WVC-600 inverter review

This site relates my experience with WVC-600 grid tie solar micro inverters, after one year of use. You probably will have the same problems with other models as they use the same technology: WVC-300, WVC-1200, WVC-700, WVC-1400…

wvc600 inverter

1- Unreliable and dangerous
Two WVC-600 inverters stopped working after only one day of use, one of which burnt.

2- No warranty
The seller refused a return to repair/exchange, arguing that they only sell brand new WVC-600 inverters.

3- Poor efficiency
With twelve 300W solar panels, a total of 3600 Watt, I only managed to get 3000 Watt at most, which is an efficiency of about 83%. Now, after one year, it’s down to 2600W.

4- MPPT is defective
With 6 micro inverters connected, the MPPT never lock. The system sometimes stays blocked at a very low production (200w instead of 3000) until the main AC is turned off and back on.

5- WVC Inverters are not properly tuned
WVC-600 micro inverters are reporting eccentric values through the WVC modem: AC at 290V, or output power higher that input, etc…

6- The constructor doesn’t reply
After multiple requests to the constructor, Dongguan KaiDeng Energy Technology Co, asking for help (or at least schematics), I’ve never got a response.

I will detail in future articles every point listed here. Opinions are my own. You might be luckier than me with these Chinese micro inverters.

86 replies on “WVC-600 inverter review”

Hi! I have a WVC-600 that I bought from ebay. After a day, rather 19 hours, the inverter stopped working. There is no LED light and no AC output, despite dc input from the panels. I have preformed basic tested on the inverter and have determined that the DC inputs are not shorted, but don’t know where to go from there. Have you had any luck repairing these inverters? Thanks!

Hi Zack! One of my WVC-600 did the exact same, stopped working at the end of the first day of use… The input Mosfets died. Those are the four IRF3710.
I’m interested to know how many inverters you had plugged-in when it happened, and how many watts did you put in?

I have (or had) a single WVC 600 that operated ok for a couple weeks with one 72-cell 9 A PV panel, but failed soon after second PV was plugged in. I presumed to have surpassed input power capacity for the inverter. All input MOSFETs shorted out and, even after removal, the short persists. Most probably transformer windings insulation enamel melted away. It run very hot after second PV connection.
Have you opened any of your fried inverters?

I bought some IRF3710 for replacement but my inverter has not those FETs. It has 8 kinda SOIC-8W packaged FETs, in 4 parallel sets. They were so cooked I couldn’t read any info on them.

Hi Paulo,
This is very surprising! I’ve opened a few of these inverters now, and I only had IRF3710 as input mosfet.
Burning the transformers is unlikely, but I guess I haven’t seen everything yet with those wvc-600… Beside, the specs says “Maximum Input Current 24A” so two 9 amps panels should be perfectly fine.
However, how much voltage do they produce? The input caps are rated 50V. (50 Chinese volts)
I would check those caps, especially if you still have the short without the fets.

Thanks for your reply Seb.
Open circuit maximum voltage is 48V and besides I checked all 4 caps and they are fine.
After removing all 8 original tiny Fets no short remains. Even after installing 4 IRF3710 still no short, but as soon as I connect PVs their voltage drops to zero. Disconnect PVs and no short. The only explanation I could think of is the inverter is not switching input Fets.
What do you think? Do you have the schematics for these things?

Hi Paulo,
If the Fets are not switching, you should check D7 / Q7 and D5 / Q5.
It could also be U4, but I don’t know what it is as they removed the reference…

Seb, you seem to have good knowledge of these inverters. On my WVC300, C-41 was shorted internally and brought down 12v supply rail and 5v processor power. C-41 goes to pin 13 of U4. Do you have any specs on C-41? Depending on it’s use the exact capacitance of C-41 may not be critical. Thanks for any help.

From the spec, the max DC input is 50v. A 72 cell panel nominal voltage is 48v, but can and will exceed that, especially on a cold morning (look at the specs for your panels – apply the formula for open-circuit voltage vs temperature, and you will see what I mean. This must ALWAYS be factored in when choosing compatible components. This unit should only be used with 60 cell panels.

Thank you, but I’ve already sent emails to Kaideng and they do not reply. It’s been a year now, with 6 inverters dead. I’m not the only one to have problems with these inverters. Chinese companies like this, who sell crap without warranty or support, should just not exist. I don’t have much time and I’ve lost a lot already, but I intend to detail everything here so people that want to buy this shit are warned.

