Repair of Axpert Inverters : A Journey Started

[ChristoSnake]

You're welcome to take your time to get acquainted with that beast of an inverter...

It may also be worthwhile to reach out to @Youda.  He has a <insert appropriate collective noun> of InfiniSolar 5kW inverters and seems to know their workings inside & out.

PS: I'll bring a smaller vehicle next time

[ChristoSnake]

23 hours ago, BritishRacingGreen said:

Interestingly , the high voltage DC bus caps are not on the main board , but separate cluster of capacitors. I would like to know why there are so many ( i think there is  6 or 8  large 470uF 500V caps).

Could it be related to this model's 900V PV limit?  I ran it with two strings of 12S panels each, somewhere around 500V on each of the MPPTs most of the time...

[BritishRacingGreen]

31 minutes ago, ChristoSnake said:

You're welcome to take your time to get acquainted with that beast of an inverter...

It may also be worthwhile to reach out to @Youda.  He has a <insert appropriate collective noun> of InfiniSolar 5kW inverters and seems to know their workings inside & out.

PS: I'll bring a smaller vehicle next time

[BritishRacingGreen]

26 minutes ago, ChristoSnake said:

Could it be related to this model's 900V PV limit?  I ran it with two strings of 12S panels each, somewhere around 500V on each of the MPPTs most of the time...

It may very well be. The cluster of caps sit upstairs and connected to somewhere on the bottom compartment. That compartment houses, amongst other, the main board which consist of the MPPT and the DC-AC converter. 

I am going to dissasemble on thursday after taking some detailed snapshots of the interboard wiring. We shall know by then. 

[BritishRacingGreen]

Below is an extract from 10kW Infini manual :

 

 

Very interesting to note that the Infini measures and detect earth leakage from the PV internally.  Is this a feature on gridtie , and if so why is it particularly  important , or otherwise why is it not important for the offgrid Axperts?

 

EDIT : I regard this as important personally , so I have my MAX7.2 grid feed after the upstream main db board ELD. So I like to be informed of leakages in the inverter itself. I do get trips on rainy weather by the way , which indicates leakage from my panels or panel feeds. Its irritating , but the ELD tells me a lot about the healthiness regarding leakage. 

Edited April 19, 2023 by BritishRacingGreen

[Coulomb]

4 hours ago, BritishRacingGreen said:

Very interesting to note that the Infini measures and detect earth leakage from the PV internally.  Is this a feature on grid-tie ,

I believe so, yes.

4 hours ago, BritishRacingGreen said:

and if so why is it particularly  important ,

I think it's because the leakage could lead to various problems, some inverter related (e.g. Axperts are prone to bus over-voltage caused by leakage), but also safety issues. I don't fully understand the detail.

Certainly on-grid inverters are subject to a whole lot more regulation and certification than off-grid inverters.

4 hours ago, BritishRacingGreen said:

or otherwise why is it not important for the offgrid Axperts?

I actually think it IS important for off-grid models like Axperts; for a few dollars more, they should include it. And that makes the Axpert high voltage PV models unsafe in my opinion. There have been reports on this forum of people getting minor shocks from tin roofs and the like; I'm surprised that no-one has been seriously injured.

Edited April 19, 2023 by Coulomb

[BritishRacingGreen]

37 minutes ago, Coulomb said:

And that makes the high voltage PV models unsafe in my opinion

Makes sense too me as well,. 

[Richyv]

On 2023/04/10 at 8:29 PM, BritishRacingGreen said:

Update on @Richyv inverter failure. As expected, its the dry capacitor on the 5V regulator input (1000uF 16v).  The esr of 1000uF  on the 12v rail suggest he would been the next to fail. As per esr, no other electrolytic suggest there is imminent failure. This is typical of all 6 machines i have serviced so far. 

Interestingly, the failed caps have been of different makes, and the machhines have been of different brands (rct and mecer)) , so the degrading of esr I can only attribute to ripple current, especially in the case of the 5v rail cap. In the case of the 12v, the operating voltage is also  too close to 16v rating.  Temperature does play a role, of course, but it is a common mode factor, which should affect all electrolytics in close proximity equally. 

Owners of MK2 axperts that has been in service for 5 years or longer, brace yourselves. But good news is the fix is not a major one.  

