4 hours ago, rowesley said:

Fhocorp, this hardware is very similar with the 3500W version I have discussed above which is using MOSBUS RTU protocol and where you can set the inverter MODBUS address in the menu and read it with Modbuspoll software. It's protocol is similar with SMGII inverter version (Easun, Powmr, Anenji, etc).

The 3500W inverter has two RJ45 jacks, one for RS232 and one for RS485 battery connection.

 

On your 3000W inverter, are you sure it's a host USB with 5V output? If so, it might be connected with a WiFi module which of course Vevor does not offer in the pack.

But, perhaps  instead of RS232 do you have an USB device connector? That is possible to make it compatible with Watchpower software. Just install the Watchpower, then reset computer, start the computer again, insert your USB cable in the computer, start your inverter, watch controlpanel/device and printer/ to see a new device, if everything is ok start Watchpower. You should see the inverter listed in the Watchpower left menu.

If not, sorry.

BEWARE to not use this inverter without battery connected no matter what is writing in the operating manual.

 

 

 

 

 

Hi

My voltmeter shows up a solid 5V output so is this an USB Host port. Yes it should be used for WiFi module or another plug in device.

In the settings it show a MODBUS parameter so it is not a classic Axper clone. 

I my case, i have no information about the wiring of the RS232 RJ45 connector (who is RX, TX or GND on the cable). The RS232 connector delivers voltage output because a WiFi Pro inverter WiFi module i have tested on it light up but doesn't reconize the inverter.

I want to setup a serial connection the my raspberry Pi running Solar Assistant software.

Best Regards

On 2024/08/31 at 3:38 PM, fhocorp said:

Hi

My voltmeter shows up a solid 5V output so is this an USB Host port. Yes it should be used for WiFi module or another plug in device.

In the settings it show a MODBUS parameter so it is not a classic Axper clone. 

I my case, i have no information about the wiring of the RS232 RJ45 connector (who is RX, TX or GND on the cable). The RS232 connector delivers voltage output because a WiFi Pro inverter WiFi module i have tested on it light up but doesn't reconize the inverter.

I want to setup a serial connection the my raspberry Pi running Solar Assistant software.

Best Regards

If do you have a RJ45 mother connector named RS232 on the bottom of the inverter near the RS485 RJ45 cable used for LiFePo4 BMS control,  then connection you need is almost sure the next one, just build your cable but DO NOT connect the VCC from RJ45 to pin 9 of DB9.

DB9      RJ45

9   Vcc    5

2   Tx      1

3   Rx     2

5  GND  8

With the cable above you should measure the following voltages: GND to Vcc = +13V, GND to TX = -12.6V, GND to Rx = 0V. Do not connect the Vcc wire in DB9 connector.

Connect the manufactured cable to a computer  by using an RS232 to USB adapter (a laptop running on batteries without being supplied with any adapter if you are afraid about AC currents flowing from inverter to laptop) and run Modbuspoll ( you can download an evaluation copy). I have the meaning of all important registers you will read with Modbuspoll , but I can post this info only on Monday.

Ok attached the internal registers of Vevor 3500W MODBUS inverter. Yours should be more or less the same.

communication parameteters 9600,8n1, reading holding registers ( address 03) useful data starting from addr 200 to 323. Between addresses 247 to 292 all registers values are 0.

 

Edited September 3, 20241 yr by rowesley
completion of data

4 hours ago, Coulomb said:

BE CAREFUL! It's possible that the USB port is only for diagnostics; it may not be isolated. Plugging it into a computer might cause large currents to flow and something may burn up.

I would check for voltage between the 0V of the inverter and 0V of the computer before connecting them. If you see a solid voltage (check AC as well as DC), then don't connect them!

Also, if  this is a Must/Powmr/other clone,  Watchpower likely won't recognise it. Having a menu item relating to RS-485 / modbus sounds very  non-Axpert to me.

Usually the processor in any hybrid inverter is isolated from AC, MPPT or battery charge section. All these modules have optoisolators for driving the MOSFETs or IGBTs. One workaround until you are sure: use a laptop running on battery ( no adapter plugged in laptop) and do not connect anything to earth ground on laptop connectors during tests. 

I've built an USB to USB optoisolated interface using Analog Devices USB isolator and DC-Dc converter but is far way too expensive for using it anywhere.