I have had the wvc-600 running with two 195W panels for two years without problems. I recently tired to chain the wvc-600 to a new gbt-600 with a single 195W panel and the gbt-600 died after one day with the DC input shorted. I got a refund on the gbt-600 and purchased another one from a different supplier. The second gbt-600 also died after one day again with the DC inputs shorted. I have repaired the gbt-600 and used it in isolation with two 195W panels and has been working for several days now. I can only conclude that chaining the wvc-600 with the gbt-600 is not supported due to some incompatibilities. Any thoughts on how to get these working together?

Hi Bruno, I never heard of the gbt-600. Where did you buy it? But yea, for grid tie inverters it’s better to keep all the same kind. That’s why I’m stuck with the wvc 🙁

Sorry I had a typo, they are gtb-600. They look identical to the wvc-600 except that they include WiFi for monitoring. You can buy them from the same places you buy the wvc-600, ebay, AliExpress and other Chinese sites. Since I wrote my first post my gtb-600 failed and the dc inputs are shorted so it turns out not to be a compatibility problem but a problem with the inverter itself.

My first WVC-600 works for 2 years without problems, the second one for 1,5 years to. They’re connected with 2 285W qcells moduls (first) and with one 285 qcells modul (second). My third WVC-600 works on battery-bank over stepup-converter to support my grid (max 300W permanently) for an half year also without problems. Maybe you must not overload the device (for example 500w permanently), then the WVC600 works reliable. The temperature increases to over 60 degrees during overload 500W.

Yes sure! It’s rated for 600W but I think I will use them only by night. That way they wont overheat.
So, really, what’s the point of selling inverters for 600W if you can only plug one 285W panel?
I would never have bought them if someone had told me that.

Maybe you misanderstood: On first WVC there are 2 modules of 285W connected. Southwest direction, 30 degrees, the second connected to one module. There is no problem to undersize, there is only a problem to oversize the WVC. And yes, the third on batteries is particulary used by night :-). I choised it caused reliability, not primary power optimised. And they do that…

Hello Erwin,
I would like to connect my WVC-600 to my 48V battery (so no need any DCDC conversion). Do you think I’d need to limit the input current to the inverter? Or does the WVC-600 adjust the DC input current from the battery on its own?
Thank you all by the way for your feedbacks on this product. It helps a lot (even though it is not very reassuring)

Sorry for answering so late. First you have to limit the input voltage to 37V for example with a stepdown-converter. And it is strongly nessesary to limit the output-current of your batteries. Never connect the inverter direct to a battery! In this case the inverter cannot find the point of maximum power (mpp-tracking). the maximum power of a battery ist for example 3 kW (lead battery) or higher (for example lifepo 20kW). the inverter can only used with 500W continuously. caused of that fact you have to limit the current into the inverter. in a simple case with a resistor, but this is not energy-efficient. Another case is to use an controllable stepdown converter (control input an output voltage and output current). the optimal case is to use an pwm-modul to connect the inverter. detailled infos you find in many pv-forums. read carefully, its not very difficult, but there are many problems to consider protection against electric shock as well as technical protections.

These are designed for 36V (45V open) PV’s mosfets are junk, but replacing them will make the device even harder to break. the modem can be replaced with hc-12 for $5. The device is great for the price.

Good Day, i bought a GTB-600 micro inverter to connect it to two 300W Solar panels with 42v open voltage each, 72 cells
The inverter did what is should do for one day and the next day it became dead. I think the temperature underneith the solar panel, where the micro inverter is mounted becomes too hot in the Filipinne sun and its burned out now. I ordered a new one and insullated the area underneith the solar panel to reduce the temperature is geting too high again.
What i read in this forum makes me believe that Chineese electronics are not reliable for long time. I five it one more try and see whats happen?

Bonjour, idem chez moi sur ce micro Inverter WVC-600
il a fonctionné peu de temps, toutefois les condo vert semblent ok
comment je peux vous envoyer une photo? cordialement

Hi, My WVC-600 stopped working after 10 months with 2x 300w panels. No lights. Mosfets look fine but ceramic disc capacitor at c16 has burnt off completely. C15 is there but unreadable. (I think it might be JEC jd222my1 as it looks the same as is at C6) Can anybody confirm what C15 and C16 should be?

