Hello. I am new here. I've figured this site has a lot of information regarding Voltronic products, so I decided to make a post regarding my question. I have the "Inverter Voltronic Axpert VMIII3000-24V". I am facing an issue with the inverter caping at 120v of solar input. My solar array system is much stronger. I heard it is a firmware issue. After I got the inverter, I haven't installed any firmware on it, but now I am planning of doing so. Can someone recommend any available firmware that I could download and install on the inverter? Thank you so much.

31 minutes ago, NoahAndArk said:

Can someone recommend any available firmware that I could download and install on the inverter?

Yes, but for technical reasons you have to tell us what present main firmware you have. That's the U1 (DSP) firmware version. You can find this from monitoring software, or from the front panel via the up or down buttons.

That's an unusual pattern on the front of the inverter; I've not seen it before. Hopefully it is a genuine Voltronic, or at least one that can be updated with Voltronic firmware.

Hey. Thanks for replying. I believe this is an updated model, although I am really unsure. I do not yet have an RS232 to usb adapter, so I am waiting for that to first arrive to plug into the system. I was thinking of using a USB drive to update the system, as I checked in the manual it seems possible. I bought this inverter from Spain, from a respectful company: https://suministrosdelsol.com/en/all-in-one-inverter-24v/840-inverter-voltronic-axpert-vmiii3000-24v.html

I can't yet verify the firmware which I have because I do not yet have the adapter, unfortunately. But, here are the two pictures I took, first shows the details of the inverter and the other shows the input voltage of my system which is stuck at 120v:

 

21 hours ago, NoahAndArk said:

I can't yet verify the firmware which I have because I do not yet have the adapter,

You should be able to see it by pressing the up or down buttons on the display until you see something like

U1

12

34

which in this example means main firmware version 12.34 .

Hello. Thank you so much for replying. I found the option you spoke of. Here is the picture:

I have changed the wiring of my solar array, and tightened the connections to the inverter/charger, and now I am getting over 200 volts, but 0 Amps. I don't understand what is wrong. I have 8x 32.4v 440w solar panels, connected in series (combined voltage). The charging is still slow despite inputting over 200 volts, very odd. I attached another picture, which shows the Amp input. I am actually getting error 15 now, despite having increased voltage input. 

 

Update. Still getting stuck on 120 volts. Still 0 A input on a sunny day. I spoke with the technician of the company, he said to check out the current using polymeter, which I don't have.

On 2024/12/16 at 5:38 PM, NoahAndArk said:

I am facing an issue with the inverter capping at 120v of solar input. My solar array system is much stronger. I heard it is a firmware issue.

Alas, I have no 47.xx in my collection of about 200 firmwares.

Does it always read exactly 120 V? I'm wondering if the measurement is faulty.

3 hours ago, NoahAndArk said:

I spoke with the technician of the company, he said to check out the current using polymeter, which I don't have.

You need a DC clamp meter to measure PV current. An ordinary multimeter can measure the PV voltage, though at this voltage level it would be safer to have a decent one (not a cheap one from a car shop). It would be good to measure the PV voltage at the PV input terminals when it is reading 120 V.

At a wild guess, your inverter's solar charge controller (sometimes misnamed the "MPPT") isn't working. Either it's not reading the voltage correctly, or it's doing something strange to clamp the voltage like that. Or something is preventing the MPPT from drawing significant power, e.g. high resistance in the PV cabling.

Your inverter seems fairly new (manufactured July 2024), and it seems genuine to me. So you should be able to get it repaired or replaced under warranty, though I realise that this may not be convenient when it was purchased from afar.

Hi. Thanks for your reply, once more. The PV input usually sticks around 120v. It rarely reads around 117–119 volts, but typically sticks around the 120v mark. I just went and checked it out, and it was on 120 volts again. However, sometimes the moment I tab into the PV input live data screen, it shows input voltage sometimes of around 300 volts, or around the 200 mark but then goes straight back to 120 volts for some reason.