On 2024/09/01 at 12:34 AM, rowesley said:

Usually the processor in any hybrid inverter is isolated from AC, MPPT or battery charge section.

Not in my experience. All the Axperts I've looked at common the digital ground with generated AC-out neutral. That should be at roughly ground potential, but may not. 

On 2024/09/01 at 12:34 AM, rowesley said:

All these modules have optoisolators for driving the MOSFETs or IGBTs.

Yes, the power devices all have isolated gate drivers. But that's because their sources or emitters are high side or connected to BUS- or battery minus. The battery is isolated from everything, but the logic chips including the control board are not. 

The USB ports that are accessible from the outside are all isolated. Any internal USB port may not be isolated. 

"Not in my experience. All the Axperts I've looked at common the digital ground with generated AC-out neutral. That should be at roughly ground potential, but may not. "

Coulomb, for inverters having AC neutral not connected to the Earth neutral, you can connect it outside.  To avoid damages, use a 25W Edison  bulb in between AC output and Earth ground, if the filament stays cold ( no current flow) replace the bulb with a wire.

Once your digital ground is connected to the Earth ground, the computer ( which has his ground connected to Earth ground through the supply cable) is safe. Laptop is safe as well since the adapter SMPS is isolated and it's ground is internally connected to Earth ground with a HV capacitor.

Experience is a mater of age. You know more near the retirement, when anyway it does not matter what you know...nobody care🤪

Hi everyone, i have good news today

Based on RS232 pinout, i finally managed to work the communication on the RS232 port 😆

The inverter is an Sumry hybrid inverter (unknown model). Solar Assistant detect correctly all the datas (battery, watts, PV voltage...etc).

Actually all is working but 2 anomalies remain to be treated :

- The solar inverter doesn't charger the batteries without the 230V inverter powered on (most of the devices automaticaly boot up and charge the batteries when solar panel supply volteges but this not working here.... very embarrasing for getting the batteries fully charged even if the inverter is unused.🤨

- The internal Fans of the inverter are always working at medium speed, even when the device is idle. It consumes 20W on the battery. Not found any parameters on the device to modify it. Maybe i will have to replace the fans or install a custom board for controlling the fans...😐

I you have some ideas 😄

The fun fact is that Solar Assistant show me in inverter details a serial number that is completely different from the one on the casing. Rebranded clone...😐

Thanks for all your help 🙏

Here is the screenshots 😁 :

Edited September 3, 20241 yr by fhocorp

4 hours ago, rowesley said:

Once your digital ground is connected to the Earth ground, the computer ( which has his ground connected to Earth ground through the supply cable) is safe.

I've just read too many posts from people blowing things up by plugging in a USB or RS-232 cable. I think in some cases, a portion of the load current returns through the earth wire of the USB port.

Has anyone successfully connected the Vevor Hybrid Solar Inverter to a computer? The RJ45 to RS232 cable isn't working with the standard pinout I’ve tried, and the manual lacks details. The inverter operates but has significant measurement errors. Any advice or solutions would be appreciated. For a reliable residential solar system, check out Cosmo Solaris!

13 hours ago, wilianwalker said:

Has anyone successfully connected the Vevor Hybrid Solar Inverter to a computer? The RJ45 to RS232 cable isn't working with the standard pinout I’ve tried, and the manual lacks details. The inverter operates but has significant measurement errors. Any advice or solutions would be appreciated. For a reliable residential solar system, check out Cosmo Solaris!

 

Read previous posts, it works for me.

20 hours ago, Coulomb said:

I've just read too many posts from people blowing things up by plugging in a USB or RS-232 cable. I think in some cases, a portion of the load current returns through the earth wire of the USB port.

Yep, you have right. USB isolator then.

Vevor EML3500-24L does not have factory default any thermal grease between the MPPT power transistors and heatsink. Transistor drains are electrically connected with the heatsink . This is killing at least one transistor very quickly.  The picture attached shows the transistors which need thermal grease, the TO247 parts on the edges.

18 hours ago, wilianwalker said:

Has anyone successfully connected the Vevor Hybrid Solar Inverter to a computer? The RJ45 to RS232 cable isn't working with the standard pinout I’ve tried, and the manual lacks details. The inverter operates but has significant measurement errors. Any advice or solutions would be appreciated. For a reliable residential solar system, check out Cosmo Solaris!