Hi Nige, I think those are the class Y capacitors, 2.2nF 3kv. If they are not shorted, or if you remove them, your device should still work. Also, as it is the output, the light should be red (no AC). No light indicate that there is more than that…

My experience has been mostly positive, but then i’m not running a larger system like most on here. I have a single Mars Rocks WVC-600-110V (110volt model) purchased in March 2019, fed on one side by a pair of 150 watt rated polycrystalline panels wired in series. I have had flawless operation since and typically see ~250 watts when the Sun is facing dead-on to the PV’s. With the temperature of the PV’s reducing output and factoring inverter loss i’m still seeing about 80% of my panel output ratings. I’m happy with that. Once on a cold sunny day with a cold wind I briefly saw my system spike to 290 watts for several minutes.

However, even though the inverter is shaded, mounted away from the PV’s, and has lots of air circulation, it can get uncomfortably hot at times especially in summer. I had planned to get another pair of PV’s and use the 2nd DC input on the inverter but concern about putting added heat stress on the unit has me having 2nd thoughts about doing that.

Hello from Greece, I have one 1200w inverter and yesterday one of the two led stay red. Does anyone know what is the error or what to look / search for error?
I have check the panels, and the ac input and they work. But the inverter never gets green.

Hi, red light typically means that AC is not detected. You should open it and check the fuse (near the AC plug). If it’s blown, check if there’s a short on the output Mosfets.

Hi Seb.
Thx for the Faast Reply.
Sorry for my bad English.
So the red Light is only On when Connected to rhe GRID but there is no Light when Disconnected from the Grid.
The first Inverter i opend and i could not see anything Burnt or Broken? Is it on the Backside? How does the Short on Mosfet looks like?

Hi Darko, the mosfets are on the edges of the board (TO220, 3pins). You can test them if you remove the back cover, check for shorts between each pins. There are 2 for each input, and 4 on the output.

Hi Darko and Seb,
I have the me problem: AC no longer recognized after 2 weeks (light stays red, no click noise when plugged to grid). In the two weeks, sometimes the ground fault circuit interrupter was tripped sometimes.

I checked the fuses, they are fine. Also I checked the mosfets, no shorts. I have 2 WVC600, and actually I could not find any differences between the working one and the broken one when I check the diods, input/output mosfets and fuses.

I would be very thankful for any further tips or ideas to check. Thanks a lot!

Hi Everyone.
Sadly i just read this now…
I have 5 of the 1200watts Microinverters
And 1 of the 600 you all talking about.
The 600w one works for months now perfectly
The 1200w i purchased 2months ago tested em today with only 3 Panels 285w
The first inverter worked for 14days and died
Smelt bit burnt and thats it no light no reaction

Then i installed a 2nd one (planned to do 20 panels on 5 Inverters) this time i installed only 2 panels.
The light is red but only when conmected to the Grid if its disconnected its not working/detecting light from the Panels.
I testet Panels amd Grid they working fine so seems i also shorted something on the 2nd Inverter.

Seller wont reply even he Promised 2 Year Warranty.
Hope i can Fix it myself somehow with Quality products or should i just let it go?
I mean i paid 1000Bucks for all….

Hey Darko, it makes no sense to buy the wvc-1200 as there is only one MPPT for the four panels.
I’ve been repairing my wvc-600 regularly for two years, but at some point started to get annoyed and swapped them all with APSystems QS1. Also Chinese but seems much better quality. They are working flawlessly since December, but I’m waiting to see how they perform on summer. I get 3500W instead of the 2600W with the wvc piece of junk (and they have one MPPT for each panel).
1000 euros is about what I lost too… not counting the parts for repair.

My WVC600 connected to the panel and only showing red light what is th e condition.
earlier when connect to the panel blinking led, now its only showing red color only

Hey Seb.
Sadly 700USD Gone!
2 Inverters are so Broken that all Mosfets are Shorted, the AC Mosfets burnt to a crisp cannot FIX just big Junk.

I hope anyone who sees this should know instead of the 800USD spend another 1000 for something better with Warranty and close to your Home!

i now Ordered new inverters here at my Local Solar Store 360USD per Piece yes Pricy but 12 Years Warranty!!!

Hi Seb (or anyone else that can help). I have a 600W which blew the mains fuse (internal) , probably some of my fault. I think the MOV might have done its job but now the fault is persisting. Do you know the value of the MOV (RTV1) as mine has a wierd cylindrical one with no obvious markings.

Hi Chris, RVT1 is 10D471K. But, it should work without it. If you still have a short, it’s probably a blown mosfet (RF7, RF8, RF17, RF18)

Thanks Seb. I just put a meter on the mosfets and RF18 does indeed apear S/C, the others look good. Not sure what the part numbers are ye as I can only see the legs until I strip it down some more. The fault happened when I was unplugging the mains at night.