I have “Canadian solar, CS6R-440T” solar panels with MC4-Evo connections. Since I needed to extend the wires to my inverter from the outside, I used regular wire with your common Mc4 connectors. I am wondering if there is a conflict between Mc4-Evo and regular Mc4 connectors. On the solar panel's pdf sheet, it says the following, although I am quite uncertain as to what that means:

Quote

Connector T6 or MC4 or MC4-EVO2 or MC4- EVO2A

I believe I could be facing merely a problem with the wire connections, although I am really not sure. The overall inverter feels very well-built, and is heavy for an inverter. I am currently charging my batteries are around 150-200watts, which is not enough to actually run my heater or any other power consuming appliance. I actually replaced Mc4 connectors on 2 of my wires that ran from my circuit breaker, and now I seem to be getting 5–7 Amps in, which is still very low for my solar system, even though it is very sunny today.

42 minutes ago, NoahAndArk said:

I believe I could be facing merely a problem with the wire connections, although I am really not sure.

Disconnect the solar string from the inverter and measure the Voc voltage of the string you should get 389v when the sun is shining.  Ensure the multimeter you are using is CATlll rated. If you get around 389v VOC also check correct polarity before connecting to the inverter mppt inputs. Should you still read 120v on the inverter display you might have a faulty solar charge controller.

Hello, thanks for the suggestion. I will do that and send the results here, waiting for the measuring device to arrive.

Well. I finally got the results. Here are two photos, I couldn't upload more as there is limit of megabytes on this website:

 

I really don't know what's wrong with the unit, both voltage and amps seem to be fine with the cables connecting to the inverter/mppt, but the amps are just not flowing out to the batteries. I checked the PV terminals on the inverter/mppt, and it read ~13 amps (clouds arrived). But when I look at the dashboard, it shows 0 amp input. I could really use some help. Thank you.

 

35 minutes ago, NoahAndArk said:

Well. I finally got the results. Here are two photos, I couldn't upload more as there is limit of megabytes on this website:

 

I really don't know what's wrong with the unit, both voltage and amps seem to be fine with the cables connecting to the inverter/mppt, but the amps are just not flowing out to the batteries. I checked the PV terminals on the inverter/mppt, and it read ~13 amps (clouds arrived). But when I look at the dashboard, it shows 0 amp input. I could really use some help. Thank you.

 

If as you say you measure 13A at the MPPT then it means all this power is going towards the load with zero to the battery.

Use the multi meter and provide the battery voltage and also what make/model of batteries are you using?

Oh! That's a good idea, perhaps I have wired the wall socket wrong coming from the mppt/inverter, I did see before the load icon pop up. Battery voltage is at 26.4v, redodo 2x 12v200ah batteries. Thanks for the response, Scorp!

Update. I disconnected all the loads, even the very wires. Still 0 amp input. After I took these two pictures, I went into standby mode, which does not output anything but charges the batteries, but still poured in 0 amps. I just want to bash that thing in pieces, at this point.

2 hours ago, NoahAndArk said:

Here are two photos,

Where are you measuring that 33.4 A? If it's using the clamp meter when the panels are connected to the inverter, then if the panel voltage really is 120 V, then some 4 kW of power is going somewhere. You can't hide that sort of power.

If that's short circuit current of the panels, please don't do that! We don't learn much from that reading. Though it does mean that your panels are fine, eliminating one variable.

Be careful with those high PV voltage MPPT inputs. When the inverter is operating, they have lethal voltages with respect to earth, even with nothing connected to the PV inputs. There are also capacitors on there that can store lethal charge for many minutes.

I'm wondering if there is a short circuit in the MPPT input, so the PV voltage is zero. That would explain the zero PV current. But it means also that the 120 V reading must be wrong as well. But don't use the resistance range on the multimeter without first disconnecting everything and measuring the voltage between the PV+ and PV- inputs. Don't attempt to measure the resistance if you see more than one volt there. Seeing tens of volts means that there isn't a short circuit, at least.