EDIT: a question that has been posed is wether one should proactively upgrade non compliant (esr) caps  per these models, while the machine is still good. I dont think so, the failure mode does not cause secondary damage, although the symptoms are scary. Fortunately the DSP fails during its startup phase where it start enabling its power to on-cpu subsystems. That increase causes the 5V to sag, so everything else related to the main board is pretty dormant and no harm affected. Or at least thats my theory. Havent had additional failures except the 5V rail failure. 

EDIT :  of course, further to above, one must also take in consideration that the very first failure is actually when the machine is on and delivering power, and the DSP cuts off abruptly. That is ungracefull and could probably lead to igbt / mosfet failure. But this does not seem to happen, insofar the machines I had serrviced. 

 

 

 

Huge thank you @BritishRacingGreen for helping me out with the repair. It’s now been in for two weeks and working better than ever. You sir are a gentleman and a scholar! 

[BritishRacingGreen]

23 hours ago, Richyv said:

Huge thank you @BritishRacingGreen for helping me out with the repair. It’s now been in for two weeks and working better than ever. You sir are a gentleman and a scholar! 

Thanks Richy thats kind of you. Good to meet you, keep in touch here on forum. 

[BritishRacingGreen]

I have a nasty solar related problem , but an interesting one also. I passed on my old MKS3 (only 2 years old though) to my son-in-law , he added a Pylon UP5000 and used it as a backup system for a couple of months. Last week we added 4x555W panels to the mix (one string supply (170-180V  working voltage) .

I encountered a nasty failure mode in that the  PV will supply high loads or charge flat battery without any problems . When the PV demand is in the order of 1kw and higher , no problem. But when the load is only like 300watts and the battery is full, then the system becomes unstable . The battery voltage rise slightly , and of course affects a large charge current from the MPPT . when that happens , the PV drops again , and everything repeats at about 3 second interval. Add a large load , hairdryer at 1.5kw , everything is stable again. or add a flat battery , everything is stable again. weird. What worries me is that sometimes the AC output also fluctuates somewhat.

The MKS3 MPPT was just working fine when I decommissioned it at my own site.

So here is my theory . I think the MPPT regulation is faulty . I have seen it on the DC bus voltage curve on the HomeAssistant log. So when there is no load on the MPPT , the DC bus shoots up .  But when there is load , the regulation improves for the wrong reason , dampening the rise in DC bus voltage. Could be a faulty MPPT current sensor , I am taking wild guesses. 

There are suggestions it may be a panel related issue , but I have my doubts . When a panel is weak , or we have dry joints in the PV cables , we would experience just about the opposite  behavior as described above .

Fortunately , courtesy of our dear friend   @Steve87 ,  I have an MKS4 which I am going to test tomorrow at son-in-law site , in order to make sure in what subsystem of the installation the fault lies , panels or inverter .

So I will keep posted on my findings . One thing I have learned , is that my PV  commissioning procedure must be revisited in order to ensure that  PV operates adequately at various load conditions.

The interesting thing is that no error is offered , I think the poor regulation  is still within the DSP's windows of forgiveness , otherwise it would have raised a DC voltage too high error or so.

I hope its hardware  related and not require firmware upgrade . I am sh#t scared of firmware upgrade , so far I had no need to touch that , it makes me wake up at 3 in the morning , eyes wide open. Then I realize we have a mentor in @Coulomb , nightmare is over and I fall asleep again. 

 

 

 

 

Edited April 27, 2023 by BritishRacingGreen

[Scorp007]

4 hours ago, BritishRacingGreen said:

I have a nasty solar related problem , but an interesting one also. I passed on my old MKS3 (only 2 years old though) to my son-in-law , he added a Pylon UP5000 and used it as a backup system for a couple of months. Last week we added 4x555W panels to the mix (one string supply (170-180V  working voltage) .

I encountered a nasty failure mode in that the  PV will supply high loads or charge flat battery without any problems . When the PV demand is in the order of 1kw and higher , no problem. But when the load is only like 300watts and the battery is full, then the system becomes unstable . The battery voltage rise slightly , and of course affects a large charge current from the MPPT . when that happens , the PV drops again , and everything repeats at about 3 second interval. Add a large load , hairdryer at 1.5kw , everything is stable again. or add a flat battery , everything is stable again. weird. What worries me is that sometimes the AC output also fluctuates somewhat.

The MKS3 MPPT was just working fine when I decommissioned it at my own site.