Hi Again, Just taken to pieces and the part is 30NM60ND the STF variant. Looks like ST have stopped producing this but several clones appear to be available. I will replace all 4 incase the ones that look good have been stressed (more than me).

Hi Seb, all repaired and working again now. Yes the model I have is different to yours. Even though on the outside is says WVC-600W the PCB says WVC700. The app is OK and also shows the temperature but I am not sure where the probe is. I asked aliexpress for a refund and they are refunding a portion so it will be interesting to see how long my repaird unit lasts. Thanks for the help

Guys,

I bought 12 inverters model WVC1600W connected each on 4 panels with 360 W max output. Total costed more than 1300$ + shipping.

These inverters DO NOT WORK.
*** DO NOT BUY THEM! ***
The KaiDeng company is at fault. All the WVC inverters are poorly designed.

Some of my installations work with inverters of another brand and the results are excellent. By replacing the inverter of another brand with a KaiDeng WVC, it no longer works.

I made several measurements including a precise measurement of the output power logged every 4 seconds. The result is clear: my “other brand” inverters work all the time (when there is sun) and the WVC1600W only work part of the time. When they do work, their efficiency is much lower than that of the other brand. This is a disaster.
Unfortunately, I don’t know how to post a picture here.

Stay away from them!

Hey Laurent, very sorry you’ve spent all that money on these pieces of shit. I’ve originally made this blog to warn people not to buy the WVC inverters, but it looks like everyone is coming here looking for info after buying, because they either do not work well or just don’t work at all.
I think I will turn this blog into a forum, that we can post pictures and help each other on the improvement and repairs.
Thank you for your feedback

i know this site is called “wvc-600”.
i see it exists as a warning.
however a warning without alternative is kindda useless?
so … what’s better?
hoymiles? ben(i)j?
which microinverters work with which ac-coupled battery inverters (bat-inverter providing a ” fake” grid during “real” grid blackout for “overriding” anti-islanding” protection).
thanks for making website and sharing info.

Hi! I have also made the mistake of buying one WVC-600. After a few days of operation it stopped working. I opened it today and found F1 to be gone and after finding your hints to look for the MOS-FETs and the Zener-diodes I found a strange looking conductor path on the PCB from RF18 to ZD5. Any hints what I should check and measure and/or replace?

Hi Seb,
Thank you for your answer. I was able to return 7 out of 12, with refund. I am still playing with the 5 I still have.
Thanks for doing all this!

Just a note to tell you that out of the 5 that I had left, 2 burned…

In one of them, it’s one of the transformers that is now walking around in the case. In the other one, all the caps of the capacitors have blown. Very elegant. The other three had MPPT regulation problems but I have now disconnected them because I still care a little about life.

But I discovered something else. I bought 1600 W versions and that’s what it says on the label on the outside of the case. You know what? The engraving on the PCB says 1400 W! And that can’t be right either because they were loaded at 775.6 W when they burned out.

Good luck to all.

Hi Laurent,
See my post below this one – my WVC1600 that failed also appears to have one (possibly two) cooked transformers. Also, like yours, the label on the outside is 1600W and the PCB says 1400W.
This is not ALWAYS a sign of re-badging – sometimes the 1400W PCB, 1600W PCB and 200W PCB might be identical – it’s the Bill of Materials (BoM) used in the build that matters (different components for different models). Of course, with no schematics and no BoM we have no way of knowing. With incorrect labeling it could be any of:-
o OK
o An assembly cock-up
o Deliberate mis-labeling of the outside (lying / cheating)
I’m keen to learn how to mend/improve these darn things … but I’m also keen to learn what better alternatives folks have found?
Best of luck,
Kind Regards,
Spenser