1 hour ago, Scorp007 said:

I couldn't upload more as there is limit of megabytes on this website:

Modern phones with their tens of megapixel cameras generate enormous images. Use Windows paint or similar to rescale the images to about 800 pixels max, or whatever is needed to show any important details.

Thanks for the reply. As you can tell, I am absolutely clueless at this point. I disconnected solar wires that were connecting to a circuit breaker, and I got a reading of 33 amps, but it was quite sunny then, I didn't manage to get the same reading later on. When I turn on the unit, it does show that it seems to be providing power to ac? Here's an illustration it shows me, when it is outside the standby mode:

I don't remember changing anything else really in settings, other than trying on 5th option the LIC mode, and later on the User-Defined mode. I have finally received the cable to serial adapter, perhaps there is something that I could try with it? Thank you, Coulomb.

Edit: my solar panels are currently covered in rain droplets, but I doubt that changes anything much. The best amperage I got, according to my memory, was 0.6Amps on the unit. Today I got 0.4amps, but then went back to 0 amps, yet magically I was exporting ~100watts to the batteries. No idea how.

Edited December 20, 20241 yr by NoahAndArk

1 hour ago, Coulomb said:

 

Modern phones with their tens of megapixel cameras generate enormous images. Use Windows paint or similar to rescale the images to about 800 pixels max, or whatever is needed to show any important details.

I normally just do a screen shot of pictures that reduces them by a good margin and then post the screenshot. 

Also a good move to reduce the camera resolution downwards when wanting to share the pictures on a forum. 

Edited December 20, 20241 yr by Scorp007

1 hour ago, NoahAndArk said:

Thanks for the reply. As you can tell, I am absolutely clueless at this point. I disconnected solar wires that were connecting to a circuit breaker, and I got a reading of 33 amps, but it was quite sunny then, I didn't manage to get the same reading later on. When I turn on the unit, it does show that it seems to be providing power to ac? Here's an illustration it shows me, when it is outside the standby mode:

I don't remember changing anything else really in settings, other than trying on 5th option the LIC mode, and later on the User-Defined mode. I have finally received the cable to serial adapter, perhaps there is something that I could try with it? Thank you, Coulomb.

Edit: my solar panels are currently covered in rain droplets, but I doubt that changes anything much. The best amperage I got, according to my memory, was 0.6Amps on the unit. Today I got 0.4amps, but then went back to 0 amps, yet magically I was exporting ~100watts to the batteries. No idea how.

You need to send us all your inverter setting, and if possible pictures of your installation especially your dc pv combiner db. Set your camera to the lowest resolution. Then download Resise Me from app store. Then use bulk rezise choose the pictures you took press done then choose 25% resize press done and the Resize Me softwared will create a new folder that contains the compressed pictures. Upload these pictures to the forum. You can upload in batches if you exceed the 3mb allowed. Below link to the software.

https://play.google.com/store/apps/details?id=com.xnview.XnResizeLite

Thank you, I will do that. However, I also read that if solar panels are connected in series, if one of them gets shaded all panels suffer with it. I have my solar panels on my triangle roof, where in the morning one side of four panels gets hit with sun rays first, while the other of four is on the other side of the roof, experiencing less sunlight. My inverter seems to have a startup voltage of 120 volts, so I wonder if perhaps my “series” solar panel connection is causing the issue. However, my solar panels are constructed using 3 bypass diodes, so there's that.

I will share the pictures in the daytime, although part of me does suspect the solar panels, as I previously measured the voltage of the wires coming into the circuit breaker being 120 volts. I really appreciate your help, it is either the solar panel connection that is causing the problems or the inverter, hopefully nothing is serious and is easily fixable. Will update later on.

16 hours ago, NoahAndArk said:

I disconnected solar wires that were connecting to a circuit breaker, and I got a reading of 33 amps,

I'm not understanding how you are getting a current reading when you are disconnecting something. Please don't disconnect PV wires under load; the resultant arc could grow to some 300 mm!!

I assume that you are using the clamp for measuring current. You need a circuit for current to flow.

