wvc-600 crap

WVC solar micro inverter teardown

Here is the 6th inverter that failed… on a 6 inverters installation!
It has melted, like the number 5. You can find more details about the repair of the number 5 on this blog.

failing wvc-600 melted transformer
failing wvc-600 melted transformer

In the center of the picture, we can see that the precision transformer (in blue) has melted! And it’s not even close to the Mosfets! The specs says that it’s rated at 80°C but can sustain up to 130°C. This means that the wvc-600 inverter, with it’s sealed enclosure and no cooling, runs above 130+C!!!

We can also see that the smps transformer (yellow on the right) is starting to peal off!

Another funny thing: the third smd cap (from the bottom) is smaller than the two others. It should be a 100 uF capacitor, but I guess Kaideng was missing one. So how do you know: they just put a 22uF cap! Who cares, right?

Wvc-600 closup on dead input capacitors
Wvc-600 closup on dead input capacitors

Here is another view of the wvc 600 inverter, showing the dead bulged smelly linking input caps. The rest of it is stuck on the case cover.

But hey, I’m starting to get used to this. After changing the dead capacitors, the input cables, the melted MC4 connectors and the meted transformer, it runs again… What will happen next?

As most of Chinese inverters, and after 6 inverters blown up, I can say with certainty that the specs of the WVC micro inverters are a lie. They cannot sustain 600 Watts. Well, for starter, the efficiency is so bad that with 600W of solar panel, they have never put up more than 500W. But still, I strongly advise not to feed more than 300W, unless you modify them with a proper cooling.

wvc-600 crap

WVC-600 micro inverter repair: number 5

This is a followup about the fifth inverter that stopped working (and melted).

wvc-600 without caps
wvc-600 without caps

After removing the caps, we can see the amount of heat they must have gone through. No wonder why they blew up.

failing wvc-600 burned mosfet
failing wvc-600 burned mosfet

I’ve also desoldered and replaced one of the input mosfets, because it seems much darker than the others.

failing wvc-600 with heated traces
failing wvc-600 with heated AC traces

On this picture, we can see that the AC traces of the circuit board are too thin. They have heated up and started to burn.

WVC-600 strengthened circuit board traces
WVC-600 strengthened circuit board traces

So I’ve added to copper wires and solder to the AC traces on the back of the circuit, and to the Mosfets traces as well.

WVC-600 repair capacitors
WVC-600 new capacitors

Here is a view of the inverter with new branded low esr caps (Nippon Chemi-Con). They are ten millimeters taller, so I had to put some spacers between the case and the fan.

wvc-600 air cooling mod
wvc-600 air cooling mod

Here is the finish repair and mod of the fifth wvc 600 solar micro inverter, with the burn parts removed and replaced: input capacitor capacitors and connectors.

wvc-600 mod holes for air cooling
wvc-600 mod: holes for air cooling

Now it’s back in production and runs fine, apart the “MPPT stuck” problem that I still have to figure out, and the efficiency that is still crap. The temperature goes up to 31°C with two 300W pannels, compared to 45°C with only one panel before… and much more than 100°C with two panels!

wvc-600 crap

WVC-600 micro inverters have defective MPPT

The MPPT has been working erratically since day one. I’m monitoring the solar energy production on my home automation system and here is an example:

wvc-600’s crappy MPPT

As we can see on this graph, the production stays stuck at around 200W… until I shut down the AC and turn it back on. Otherwise, the wvc-600 production stays at 200W all day long. With a total of 3600W solar panels, that’s not much. At least they wont overheat!!!

And it didn’t happened just once, but the problem arise regularly:

wvc micro inverter failing MPPT again
WVC grid tie inverter MPPT stuck

I’ve contacted the manufacturer, Dongguan KaiDeng Energy Technology Co, but they’ve never replied.

This shows how unreliable the WVC micro inverters are, and the lack of support.

wvc-600 crap

It’s sold on Amazon! Y&H WGTI-600W-230V

This total crap wvc-600 is sold on Amazon… by Amazon!
It’s re-branded Y&H, whatever that means. Oh wait, it means Yong Hui…

Amazon re-branded wvc-600 solar micro inverter

EAN: 0706973497334
UPC: 706973497334
Model: WGTI-600W-230V
But it’s the same shit. At least they have accepted my review.

Crazy wvc-600 connection to the grid.

Yes, the pictures in the Amazon description tells a lot about the product. If you want to burn your house, just follow the instructions 😉

More seriously: DO NOT CONNECT YOUR INVERTER LIKE THIS!!! (and do not buy that shit in the first place)
You need a differential circuit breaker at least, surge protection and so on.

wvc-600 crap

Solar micro inverter: totally fried

I’ve finally opened one of my melted inverters. I call it “number 5” because it’s the fifth one to fail, over 6 inverters. The exact model is WVC-600W.
This one at least has been running for a year or so. This is not bad considering that two wvc-600 have stopped working after only one day of use.

wvc-600 blown caps, melted connectors…

With two 300W solar pannels, the inverter has been running so hot that the conformal coating evaporated and then condensed everywhere… you can see the droplets on the cables.
The PCB has been bent by the heat, the MC4 connectors have melted.

wvc600 dead caps

When opening the case, part of the caps stayed stuck to the lid.
The capacitors are rated at 105°C, but the wvc inverter has been running much hotter than this, which is not surprising because it’s completely sealed with no active cooling.

Melted solar panels connectors on wvc-600

I only have 4 inverters working now, with only 4 panels to avoid overheating. So about 700 Watts produced for an installation of 3600 Watts.

As I have wasted a lot of money in these Chinese crap, I will try to repair this one. I’ve ordered branded low esr caps and genuine Mosfets with low rds(on) to reduce the heating, and I also plan to make an active cooling of some sort.

wvc-600 crap

Two wvc-600 inverters melted

Two days ago was very hot over here, more than 34°C. The circuit breakers tripped again.

Two of my six active wvc-600 inverters literally melted!

Melted connectors on wvc-600

What do you expect: they have no active cooling, the enclosures are completely sealed. They are running so hot that 30 minutes after shut down I still couldn’t hold them in my hand!

You can see the traces of the sparks the wires did when touching the frame. It could easily have taken fire.

This is now the 4th and 5th inverters that fails, after 15 month of use, on a 6 inverters installation.