Hi Seb,
Many thanks for a great site. Like most of your readers I WISH I had found you BEFORE buying.
My second wish relates to your 7th July post – a Forum where we can share repair (and better still) “improvement” know-how. Yes, please.
Like Laurent I have WVC1600 (only x2).
My Good News … I bought from Amazon. When the “lovely” Chinese seller replied to my 3 month failure with “Velly Solly. No can do. Thank you for understanding” … the Mighty Amazon stumped up a full refund (which I then invested in a 2000W replacement (same crap, different seller) – again before I found your site. Well, it’s working so fingers crossed – maybe I can improve things, too?
Anyway, that leaves me 1 x WCV1600 to repair (I’d always planned on having a hot spare – just didn’t seem urgent)
In my case the AC side shows no signs of stress. The problem is 4 (of 8) input mosfets are cooked (along with the PCB). These are (substantial TO220) parts – IRFB4115’s – should be man enough. Everything points to the gate drive circuit which is fried (and will need re-building)
Has anyone worked up a schematic for this part of the circuit – worth asking before I start.
The other thing… does anyone have a source for transformers (mine are KDWC700W 25-40 – so a custom part?) – maybe I should offer to buy one of Laurent’s dead units for spares? A forum for this might be useful in itself.
I suspect the PIC software could be improved. Source code or reverse engineering might address the efficiency (and heat) issues? Anyone?
BTW – I used to work with designers and manufacturers in China (never with KingDong, or whatever they’re called). It’s possible the design is actually OK and mass-production and manufacturing are at fault. Chinese board-stuffers can be absolute cowboys if you let them – made worse by component shortages?
Anyway, thanks again.

Kind Regards,
Spenser

Hi, my WVC 700 has stopped working, I get the red flashing LED and then briefly a click from the relays, the back to flashing. I’ve tested the input power FETs no shorts across the pins, however the power Schottky diodes D18, D19, D24, D21 pins 1 and 3 are shorted for all. D26 seems fine, can anyone please tell me if they are shorted in circuit or could they be faulty?

— “The system sometimes stays blocked at a very low production (200w instead of 3000) until the main AC is turned off and back on.

This is the same that I see on my wvc-700 series 3 version aswell.
Can produce 8-12w , and after a power toggle in the Cloud Intelligence app it goes straight to higher watt; on good sunny days over 500w

It realy struggles if the cloud is the dark one and rappid change between sun, and cloudy. It never gets back into production, if you don’t flip the power.

Any fix we can do ourself ? other than buing other brands offcourse 🙂

Hi Rune – these ideas might also help Martin K below… ? …

I’ve NOT seen this issues but reading Seb’s comment at the top of the page “With 6 micro inverters connected, the MPPT never lock” I did ponder the issue – not least because this would make me hopping-mad if it happened to me.

I did wonder if this is/was a symptom of connecting mains to the units in a string? Or does it happen with a single unit connected to the mains?

When I replaced my duff unit I became aware of a lot more “noise” on the mains. I don’t currently have the equipment to analyse this (and it’s not causing me a problem) – but I suspect “noise” could cause this issue. All grid-tie devices need a lot of instrumentation to monitor the mains (to provide MPPT and anti-islanding) and noise could disrupt this. Nor is it surprising that grid-tie inverters create noise or that some are worse than others.
This is guesswork but you could try:-
1. Some large clip-on ferrite cores around the mains cables – quick and quite cheap – look for a kit on Amazon.
2.. Moving the inverters (if in a string) to see what (if anything) changes and (maybe) weed out a “bad apple”. If you can identify the “worst” one – maybe try putting it at the far end of the string?

My only other thought (and this is a bodge)…
If you can reset in the App. Can you use something like IFTTT (or a free automation app) to automatically reset the “bad” item (toggle off and on again via the App) – say every hour. Not pretty but might be better than losing a whole day of production?

Good luck.
Spenser

Hi, Spenser,
Maybe a Timer-switch between Inverter and AC works well… I will try. Not the best solution, I know…. but works automatically…:-)

Hi, what is the best alternative for the IRF3710? i didnt found any seller in Germany for spareparts 🙁
What can i use?

br hugo

Hallo!
I bought me a WVC600 and was impressed about the technical Features. But now I have noticed, that the Inverter doesnt work propperly. In the Morning, when it is getting sunny, the panels are producing only about 30 Watts. The Blue light ont the front of the Inverter is continuous on. No flickering. If I reset the unit, it will emediately produce 200-250 Watts with the same sunshine as before. What can I do? Maybe shut off the Inverter at night? The Unit is only working for 3 days now. Best wishes!

Hallo Martin
I have exactly the same problem, it produces 30-40W and after a restart – maybe 1 minute later at the same sun-conditions – there are about 250W.
Did you find a solution?
Best wishes!

Hi Chris! As I could see in the evaluations of the seller, there is another buyer with the same problem… but several with no problems at all… did we only had bad luck?
I wrote to the seller and described my problem. I shall wait untill they respond… maybe there is a solution. The last days allways the same behavior of the inverter. I can maybe solve my problem temporarely by switching the unit with a timer-switch every morning… and switch off the unit at night. Good luck!