12 hours ago, NoahAndArk said:

I previously measured the voltage of the wires coming into the circuit breaker being 120 volts.

Since the minimum MPPT voltage is probably 120 V, this could well be the crux of the problem.

You might benefit from firmware patched for shadow management, but there are at present only two of these, and none for your model.

Edited December 21, 20241 yr by Coulomb

Hello, it is another precious day. Here is what I've done. Previously, I had 4 solar panels on one side of my roof, and the other 4 on the other side (triangle roof). One side faced the sun, the other side was kept in shadow consistently, and had unequal sunlight reaching it. So, I disconnected that part that got no sunlight in good quantity altogether, and connected 5 panels on one side of the roof in series which faces the sun. Can't say it helped, but we had terrible frost, it will be visible on the pictures that I will share here. I thought that the 4 panels that go no sunlight, despite having diodes, were still causing issues for the MPPT/inverter. Here are all the photos I took:

 

Edit: planning to install that renogy thing on the batteries.

 

iloveimg-resized.zip

Edited December 21, 20241 yr by NoahAndArk

15 minutes ago, Coulomb said:

I'm not understanding how you are getting a current reading when you are disconnecting something. Please don't disconnect PV wires under load; the resultant arc could grow to some 300 mm!!

Sorry for the confusion, I wanted to say before disconnecting the wires, I got a reading of 33 amps, but it later stabilized.

I see photos of current measurements with the two probes stuck somewhere.

Do you realise that the current is measured magnetically by a current carrying wire inside the clamp? And the probes are only for measuring voltage?

It's possible that all the current that you are "measuring" is merely zero offset. Hall effect clamps are notoriously drifty, and have a terrible offset, that you have to clear with probably  the Z/F button, just before you slip one (never both) of the wires inside the clamp. After a few minutes of operation, you should check the zero, to get a feel for how much the value drifts. Slip the wire outside the clamp, but don't move the meter much if possible, as stray magnetic fields affect the measured value. Take the voltage probes off if they come off (usually they do), and swing the meter around to get a feel for how the meter behaves.

If you are well aware of all this, my apologies; it's always hard to judge how experienced any particular forum user is. Just that in all those photos, I didn't see any that showed clearly what was inside the clamp.

Edit: Your settings seem OK, though I didn't see setting 26 (bulk/absorb/CV battery voltage).

Edit 2: One of the phots says "previously used circuit breakers" or the like. What replaces them now? Ah, is that in photo p5, the same breakers outside the box for ease of voltage measurement?

Edit 3: Be aware that photo p4, which shows BATT and PV and 4A, probably relates to the battery side of the charge controller. So that could be about 0.9 A at 120 V being "DC transformed" down to some 4 A (anywhere between 4.00 and  4.99 A) into the battery at 25 V. As a rule of thumb, expect the current at the PV input to be some 5x (at 120 V) less than what goes into the battery. Note that there could be more panel current going into electronics, fans, losses, and also loads. Some models (not all) have a "data page" with actual panel current (as measured); those pages probably won't have the BATT segment on. Some models indicate total PV power as if it was all going into the battery, and some indicate net charging current into the battery. It's quite confusing.

Edited December 21, 20241 yr by Coulomb

Hi, Coulomb. I really appreciate your effort in trying to help me. In respect to the measurements I did, yes, I tried to not move the two poles as much as possible. I just don't think there is any sort of problem here in respect to wiring, as I connected everything as I should. Also, the frost/ice cleared on the solar panels, and still not getting any form of reasonable input. I am getting 0 amps again. But it is totally cloudy now.

I switched back to the circuit breaker with 4 mc4 connectors (two up, two down), just because the connections in the temporary version looked awful and unsafe. I just received a redodo battery charger, and switched that on to give life to my batteries again, as my MPPT practically doesn't work. I am thinking of getting myself a Victron 250/100 MPPT inverter, perhaps that would help, but I am just very disappointed as to what's happening with my solar system. It is a shame that there aren't any updates that I could download. 

Thank you so much for the help that I received here. I know more than I did before. You are good people. I am grateful.