 

It is working for me sir, just follow the wiring that rowesley explained

5 hours ago, rowesley said:

Vevor EML3500-24L does not have factory default any thermal grease between the MPPT power transistors and heatsink. Transistor drains are electrically connected with the heatsink . This is killing at least one transistor very quickly.  The picture attached shows the transistors which need thermal grease, the TO247 parts on the edges.

Hi @rowesley this is mandatory for working ? I have tested 500W Resistive power but no high temperature measured in this part ? You have to dessolder the heatsink and the mosftets for adding thermal grease ? I suppose that i can just unscrew the mosfets from the heatsink and add thermal sticker between the mosfet and the heatsink.🤔

For the 20W power without load, i suppose this is due to the FANs that consume too much energy. These are 4 Pins in 12V 0.7 A in 80mm, i suppose i can replace them by Noctua Fans for quieter working and save more energy (0,07A max !)

Currently, i have no idea about the way to have the integrated Solar charger that automaticaly starting when the inverter is off 😔

Best Regards

The Vevor EML3500-24L is a Sumry inverter made by the chinese manufacturer Shenzhen Sunray Power Co., Ltd

On the alibaba website they sell it with OEM Customization options. This is here were VEVOR inverters are made.

https://www.alibaba.com/product-detail/Sumry-brand-2023-new-design-1800W_1600673209137.html

I have contacted the supplier for more informations about the inverter (firmware, shematics....) for helping us. No warranty if they answer me about this.

 

Best Regards

Fhocorp, this is my third email trying to answer, there is a problem with this forum.

Both MPPT and DC charger heatsinks need termal grease. 6xTO220 transistors on charger side with simple heatsink removal no desoldering need, 2xTO247 transistors on MPPT which need desoldering for 5 devices as pointed in a picture above.

The MPPT should be supply below 150V. If not, the MPPT transistors will crash even with small load. The battery voltage is available on the MPPT input on this model.

You will get no service what so ever from any Chinese company. Vevor is opening tichets, after a long debate, requiring pictures, movies, etc, they will send directly from China a replacement board, which of course does not fit for your inverter. If you have 3500W inverter they will send you 5500W power board, or a 3500W power board suitable for other model. If you will complain about that they probably will say to send it back to China and wait for a replacement.

What I'm saying is based on my experience with Vevor. However, this inverter is much-much better than Easun models which btw draws 30W form battery and 30W from AC ( no matter it is sun or not). Also the Easun 3500W model with 6000W MPPT is consuming 200W on bypass mode.

Do not touch fans control, they need to blow.😂

 

1 hour ago, rowesley said:

Fhocorp, this is my third email trying to answer, there is a problem with this forum.

Both MPPT and DC charger heatsinks need termal grease. 6xTO220 transistors on charger side with simple heatsink removal no desoldering need, 2xTO247 transistors on MPPT which need desoldering for 5 devices as pointed in a picture above.

The MPPT should be supply below 150V. If not, the MPPT transistors will crash even with small load. The battery voltage is available on the MPPT input on this model.

You will get no service what so ever from any Chinese company. Vevor is opening tichets, after a long debate, requiring pictures, movies, etc, they will send directly from China a replacement board, which of course does not fit for your inverter. If you have 3500W inverter they will send you 5500W power board, or a 3500W power board suitable for other model. If you will complain about that they probably will say to send it back to China and wait for a replacement.

What I'm saying is based on my experience with Vevor. However, this inverter is much-much better than Easun models which btw draws 30W form battery and 30W from AC ( no matter it is sun or not). Also the Easun 3500W model with 6000W MPPT is consuming 200W on bypass mode.

Do not touch fans control, they need to blow.😂

 

@rowesley you can send me PM if you have to contact me If required, i can also send you via PM my personal email for discuss things more calmly.

OK, your problems with VEVOR support are the sames as mine. I my case, i have sent a bunch of messages about the problems that i have measured on the product (FANs noise, auto-start of the MPPT charger not working without then inverter on, 20W consumption with no load and the lack of informations about the RS232 port) and they resend a new inverter to me. So, i am not expecting support from china supplier but if i can have some informations it can me very useful. I have personnaly modified my inverters, based on my researchs and your advices for my personnal installation. I have even tried to connect the 2 inverters in parralel (on the 230V output), it works but without direct communication between the two inverters (via a dedicated port) the 230V phases are not syncronized. I am actively searching a firmware file for customize some advanced parameters (ex FANs speed should work based on temperature of the heatsink and not the load for quieter working).