Hello, Chris!
I try this: in the evening, I switch off the unit and start it again at 10:00… maybe by Timer-switch in the future, but now manually. Maybe that works…bad solution, I know. 🙁

Hi Guys,
Rune (above) seemed to find that he could reset and restore full generation simply by using the Cloud Intelligence App. If so you can probably automate this with something like IFTTT (or a free automation app) – possibly easier and more versatile than installing time switches? See my post below Rune.

I still think “noise” could be the culprit. I’d be interested to learn if your mains is 110V or 220V? I would expect 110V to be a lot worse (I’ve not seen the issue with 240V we have in the UK). I know you can’t do anything about the voltage but it might be useful to characterise the problem further.

Good Luck,
Kind Regards,
Spenser

Hi Spenser,
We have 240V too. Today I tried out something new: I switched on the unit, when the sun was allready shining… The inverter was „hooking“ at 70W instead of 40W as before. When I did a reset, the Output was 250W emediately… I am so tired…. Thats no fun!

Hy Martin
Thank you for your answer.
I also had the problem that the WVC600 – when it runs – produces 80-90 watts at a sunny day, after a restart it instantly produces 240 watts. The problems are not only in the morning, but also during the (sunny) day.
My seller told me that the WVC600 needs panels with VOC of about 40-42 volts and VMP of minimum 33 volts to run. My panels only have VOC of 39 volts and VMP of 32 volts… Now I bought anoter microinverter, I am not happy with the WVC600, the specification-sheet is absolutely false (VOC 30-60).
Best wishes
Chris

Spenser, Thank you for the comment,

In my tests I have only one Inverter, not several in a string.
I have 230V, and delivery from GRID is very stable without know noise. I lack the equipment to really confirm it, but no sign of it either.

That I also see is that on most days it is not needed to flip the power switch. It is enough to adjust the power output say from 100% down to 80% and Back to 100% in the app.

The App got the “local timer” setting, so I tested with several turn off/on schedule every hour. However Clouds doesn’t follow the clock so it did only help on days starting with clouds and stable light condition afterward. – As soon as the rappid change cloud,sun,cloud,sun days you must flip the power every minute to get the production run.

It is easy to see the issue in the app, – Just watch the Voltage on the Solar Side. As soon as I see it starts to climb above 32-33v flip the power output down a bit eg. 80% and back to 100% (or the power switch).

I started to think about using a CT clamp or some other DYI to monitor the voltage, and do an home automation to flip the power on it. But I swapped the inverter to a different brand before I spent more money on trying to fix the broked thing.

Hi Rune,
Thanks for the feedback – from your description it sounds like a software (firmware) bug – possibly starting to output at below MPPT voltage then failing to get out of the loop. Oh well, at least you have a solution. I’d be interested to learn. what brand you bought?
I’m currently playing with batteries (small ones) and have bought a 300W Y&H unit or this. Also Chinese – no idea (yet) if they are any good although it will not be in direct sun and will have a fan on it.
I now have all the bits to repair my WVC1600 – just haven’t got around to it yet – I will update when I do.
Good luck one and all.
Kind Regards,
Spenser

bought one WVC600 LIFE it is connected to a 350w 60-120cell panel and the blue light keeps flashing.. I don’t know what to do. advice please.
I also never connected to any internet.. is this necessary?

Hi Gregoris, Yes, you have to install the cloud app, scan the QR code on the inverter or add it as a Bluetooth device. Then create Cloud account and then you access the inverter. You really have to do it to make it work by resetting and changing power to 100% – daily. Pls see my comments further down.

Hi, I realize that this Inverter is not the best quality product among inverters. I have spent ~2 weeks trying to figure out what is wrong, and I also watched a few Youtube videos about MVC-600 Issues.
The issues I see are:
1. When powered up, it often starts in “low power mode” – 5% Power setting. I waited for minutes/hours to see if it would jump to 100% automatically, but not yet seen it. I must always set 100% manually even though the App says 100% – it is not! This means that many customers out there do not get maximum energy out of this product. I must select a lower than 100% setting, go back to main, and then into the setup and select 100% and back. Then it works – for a while, for sooner or later it will revert to 5%! Frustrating and makes me spend time every day to make this work.
2. The next issue is that the voltage the App reads is 7-10V higher voltage than I see when measuring it using my DVM.
Reading (app) 27V, the real voltage is 18V. (DVM)
Reading 44V, the real voltage is 36V.
Seems they add ~8-9V (it is not a scaling factor/%) as the diff V is close to the same whatever voltage output is. This makes the product to appear to have a much higher quality than it has.
– This cause again the real total power to be much lower than the App says.
– Current App data: PV Voltage: 38.6 x Current: 16.3A= PV Power: 628W.
– Real/measured: PV Voltage: 28.9V x 16.7A (app) = 482.6W.
– Conclusion: 482.6/628= 77% of what the App claims!!
3.
I connected the +/- cable to the inverter input so I could monitor the Inverter from my office, and I can see high-frequency noise (18uSec)- 55.55kHz transients that are close to 20V (40Vpp). I am not sure what this looks like inside the Inverter but could be insufficient LP filtering before the AD converter reads the voltage causing the voltage level to be much higher than the real measured voltage. That could explain the constant voltage diff between the app and my DVM reading. I can also see on the oscilloscope a 100X higher freq. oscillation – 0.18uSec (5.55MHz).