So here is my theory . I think the MPPT regulation is faulty . I have seen it on the DC bus voltage curve on the HomeAssistant log. So when there is no load on the MPPT , the DC bus shoots up .  But when there is load , the regulation improves for the wrong reason , dampening the rise in DC bus voltage. Could be a faulty MPPT current sensor , I am taking wild guesses. 

There are suggestions it may be a panel related issue , but I have my doubts . When a panel is weak , or we have dry joints in the PV cables , we would experience just about the opposite  behavior as described above .

Fortunately , courtesy of our dear friend   @Steve87 ,  I have an MKS4 which I am going to test tomorrow at son-in-law site , in order to make sure in what subsystem of the installation the fault lies , panels or inverter .

So I will keep posted on my findings . One thing I have learned , is that my PV  commissioning procedure must be revisited in order to ensure that  PV operates adequately at various load conditions.

The interesting thing is that no error is offered , I think the poor regulation  is still within the DSP's windows of forgiveness , otherwise it would have raised a DC voltage too high error or so.

I hope its hardware  related and not require firmware upgrade . I am sh#t scared of firmware upgrade , so far I had no need to touch that , it makes me wake up at 3 in the morning , eyes wide open. Then I realize we have a mentor in @Coulomb , nightmare is over and I fall asleep again. 

 

Thanks for sharing so that we can tap into your left side of the brain.

[Coulomb]

7 hours ago, BritishRacingGreen said:

Last week we added 4x555W panels to the mix (one string supply (170-180V  working voltage) .

That seems on the low side. I wonder if with one more panel it would regulate a whole lot better.

The other thing is, is it really broken? Does anything get out of specification? You mentioned AC output voltage fluctuation; how much does it fluctuate? It can certainly be annoying of lights flicker.

[BritishRacingGreen]

18 hours ago, Coulomb said:

That seems on the low side. I wonder if with one more panel it would regulate a whole lot better.

The other thing is, is it really broken? Does anything get out of specification? You mentioned AC output voltage fluctuation; how much does it fluctuate? It can certainly be annoying of lights flicker.

@Coulomb , you may be right on both counts , sir !    I have only a reference of sites that draw some 1kw or higher at day time (pool pump is on during sunny hours eg.) , so I cannot yet say that the current  behavior is out of specification , there is very little load to offer . The fluctuating AC was at a time when the inverter was battery less, so lets count that out of the equation for the time being. Also , the so called fluctuating battery voltage that I claimed , was due to PV drop where battery added the extra energy when grid not available , so a small charge was affected when the pv came strong again. 

It was load shedding exactly when I was onsite , sigh, so I couldn't perform additional ac blending test ,but my son-in-law will have logs ready for me in good time .

I have introduced an MKS4 this morning , same behavior !. I did a tentative inspection on joints etc on the roof and couldn't fault anything.

So the MK4 is still operating , I took the MKS3 home . I have a string of 5 panels (210V) that I can easily downgrade to 4 panels to masquerade the remote site at home . Hopefully I will find time over the weekend , else during the week.

So we learn until the day we go on retirement. ..... oh wait ....... I am already retired 

 

Edited April 28, 2023 by BritishRacingGreen

[BritishRacingGreen]

Hi @Coulomb, when an MKS2 inverter is flashing an error code, say 03, but the display is alternatively flashing between 03 and HS, does that mean the inverter is actually configured for parralel  working?

The reason why i am asking is because this particular inverter is standalone (single), and I am wondering if a standalone inverter that is configured for PAR mode will produce unwanted side effects or even be the cause of errors.

EDIT: unfortunately I do not have access to the machine, yet, to check what option 28 is. 

 

Edited May 3, 2023 by BritishRacingGreen

[Akif]

On 2023/01/28 at 10:07 AM, BritishRacingGreen said:

REPAIR : 4 x RCT MKS2  Inverters Received from Malawi

Went to receive the boxes from Alrode destination  as fast as my feet could fly.  I will refer to the inverters as MR1,MR2,MR3 and MR4 . MR1 and MR2 had been paired as parallel units  in a single location , MR2 and MR3 also paired but different location.

 

The initial bringing up of the inverters done by current limited dc source on battery.

MR4 :  error code 09 . That's nasty , indicates IGBT and/or MOSFETS blown , but great opportunity for me  to show my experienced gained in this regard

 

Below is short video showing the symptoms of MR1, MR2. 

