regards,

Thanks Chris, I suspected (and prayed for) that the problem was that. Does anybody have an installation with so long cabling from inverter to AC switch box? I think in almost all cases, they're very close. But, I never read anything about AC wiring. Everybody was worry about DC wiring and losses. Rick C

Hi all, I´m a newbie in solar, and so far, I'm very happy with that, but the only one problem that I have is an annoying flickering in the lights (leds , but the incandescent bulbs also) when the system is working on battery mode and an inductive load starts. Especially, the washing machine (300W, and probably 3000W surge) and its permanent start-stop. Hair dryer also affects badly. That doesn´t happen on Line Mode. I have the Axpert plus tri 5KW, firmware 76.1 250 AH in 48V, and 3000 W on panels. 1. Could that change in current/voltage/frecuency affect the rest of appliances of the house, like the computers, leds or another sensitive devices? 2. Does anyone have the same flickering problem with those inverters? I replaced the inverter for a new one and the problem persists. Additional information. - The batteries are connected to the inverter using 21 mm2 gauge Wire, and the connections are tight enough. The flickering occurs no matter if there´s plenty solar power or is draining a lot of power from batteries. - The distance from inverter to AC switchbox is near 20 m, and the wire is 4 mm2 gauge. Possible answers, - The 4 mm2 for 20m could affect the capacity of the inverter in react to these sudden loads. (can serve that load, but not fast enough). The solution is replace them for thicker wires (10 mm2) - Worst case scenario: Axpert can't manage inductive loads very well, and I have to buy another small inverter for the lights and pray for the instabilities in current won´t affect the appliances connected to the load. I would appreciate any help/experience. Thanks in advice