4. I have sent multiple Feedbacks through the App and a few days later there was an App update but it did not solve any of my findings. My recommendations were:
– Correct the Voltage reading to display the actual DC Voltage (add a filter – HW or FW).
– Every time user opens the App: Read the Power setting in the APP, compare the Power setting in the Device FW and send a new “Power level” to the Inverter if not equal.
– After “hard reset” (power off unplugging it from the wall), it should as default start at 100% and not 5%.

I will not buy another one until these issues are solved.

..more: Also the App displayed output voltage is 8-10V higher than the real measured voltage.
APP: 238Vac
DVM: 230Vac
If it was a scaling issue the AC voltage diff should have been higher, but it is almost identical to the PV voltage difference. Is this done (Adding a delta V in FW) to show a higher output power than real in order to “protect” the Transistors against overheating? Earlier versions of the Inverter had a Transistor overheating issue. Instead of solving the cooling issue, it was easier to “tune” the FW?

hello from france, any way(picture or how to) to reach the wvc700w lite app ac’s mosfet ?
it seems that it the most common fail of that poor device.
tx

I bought 3 wvc inverters on AliExpress, but within half a year some electronic parts burned out, and all inverters have stopped working.
So, I came to this forum…

I’ve done some repairs, but I’m thinking of giving up on the wvc inverter and switching to another model.

Could you tell me if you have any recommended microinverters that have been in operation for many years?

Hallo, hat jemand einen Dorf Micro Inverter? der scheint von der Bauform identisch zu sein…hab den über estarpower.com bestellt…leider sind die Mc4 connector beschädigt und kann den nicht anschließen…kann man diese problemlos austauschen? bin gerade dabei eine Rückerstattung zu bekommen…

Hi, semiconductors will fail at too high voltage, current or temperature. I found the inverter to be hot even at this time of the year so I bought a small solar panel (5-10W), a 5V 80x80mm fan and placed it under the Inverter too cool it.
(Should have been possible to upload pictures here).

Bugs (App and FW):
1. Make sure that the Inverter always has the required Power setting % as the user has defined it. The current version displays a 100% value, but it can be set to a lower in the FW “Power” parameter value. Add a function where App requests the current Power setting in FW and updates if it does not correspond to the App setting. The default should be 100%

2. Correct PV Panel and AC Voltage values – they are too high (PV: 7-9V) (offset) and display a too high Power, both Panel input and 230V AC output (30V too high). This makes the Inverter to be more efficient than it is.
• This cause again the real total power to be much lower than the App says.
• Current App data: PV Voltage: 38.6 x Current: 16.3A= PV Power: 628W.
• Real/measured: PV Voltage: 28.9V x 16.7A (app) = 482.6W.
• Conclusion: 482.6/628= 77% of what the App claims!!

3. Does the Inverter appear to start going active ?? Or not – just pull the current and lower the Panel output voltage,— but the Currents are still 0A. Cannot see the 50Hz wave – only the 100Hz signal.

4. Tried to solve the low power starting issue (after bigger clouds blocked the sun), causing the Inverter to be set to very low power mode >1%, by activating the Timer as it seems a power on/off cycle makes the inverter start again. I set the timer to turn off at 06:00 and on again at 06:01, same at 08:00, 10:00, aso, but the max number of activations is 10 and too low to make this go for 24 hours.
The next issue is a bug not saving the Timer setting and after the Inverter restart, all settings are gone!
The solution is sad enough – buy a simple power timer and set a short off/on the action every hour or so.
The product makes me so upset, punishment for buying cheap low quality products!