 

 

MR1,MR2 :  You cannot believe this . Exact same problem as the previous Cape Town machine. Frequent clicking sound . Couldn't resist the temptation . Immediately disassembled , and powered the main board and control board standalone. Exact same  problem . The input electrolytic capacitor on  U5 (5V regulator) has given up on life. Temporary soldered on a 470uF and problem solved.  Two exact machines in same location , same symptons , same remedy , crazy is it not !  Main boards marked 2015 .

MR3 :  This one has a major problem as far as I am concerned : it has no problem at all. So here comes the start of an issue regarding quantative  vs qualitative  measures.  So if we cannot quantify an error , we will have to use qualitative measures to ensure this inverter is good for a number of years ahead, and that we can dispatch back to Malawi with a calculated measure of confidence . This also holds true really for MR1,MR2 and MR4. 

So all in all all four inverters appears to be serviceable and I am looking forward to start with MR4 and document the findings and repair.

  

 

So wanted to say a huge thank you to @BritishRacingGreen for coming to my rescue and reviving 3 of the 4 Axpert inverters that I had sent to him. 

Boy oh boy am I glad I got in touch with him as I was given some serious doom and gloom stories from a solar dealer in Malawi that the boards on all the inverters were fried and they could only be repaired by changing these at a great cost! I did my own research and contacted @BritishRacingGreenwho was an absolute scholar and gentleman and has been amazing in this journey and gave me some sound advice whilst he repaired them. 

Happy to say the 3 are back home now and been up and running for the last couple of weeks and are working perfectly. So glad to have them back. Am sure @BritishRacingGreenwill come up with a plan for the 4th one in due course. 

Thanks again Sir and so glad we met. 

[Coulomb]

3 hours ago, BritishRacingGreen said:

Hi @Coulomb, when an MKS2 inverter is flashing an error code, say 03, but the display is alternatively flashing between 03 and HS, does that mean the inverter is actually configured for parallel  working?

Yes.

3 hours ago, BritishRacingGreen said:

The reason why i am asking is because this particular inverter is standalone (single), and I am wondering if a standalone inverter that is configured for PAR mode will produce unwanted side effects or even be the cause of errors.

In a perfect world, it would not matter. But I vaguely recall some problems that went away when a stand alone machine was configured back to single AC output mode (non parallel). That was some time ago, so maybe newer firmware doesn't suffer from this any more, but I'd definitely want to switch it to single mode first to eliminate any surprises. Especially since MKS II firmware generally isn't particularly recent.

Fault code 03 (battery voltage is too high) might be because of bad calibration, or the usual high value resistors are affected by moisture.

[BritishRacingGreen]

On 2023/05/03 at 5:09 PM, Akif said:

So wanted to say a huge thank you to @BritishRacingGreen for coming to my rescue and reviving 3 of the 4 Axpert inverters that I had sent to him. 

Boy oh boy am I glad I got in touch with him as I was given some serious doom and gloom stories from a solar dealer in Malawi that the boards on all the inverters were fried and they could only be repaired by changing these at a great cost! I did my own research and contacted @BritishRacingGreenwho was an absolute scholar and gentleman and has been amazing in this journey and gave me some sound advice whilst he repaired them. 

Happy to say the 3 are back home now and been up and running for the last couple of weeks and are working perfectly. So glad to have them back. Am sure @BritishRacingGreenwill come up with a plan for the 4th one in due course. 

Thanks again Sir and so glad we met. 

Thank you so much @Akif, I am just glad you had the patience for waiting  the number of weeks I had the machines in my possesion. It was a valuable exersize for me, so thanks once again.

And the 4th has had a terrible surge which destroyed all 9 IGBT including some drivers, but is remains my endeavour to bring it up some time in hopefully not too distant future. 

[BritishRacingGreen]

On 2023/04/17 at 8:43 PM, BritishRacingGreen said:

Enters the Infinisolar Inverter 5kVA Single Phase

I have now entered unknown territory , the Infini series. @ChristoSnake delivered the above model for repair.  Nice guy , good to meet . I think he was aware of Germiston roads being terrible , because he arrived with a larger than life Nissan Patrol , absolutely beautiful vehicle , which amongst other amazing things  , he has done several upgrades.  Offloaded the machine , so this gives us the opportunity to try and learn the inner working of this grid tied beauty. 