For the thermal grease, i will do this ASAP on my inverters (they will be installed inside a server room and i don't want to see them burning linke Easun inverters😵

For the FANS, i will never remove it ( i am not crazy 😁) but i will remplace them with high quality FANs (Noctua) for quiter working and more cooling performances.

For the difference between VEVOR inverter (based on Sumry brand) and  Easun, i am completely agree with your opinion. I very often have repair requests on Easons with the main fault being the inverter power bridge or the MPPT which burns out.

 

Today, one of my VEVOR inverters suddently reported error on the DC side (Solar Input). I have shutdown the inverter, disconnected all the cables, and waited about an hour for discharging the capacitors before opening it.

I have found the capacitor on the MPPT input (680uF 200V 105*c) completely bloated. I have replaced him with a new one but i have foud that the soldering is very hard to remove enven with my dessoldering station. Bad tin used for sweating the components...

@rowesley , did you encounter any difficulties when unsoldering the MPPT power bridge?

 

@rowesley , did you encounter any difficulties when unsoldering the MPPT power bridge?

No because I have around 40 years of hardware experience. Use good solder wire (60%tin-40%lead) and mix the lead on the board with it first. Use a solder iron of about 60w, then use a good tin pump. 60w electric tin pump is good as well, bit solder will be spread all over around...😂

The "lead free" chinese boards have a poor solder...maybe is not 60%lead but is definitely somehing else than tin.

You have to replace that PV input capacitor with a 6000h or 10.000h one (10-15 euro pcs). Use 200V one or even higher value.

You have also to check Q6, Q8 transistors from the heatsink I've take photos and the output of U10 driver. One of the transistors may have short circuit between drain and source. But you have to replace both with the same type. Take a magnified view of the picture posted and see the replacement type, there are already mounted on heatsink.

You should also check two parallel capacitors of 680uF/35V, I do not remeber those part numbers. Good luck.

BTW, there is no MPPT bridge. Just two MOSFETS connected in parallel and three double switching diode...

Edited September 8, 20241 yr by rowesley

1 hour ago, rowesley said:

@rowesley , did you encounter any difficulties when unsoldering the MPPT power bridge?

No because I have around 40 years of hardware experience. Use good solder wire (60%tin-40%lead) and mix the lead on the board with it first. Use a solder iron of about 60w, then use a good tin pump. 60w electric tin pump is good as well, bit solder will be spread all over around...😂

The "lead free" chinese boards have a poor solder...maybe is not 60%lead but is definitely somehing else than tin.

You have to replace that PV input capacitor with a 6000h or 10.000h one (10-15 euro pcs). Use 200V one or even higher value.

You have also to check Q6, Q8 transistors from the heatsink I've take photos and the output of U10 driver. One of the transistors may have short circuit between drain and source. But you have to replace both with the same type. Take a magnified view of the picture posted and see the replacement type, there are already mounted on heatsink.

You should also check two parallel capacitors of 680uF/35V, I do not remeber those part numbers. Good luck.

Wow, thanks for all your advice 🙏

I have replaced the faulty capacitor with the same values and followed your advice for the thermal paste (added thermal paste on all the MPPT and DC mosfets.).

At this time, my inverter is working correctly, i will check Q6, Q8 and U10 when i will open the device for replacing the fans. 😃

Thanks sir 👍🙏

1 hour ago, rowesley said:

BTW, there is no MPPT bridge. Just two MOSFETS connected in parallel and three double switching diode...

Ok sir 😃 So this is not a real MPPT on the device ? A fake one ?

21 hours ago, fhocorp said:

So this is not a real MPPT on the device ?

Unclear so far; more photos might confirm. But all the low PV voltage Solar Charge Controllers are by ck converters, not full bridges. So not 4 separate switching devices, effectively one switch, typically made up of 2-6 devices in parallel. To complicate matters, Voltronic often use an interleaved design, effectively two buck converters. 

An interleaved SCC is like the below, except that for convenience the transistors are in the negative side, not the positive side:

The right hand transistors in the above are synchronous rectifiers for added efficiency; they are omitted in all the real SCCs I've examined, using ordinary high-speed diodes instead.