Bugs summary:
1. PV voltage is 8-10V higher than actual and AC output is sometimes 25-30V too high (have seen 270V! but oft 238V when actual is 230V), causing higher power calculation than real input and output power. It does not deliver 600W, but closer to 500W.
2. The inverter does not start after the sun is interrupted by passing clouds and can be solved by:
a. Select “Settings” and alter the Power output %
b. Toggle Inverter On/Off button
c. An alternative could have been to set the “Timer” to turn OFF/ON for a minute every hour or second hour. Unfortunately, this does not work on the current SW version and the setting is not saved. Seems it does for a few minutes, but after checking it later all settings are gone, but I cannot observe it turns the power OFF/ON. Concl.: The timer does not work!
The only working alternative to doing this is to buy a cheap Power switch timer device to interrupt the AC power to the Inverter
3. Annoying GUI design has one button that has three functions: “Setting”, “Energy Clear”, and “Complete”. I have accidentally so many times pushed twice when the App is lagging for a sec or two and then all accumulated Energi gets deleted! Please move the “Energy Clear” to another separate button!
4. New observation: Seems there is a new App update (was 3.16.x) and now it is 3.17.2. The problem is they do not tell us when they make an update, and FW is always the latest FW, and no update available. They should add a message when they update and also display the actual FW version as they do for the App SW.

Good news: It appears the 3.17.2 App version made a change – the Inverter does not have to be turned off/on as for days it is always running at 100% power output. I have sent > 10 Feedback regarding App and FW, but there is no history found in the App. It is still a way to go here to make this into a professional product.

I must correct the “Good news” statement above as the inverter still has this low-power mode issue. Here are the bugs that remain and to be aware of:
1. Every time a cloud covers the sun you must open the app again when the sky is blue and check the Power value in the App. If it is less than 150W, go to settings and either turn power off and on again or select a lower power setting (75%) and then back to 100%. Check if it jumps up to >300W (if the sky is blue). If not – repeat. I have observed that changing the power level does not always work but turning the inverter off, waiting 5 sec, then on again. Just try it. One solution could be to buy an electronic on/off timer and program it to turn and disconnect the Inverter (230V) for one minute every ~30? minutes to run this somewhat automatically.
2. Both PV and AC voltages are often too high – 10-20V. It fluctuates depending on the PV voltage waveform. Not sure what kind of LP filter they designed for voltage and current fed to the A/D converter. I have seen AC voltage at 268V!! It was ~240V. Sure this gives incorrect output efficiency %.
3. The “Local Timer” table in the app can be programmed with up to 10 diff on/off time settings, but after a few minutes, all timer settings get deleted.
4. Lately I have observed that both PV and AC current is 0.00A. Comes and goes sometimes – thermal/solder issue or FW bug?
5. The “Total Energy kWh”, “Emission reduction” and “Planting trees” value in the app gets cleared – set to 0 now and then, often after a day or two.
Solution: Buy an Energy adapter with a WiFi interface or LCD panel to monitor actual and accumulated Energy saved – the App is useless for this!
6. I asked them to make a new button for “Energy Clear” to avoid accidentally pushing the “Settings” button twice. There is no warning popping up if I really want to do this and asking me to confirm!
7. It seems the HW is working OK and after adding a solar panel-powered 5V fan under it I hope this will increase the lifetime and prevent overheating.
8. It is upsetting that a product, most likely sold in huge quanta, has so many quality issues. I have spent > 50 hours trying to find workarounds and sent them probably more than 20 Bug reports, it could be App version increased from 3.16 to 3.17.2 after one of my first feedback reports, but what is done with the FW I do not know as I cannot find what version is the actual one.
9. Just to add, this morning the “Output Power” was 1164.4W (“PV Power” 175.1W). This is not a big issue; it just says something about the code quality. It is a simple code that just reads the A/D converter, but does not check if it is inside allowed min/max values and call for a re-read.
10. If they come up with SW/FW fixes I will investigate Hoymiles or AP System Inverters. Does anyone have experience using these?

I have model WVC 600 can I request schematic diagram ?
Requesting in my email or can share in this group have also.
God bless

Very poor product!
I have WVC-1600 bought from Ali-Express. However PCB inside says WVC-1400!
Manufacturer, Ali-Express & supplier are all totally useless.
Was working OK for a couple of months, but now it resets itself every 10-30 seconds. The MPPT steps up increasing power with flashing blue light then suddenly stops generating and red light comes on, just keeps repeating this loop. FETs all seem OK and generates power OK until it resets. Internal 12 & 5V rails all look clean and stable on oscilloscope. All seems to be controlled by PIC16LF1939, but i cant see the stimulus for the reset? odd…
Anybody seen this before?
Anyone have any schematics which may help?

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