After opening the bonnet , I am very impressed with the layout and overall quality. Its slightly offending with its presence  , like the Nissan Patrol , because I am so used to the Axpert by now . But here is the beautiful thing   , one start to relate to the machines subsystems as you expect nothing really out of the ordinary. The analogue power train is as expected , obviously all the intelligence lies with the DSP control board , and the latter looks like a complicated beast just looking at it.  Its even got a slave DSP controller , along with the Master controller, ouch , this is @Coulomb territory  ,big time.

Its a double story layout , with the power supplies (SPS) and DC-DC converter on top . In the basement is the large DSP controller board as well as the DC-AC converter (main board). Now this I love to no ends , the DC-DC  and DC-AC all-in-one on the Axpert , but on Infini  they are modular , separated . Interestingly , the high voltage DC bus caps are not on the main board , but separate cluster of capacitors. I would like to know why there are so many ( i think there is  6 or 8  large 470uF 500V caps).

The SPS is your typical SMPS's 12V , 5V -12V  concentrated from PV, Grid and battery.  The DC-DC converter looks pretty straight forward , 2525 PWM controller . Interestingly there is 2 sections in parallel , each delivering 2.5kW.  The mosfet and igbt drivers also onboard , as expected.

I have disassembled nothing so far . Only thing I have done is I tested for short circuit on the battery side , and low and behold , 0.2 ohms !  . So I will be starting with the DC-DC board , which I am  going to remove as a standalone circuit board.  I will be taking it slowly and easy though , but looking forward to  this part of our repair journey .

Circuit diagrams are non-existent , and I don't think @Coulomb has partial schematics . There exists not even a service manual for the 5KW (I see Coulomb has uploaded a 10kW one , which has given me some insight already). But guess what , these are the rules of engagement , and we will see how the knowledge we have gained from other power trains , will help us here .

 

 

3 weeks down the line, and today its time to investigate @ChristoSnake 5kw Infinsolar inverter. I have measured a dead short across the battery terminals. 

I dissasembled the unit in order to expose the DC-DC converter module and the main board (DC-AC plus MPPT).  Below is an image of the two boards, the main board at the top, and DC-DC board at the bottom. 

There are no documentation regarding this 5kw unit. So I had to figure out the whole DC and AC bus topology before I can even start debugging. 

This was very confusing until I at last realized that this is actual a split phase machine, when configured appropriately will deliver ac on phase S and phase R. That explains why we have two identical dc-dc converters as can be seen in the image.  They generate two seperate HV dc busses called BUS- and BUS+. And  they are tied together on the main board to the N (AC neatral). Because the DC bus is really now a split supply bus with negative and positive sources with reference to N, the AC-DC converters on the mainboard can now merely entertain a half-bridge IGBT arrangement to produce AC. But there are two supplies, so there are 2 half-bridges, one for S phase and one for R phase. 

BUT this machine is not configured for split phase, so it is my assumption that the DSP generates the two phases at exactly 0 degree difference (as oppose to 180 for split phase). Then the hardware combines the S and R phases on the AC output board. And yes I have measured a short on this board. 

MPPT follows suit by also generating a split supply. 

So this is actually now two 2.5kW inverters  running in parrallel within the same maxhine. This of course is a gross overkill. This 5kW machine has more heatsinks and power silicon  than a MAX 10kW.  Definately more silcon then Pamela Anderson had back in the day. 

The fault in this particular machine is blown IGBTs on one of the DC-DC converters, but there is 16 of them to replace.  

My first step will be to remove the faulty IGBTs, re assemble, provide no battery and test the main board in terms of solar supply  and exiting the DC-AC converter. This procedure is required to ascertain wether the low voltage battery side mess is isolated and hasnt cause any secondary failures on high voltage split supply circuits. Only then can we calculate the cost of damage and the viability of repairing the converter. 

EDIT: oh the two output are not not merely shorted together, theyy first pass thru individual large inductor, current transformer, filter etc. So I assume the DSP can make fine phase angle adjustment to  maintain load balancing. 

 

 

Edited May 6, 2023 by BritishRacingGreen

[BritishRacingGreen]

1 hour ago, BritishRacingGreen said:

3 weeks down the line, and today its time to investigate @ChristoSnake 5kw Infinsolar inverter. I have measured a dead short across the battery terminals. 

I dissasembled the unit in order to expose the DC-DC converter module and the main board (DC-AC plus MPPT).  Below is an image of the two boards, the main board at the top, and DC-DC board at the bottom. 

