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.

48 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 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

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