Hi, 

I have a Kool Energy 1.5kw 24v inverter working on 2x 12v 100ah gel batteries in series. The inverter was not in use for about 5 months and when it was turned on some of the mosfet transistors popped. I have taken the board in for repairs to a local electronic repairer and he replaced all the transistors(MT06N008A) with a substitute part transistor(FTP08N06A). When I switch the inverter on it runs on the mains(220v), but the moment the mains goes off and it goes into battery mode the inverter displays Error code E02 and switches off shortly after. Error code 02= "Output short circuit" according to the manual. On visual inspecting the board I cannot see other components with clear damage. Is the replacement transistor adequate for a substitution? Battery terminals  and connections are all the same as it came from the factory. I will greatly appreciate any input,

 

Regards

Helgard 

Hi Helgard

Did you ever get an answer to your problem ?

I have the same issue after having all mosfets replaced with original part number.

Hi Muratech, unfortunately I did not find any solution yet, however I tested further and noticed when I tested the Toroidal transformer through continuity test that there is no resistance, so when it goes to battery mode i get the error code, im struggling to find a replacement transformer, but if i get a solution I will give you an update. 

Hallo Bkade77, have you taken the Toroidal transformer out of the housing before measuring to have a look and see if there is a diagram on the transformer which indicates which wire is connected where on the windings of the transformer?

Transformers rarely open on a winding, they rather burn out than open on a winding.

Hi Gerhard, thanks for the response, I have not removed the transformer,it's disconnected from the circuit though and I have not tested the primary or secondary windings etc, I only tested the live and neutral cable that is connected to the transformer and it tested almost 0 ohms, I will remove it out and see as you are suggesting, I heard it's quite rare for it to be the problem, thanks for the feedback ,🙏

Hi all, have you found any resolution to the issue you are faced with, have the same problem about the MOSFETs that have popped. I believe that other components also have problems. This can be regarded as a switchmode power supply and the MOSFETs are dependent on other components to operate correctly. If it is faulty or out of range it will not operate correctly. In my case, I found some of the surface mount components that have also burned (believe it is the driver circuit to the MOSFETs). My solution would be to source the whole board, I am busy searching for it. If there is anyone that has found it please share, I managed to find the 2.0 version board in the Philippines but there is no option to ship to SA, and out of stock. To repair the card you will require quite advanced knowledge and experience on the circuit and electronics. 

@Joachim du Plessis Is this for a Axpert inverter. I have bought a Mainboard board for a 5kW inverter from the Sunpays. They used to have stock. They also sell 2nd hand inverters at a fair price.

Hi Chris, it is for a Kool Energy trolley, the board is made by Snadi Snat, will follow up with Sunpays, thanks for the advice!

 

 

20 hours ago, Joachim du Plessis said:

Hi Chris, it is for a Kool Energy trolley, the board is made by Snadi Snat, will follow up with Sunpays, thanks for the advice!

 

 

Called numerous suppliers, this card is not easy to get.

Hi Everyone

Check all the 10 ohm gate driver resistors in front of the mosfets (and inbetween the heatsinks). You can use a multimeter to test them on the board. Normally some of these resistors blow when the mosfets blow. Also see the picture attached. The group of PNP & NPN transistors circled in red (marked 2F & 1P) almost always blows a few when the mosfets go. I'd guess thats where the problem lies. The 220uF 25V cap & zener diode (marked N4) circled in yellow also like popping at the same time. You can test all those diodes & transistors around that area on the board (below the red circle) with a diode tester / multitester once again. If any are shorted, replace them. Hope my two cents help.

On 2024/04/02 at 1:46 PM, NathanL said:

Hi Everyone

Check all the 10 ohm gate driver resistors in front of the mosfets (and inbetween the heatsinks). You can use a multimeter to test them on the board. Normally some of these resistors blow when the mosfets blow. Also see the picture attached. The group of PNP & NPN transistors circled in red (marked 2F & 1P) almost always blows a few when the mosfets go. I'd guess thats where the problem lies. The 220uF 25V cap & zener diode (marked N4) circled in yellow also like popping at the same time. You can test all those diodes & transistors around that area on the board (below the red circle) with a diode tester / multitester once again. If any are shorted, replace them. Hope my two cents help.

Hi nathan do you possibly know of any alternative mosfets for the above board cant find any and what if you know the part part numbers for the pnp and npn transistors 

thanks