There are no documentation regarding this 5kw unit. So I had to figure out the whole DC and AC bus topology before I can even start debugging. 

This was very confusing until I at last realized that this is actual a split phase machine, when configured appropriately will deliver ac on phase S and phase R. That explains why we have two identical dc-dc converters as can be seen in the image.  They generate two seperate HV dc busses called BUS- and BUS+. And  they are tied together on the main board to the N (AC neatral). Because the DC bus is really now a split supply bus with negative and positive sources with reference to N, the AC-DC converters on the mainboard can now merely entertain a half-bridge IGBT arrangement to produce AC. But there are two supplies, so there are 2 half-bridges, one for S phase and one for R phase. 

BUT this machine is not configured for split phase, so it is my assumption that the DSP generates the two phases at exactly 0 degree difference (as oppose to 180 for split phase). Then the hardware combines the S and R phases on the AC output board. And yes I have measured a short on this board. 

MPPT follows suit by also generating a split supply. 

So this is actually now two 2.5kW inverters  running in parrallel within the same maxhine. This of course is a gross overkill. This 5kW machine has more heatsinks and power silicon  than a MAX 10kW.  Definately more silcon then Pamela Anderson had back in the day. 

The fault in this particular machine is blown IGBTs on one of the DC-DC converters, but there is 16 of them to replace.  

My first step will be to remove the faulty IGBTs, re assemble, provide no battery and test the main board in terms of solar supply  and exiting the DC-AC converter. This procedure is required to ascertain wether the low voltage battery side mess is isolated and hasnt cause any secondary failures on high voltage split supply circuits. Only then can we calculate the cost of damage and the viability of repairing the converter. 

 

 

Below you can see the damage on one IGBT. This one wanted to explode, the legs were heavily bent, the screw helped from total explosion.this is what I like about an inverter, it fails in style, it announces its pain visually  and leaves a mess as to say : look no further, here is the problem. And if you cannot see it, you will smell it out.

[BritishRacingGreen]

On 2023/05/06 at 6:59 PM, BritishRacingGreen said:

Below you can see the damage on one IGBT. This one wanted to explode, the legs were heavily bent, the screw helped from total explosion.this is what I like about an inverter, it fails in style, it announces its pain visually  and leaves a mess as to say : look no further, here is the problem. And if you cannot see it, you will smell it out.

A couple of young engineers from my previous employer wanted to get into the hardware side of the meanstream residential inverters, so we started a informal workshop thing on Friday in Germiston. Not that they  know less than me, the one engineer has actually designed a 3phase AC drive for railway applications, well above old BRGs paygrade! Reason he developed it is due to peculiar specs : 110vdc bus with 220vac  three phase AC for rail switches (points machines). 

As an excersize he brought along a Schubart Axpert clone thats faulty. This was going to be our reference machine going forward for debugging.  Only to find that the Dry Capacitor Bug has striked again! Half an hour later machine was up running. Which is pity, from the point of view that we want to debug the IGBT drivers to really get hands on. 

So hopefully they will bring a 'better' faulty machine next time, so we can drill down! 

 

 

Edited May 9, 2023 by BritishRacingGreen

[Coulomb]

On 2023/05/09 at 4:28 PM, BritishRacingGreen said:

Half an hour later machine was up running. Which is pity, ...

Yeah. Never a good fault when you need one 

[Carl]

@BritishRacingGreenyou have inspired me to attempt a repair on a faulty Growatt SPF 5000 ES inverter. With MPPT board removed and only battery connected i noticed surface arcing around the Ceramic caps and the DC to DC Bus Side IGBT's located on the bottom of the middle heat sink. There is a fair amount of black dust on the board and some moisture on the fan unit and on the board.  All the IGBT's and Mosfets test ok on the diode test function so hoping that damage is limited or best case no damage. Inverter came up with warning error 62. Please advise what is the best way to clean the board.

[BritishRacingGreen]

3 hours ago, Carl said:

@BritishRacingGreenyou have inspired me to attempt a repair on a faulty Growatt SPF 5000 ES inverter. With MPPT board removed and only battery connected i noticed surface arcing around the Ceramic caps and the DC to DC Bus Side IGBT's located on the bottom of the middle heat sink. There is a fair amount of black dust on the board and some moisture on the fan unit and on the board.  All the IGBT's and Mosfets test ok on the diode test function so hoping that damage is limited or best case no damage. Inverter came up with warning error 62. Please advise what is the best way to clean the board.

