1 hour ago, plonkster said:

 

The others appears to be made by Texas Instruments. Can't find a datasheet for them.

csd19505kcs.pdf

4 minutes ago, Chris Hobson said:

csd19505kcs.pdf

Thanks Chris. So it is a MOSFET then.

I wonder if there is a way to test the ESR of those caps? Well, of course there is, you probably stick an AC signal to them and check how much current they pass, I mean, it would be good if we could verify that it's the caps that let down the FETs.

Best change of getting it repaired might actually be to ask them Ausies to do it :-)

Only 10V Vgs... that's not bad at all. Well, it certainly makes life easier for the driving circuit. Some of these things you have to hit with 20V to get them fully on. For example, the Microcare MPPT uses 15V in their design.

Of course the more important bit is the Rds(on) (Resistance drain to source when on) value.

2 hours ago, Noobie said:

Thanks Chris, much appreciated!

Anyone in JHB who can repair this board so that I have a spare?

Try Asher -he advertised here a couple of months back

Please Call/WhatsApp me on 0786591203.

I'm based in Fourways, Jo'burg.

8 minutes ago, plonkster said:

Thanks Chris. So it is a MOSFET then.

I wonder if there is a way to test the ESR of those caps? Well, of course there is, you probably stick an AC signal to them and check how much current they pass, I mean, it would be good if we could verify that it's the caps that let down the FETs.

Best change of getting it repaired might actually be to ask them Ausies to do it :-)

The Aussies recommend replacing the DC caps with these caps https://www.digikey.com.au/product-detail/en/united-chemi-con/EKZN800ELL182MM40S/565-4129-ND/4843939. The besides the 80V rating the 10000 hrs as  at 105°C is important as opposed to the 63V 2000hr rating of the originals.

The 4 sets of 4 MOSFETs need to be replaced with higher voltage rated ones. The ones that have blown are 80V but @Coulomb and Weber looked at 5 possibilities and eventually plumbed for https://www.digikey.com.au/products/en?keywords=SUP70040E which is rated at 100V. 

 

 

@Chris Hobson @plonkster
Just remember he is using a Axpert 3kva 24v plus - Mecer brand not the 48v so components I suspect won't be the same

2 minutes ago, viper_za said:

@Chris Hobson @plonkster
Just remember he is using a Axpert 3kva 24v plus - Mecer brand not the 48v so components I suspect won't be the same

Well, I could not find the datasheet because I thought it read CS019505kcs (and I swore under my breath because how am I supposed to know if that is a zero or an Oh), and then it turned out to be a D! And the datasheet exists and it is an 80V FET, which I believe is the same one that is used in the 48V version. Of course we can't blame caps and voltage issues if we're really talking about a 24V inverter... (which, technically, is bad news... it means there is another yet as undetermined thing that blows these things up).

1 hour ago, viper_za said:

@Chris Hobson @plonkster
Just remember he is using a Axpert 3kva 24v plus - Mecer brand not the 48v so components I suspect won't be the same

Facepalm  - I did not even consider it was anything else than a 4kW unit. -Pays to look at the signatures that's what they are there for!

3 hours ago, plonkster said:

And the datasheet exists and it is an 80V FET, which I believe is the same one that is used in the 48V version. Of course we can't blame caps and voltage issues if we're really talking about a 24V inverter... (which, technically, is bad news... it means there is another yet as undetermined thing that blows these things up).

I have had a report that the MOSFETs in some of the 24 V models aren't the same as in the 48 V models; they sometimes use Toshiba units with a higher RDSon. Possibly, whatever is available with the appropriate voltage rating. 

I believe that the capacitors can still be to blame, even if the MOSFETs are rated at 80 V. When a capacitor goes high impedance, the voltage spikes can be many times the supply voltage, easily exceeding 80 V when the supply is under 30 V. 

While we are talking about dodgy inverters does anyone have any info on the iPV 5000 (pic attached), it's specs seem remarkably similar to the Axpert MKS 5000 but looks a bit different.

I cant find any info on the web so probably re-branded - I am hoping somebody will recognize the type.

Looks like a clone rather than a re-branded item.

After more than 5 years of experience in installation in the RV industry I can Say despite the very good performance these Victron products provides. They have the worst AC ports in the industry. 

 

Always gives me headaches to work on Them , Kisae provides Much better AC ports and I can't understand why this brand is still producing inverters with this Poor quality ports.