You can tell if it's interleaved by the pair of inductors, usually off-board.

Edited September 9, 20241 yr by Coulomb

Coloumb, this is not the case of Vevor MPPT. The low cost hybrid solar inverters have a simple buck or boost topology for MPPT depending of internal BUS required voltage value.

If internal BUS is higher than PV (usually max 500V PV input devices, around 250V-300V nominat PV input), then is BOOST. Easun has the same topology. Voltronic price is twice to third time higher compared with  Sumry (Vevor) so it might have tricky things. I did not reversed engineered the Vevor MPPT schematic, but I did for Easun. Vevor is the same by simple measurements ( paralell connected trasistors)

For Fhocorp: MPPT means a PWM (puls width modulation) of which the duty cycle depends on product between U and I from PV.

So, in a low cost MPPT you will have one or two MOSFETs connected in parallel , one big coil and a number of diodes in anti-parallel between drain and source of these transistors. When there is a lot of energy on the PV, the ON conduction time will be high while the OFF blocking time will be low. The processor will try to keep the input power near the ideal UI curve of the PV by measuring U and I and controlling accordingly the ON-OFF time of PWM. Vevor MPPT is following very well the input UI curve for low PV energy input (small ON conduction time). Of course, when it works. 😂

Edited September 9, 20241 yr by rowesley

11 hours ago, Coulomb said:

Unclear so far; more photos might confirm. But all the low PV voltage Solar Charge Controllers are by ck converters, not full bridges. So not 4 separate switching devices, effectively one switch, typically made up of 2-6 devices in parallel. To complicate matters, Voltronic often use an interleaved design, effectively two buck converters. 

An interleaved SCC is like the below, except that for convenience the transistors are in the negative side, not the positive side:

The right hand transistors in the above are synchronous rectifiers for added efficiency; they are omitted in all the real SCCs I've examined, using ordinary high-speed diodes instead.

You can tell if it's interleaved by the pair of inductors, usually off-board.

 @Coulomb  Wow 😲Thanks for the information 😁

5 hours ago, rowesley said:

Coloumb, this is not the case of Vevor MPPT. The low cost hybrid solar inverters have a simple buck or boost topology for MPPT depending of internal BUS required voltage value.

If internal BUS is higher than PV (usually max 500V PV input devices, around 250V-300V nominat PV input), then is BOOST. Easun has the same topology. Voltronic price is twice to third time higher compared with  Sumry (Vevor) so it might have tricky things. I did not reversed engineered the Vevor MPPT schematic, but I did for Easun. Vevor is the same by simple measurements ( paralell connected trasistors)

For Fhocorp: MPPT means a PWM (puls width modulation) of which the duty cycle depends on product between U and I from PV.

So, in a low cost MPPT you will have one or two MOSFETs connected in parallel , one big coil and a number of diodes in anti-parallel between drain and source of these transistors. When there is a lot of energy on the PV, the ON conduction time will be high while the OFF blocking time will be low. The processor will try to keep the input power near the ideal UI curve of the PV by measuring U and I and controlling accordingly the ON-OFF time of PWM. Vevor MPPT is following very well the input UI curve for low PV energy input (small ON conduction time). Of course, when it works. 😂

@rowesley  Thanks for all the knowledge 🙏  Actually, my first Vevor is connected to a 180W solar Panel for testing. The second inverter is not connected to solar panel (not received yet). I am planning to connect 500W of solar panel on each inverter. I am wondering to connect the inverters together for having 2 phase electric output (and maybe tri-phased system for my Laboratory) but they don't have any parralel connector available. I have know that it is possible to connect the neutral output of the inverters together for multiple phase output but only if the inverters share the same input battery, that's right ? If yes, there is a way to use 2 different battery with the negative pole in common ?

Here is a schema of i want :

10 hours ago, fhocorp said:

I have know that it is possible to connect the neutral output of the inverters together for multiple phase output but only if the inverters share the same input battery, that's right ?

I think it should be OK to connect the AC-out neutrals together. You only need to parallel the batteries with Voltronic inverters when you actually parallel the outputs (lives as well as neutrals), or you want a genuine 3-phase configuration.

I'm curious as to why you want to parallel the battery negatives only.