Hi Carl, good luck with your journey. Isolpropyl alcohol (rubbing alcohol also called here in SA) is good cleaning liquid and also evaporate easily.  I use a soft brush  but do practice on an old board so you can test your clean. Let the board dry thoroughly, sundry even better. 

The arcing you experiencing sound real bad, and a good clean may go a far mile to solve it. 

I am always confused about Growatt in how much it is a derivative of Axpert. If I may, can you send some images of your mainboard and controller card.? 

Please stay in touch and let us see how you progress. 

What is error code  62 in your user  manual? 

 

 

[Coulomb]

On 2023/01/11 at 10:36 PM, BritishRacingGreen said:

The owner  was woken up by a repetitive clicking sound very early on Christmas day. he discovered that his Axpert's display backlight and LED's   was cycling a number of times per second  , on then off. Also the relays was clicking at the same rate.

It was my turn for this problem recently. It happened when it was raining heavily, and we have shade cloth in the courtyard, so I actually thought for a while that it was regular rain dripping. It was about a 1 cycle per second or two rate, not as fast as some.

Recapping fixed the power supply; thanks again to all who contributed to this, especially @BritishRacingGreen. But it seems that running for a day or so in this stage doesn't do the EEPROM any favours. My first symptom was fault code 73: voltage mismatch. I run 240 V here, as our mains still hasn't caught up to the rest of the world at 230 V. But I soon realised that not only had the  voltage reset to 230 V, the serial number was the dreaded 5535553555355. That means that the EEPROM lost at least part of its contents, or is damaged. Fortunately, I was able to reset the serial number (a good thing, as my monitoring software has to see the correct serial number to know which inverter is left and which is right). I would not have been able to avoid fault code 90, as I don't know the magic bytes to send in the PABC command. But it's an older model that came with main firmware version 72.40, so I'll always have to run patched firmware anyway. I wonder if I've lost all my calibrations... I'll find out soon. Solar charging was also not working, but that might have been because it was too late in the afternoon. The other inverter was still solar charging, but it has panels that catch the afternoon sunlight better.

So: owners of aging inverters, consider a pre-emptive recapping (never convenient, right?), or at least try not to let it run too long in the clicking condition.

Edited May 20, 2023 by Coulomb

[BritishRacingGreen]

3 hours ago, Coulomb said:

It was my turn for this problem recently. It happened when it was raining heavily, and we have shade cloth in the courtyard, so I actually thought for a while that it was regular rain dripping. It was about a 1 cycle per second or two rate, not as fast as some.

Recapping fixed the power supply; thanks again to all who contributed to this, especially @BritishRacingGreen. But it seems that running for a day or so in this stage doesn't do the EEPROM any favours. My first symptom was fault code 73: voltage mismatch. I run 240 V here, as our mains still hasn't caught up to the rest of the world at 230 V. But I soon realised that not only had the  voltage reset to 230 V, the serial number was the dreaded 5535553555355. That means that the EEPROM lost at least part of its contents, or is damaged. Fortunately, I was able to reset the serial number (a good thing, as my monitoring software has to see the correct serial number to know which inverter is left and which is right). I would not have been able to avoid fault code 90, as I don't know the magic bytes to send in the PABC command. But it's an older model that came with main firmware version 72.40, so I'll always have to run patched firmware anyway. I wonder if I've lost all my calibrations... I'll find out soon. Solar charging was also not working, but that might have been because it was too late in the afternoon. The other inverter was still solar charging, but it has panels that catch the afternoon sunlight better.

So: owners of aging inverters, consider a pre-emptive recapping (never convenient, right?), or at least try not to let it run too long in the clicking condition.

My statement on an earlier post in this thread  that its not really needed to preempt an upgrade turned out to be a liitle bit on the wild side. When you come to think of it, the slow unstable sawtooth-like 5V  supply to the DSP can only cause trouble eg. with non-volatile memory devices etc.  

Whats more the 12v rail 1000uF cap actually degrades more ungracefully, but the 12v loads are slightly more forgiving to dips as the DSP. 

So yes, I agree, Axperts older than  5 yrs should be upgraded. 

 

 

 

Edited May 20, 2023 by BritishRacingGreen