Axpert MKS 5Kva inverter firmware upgrade

Deckert

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Joined
Jan 13, 2004
Messages
351
#1
Hi y'all,

We recently had a prolonged power outage (due to heavy weather, lightning at the sub-station). My Axpert inverter and 4x170Ah batteries were able to run the house base-load for about 12 hours, but the outage was 26 hours.

I wheeled out my 10kVA generator (an Italian-made Linz alternator and a Honda engine) and connected it into the pre-installed socket, but alas, the Axpert was refusing to accept the generator power as input, regardless of the APL/UPS setting. A friend of mine said that he had upgraded his Axpert firmware from U1-52-30 to U1-72-40 to fix this problem, so I set out to do the same and document the process here.

I'll post some oscilloscope waveforms in the next post.

So first, just checking my current firmware version:

lcd_before_upgrade.JPG

Next, plug in the serial cable that came with the Axpert and plugged it into my FTDI-based USB-to-Serial convertor. It's important to note that you have to map the USB-to-Serial convertor to COM1, else the firmware upgrade app will not detect the Axpert. Most USB-to-Serial drivers support this under the Advanced tab:

com_port.JPG

The upgrade application is simple to use. Run the .exe file and it will do the rest. My upgrade took about 9 minutes to complete (the Axpert communicates at 4800bps). Once the upgrade application is done, it will pop up a window saying so. Exit the application and start up the Axpert WatchPower application. Make sure you restore all settings to default, apply them, then restart the Axpert Inverter by switching it off, then on again.

firmware_upgrade_app.JPG

After boot-up, your Axpert should now display the new firmware version:

lcd_after_upgrade.JPG

--deckert
 
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Deckert

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Joined
Jan 13, 2004
Messages
351
#2
Waveform comparisons of municipal feed, generator and Axpert

Hi again,

So here are a few waveforms I took with my trusty HP DSO. I used a 1:100 probe and my Oscilloscope runs on an isolation transformer (else you'll blow your 'scope to bits).

The first one shows the Eskom feed. It's fairly clean, except for a fast drop-off just after reaching peak:

waveform_eskom.JPG

Next, the generator waveform without any load on the generator. Note the little glitch on the rising edge. As you'll see later, that glitch is not so little:

waveform_generator_no_load.JPG

Next is the generator with a 2kW resistive load (kettle). Note the glitch is gone under load. Also note the frequency is mostly at around 50Hz, but the generator does jump around slightly with a min frequency of 49.2Hz and max of 50.8Hz measured. I suspect this might be what was causing the Axpert to reject the power feed from the generator.

waveform_generator_2kw_load.JPG

Here is that same (no-load) waveform fed to my deep-memory DSO. You can see the glitch is actually a 48V dip with a recovery time of about 200 μs:

generator-no-load-zoom.jpg

Finally, after the firmware upgrade, my Axpert is happy to charge the batteries and also pass load onto the rest of my house:

charging_on_generator.JPG

Finally, just for interest sake, here is the output of the Axpert while running from battery and servicing my house (in other words, whole under resistive and inductive loads). It's a fabulously clean sine wive - I'm really impressed with it:

waveform_inverter_output.JPG

--deckert
 

bees

Well-Known Member
Joined
Oct 23, 2004
Messages
483
#7
Hi Deckert, thanks for this. This is the first thread that came up on Google when searching for Axpert firmware upgrade.

Can you check what else changed in the firmware? When I installed my inverter end of 2014, the option of pulling power from sun, then Eskom, then batteries weren't there.

Do you know if this is now possible with the latest firmware? Must be honest, I haven't read the forums you linked to, will go read later.
 
Last edited:
Joined
Apr 9, 2015
Messages
5
#8
Hi Deckert, thanks for the detailed information - very informative. I can not get my Axperts to take generator power. It tries, but after 10 seconds or running in bypass mode it drops the AC in from the generator. Have tried two generators with AVR but no joy. It is one of the latest inverters and running firmware version 72 70 on U1. Do you have any advice for me?

I am hoping to get a friend here tomorrow to scope the AC to see how bad it is but I know that these generators work on other inverters I have worked with (Microcare and Victron).

Much appreciated.
Hannes
 

Deckert

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Joined
Jan 13, 2004
Messages
351
#9
Hi,

Phew - been a while since I've posted to this thread (I sort of neglected it, sorry). Had a few PMs about it, so I thought I'd just update where I stand on things:

1. I doubt the Axpert inverters can work with Lithium-based batteries, the charging curve is very different
2. I got the firmware from our supplier who got it from Voltronic (the manufacturer)
3. I have no idea what else changed in the firmware - only that it is supposed to work with slightly less stable AC feeds
4. Here is a download link https://www.dropbox.com/s/g1gxg9zj275rp8p/Reflash-72-40-U1.zip?dl=0

The firmware version is 72-40-U1. Only upgrade from version 52-30-U1 and don't ever downgrade to the version I supplied. The ZIP file contains a .doc file with some additional instructions on what to do after the upgrade. Also lets you set many extended features on the Axpert via a fairly friendly GUI.

As always, you use this firmware at your own risk - if you brick your inverter, don't complain ;-)

--deckert
 

Naks

Expert Member
Joined
Jun 3, 2009
Messages
3,705
#11
chaps, while we were away this weekend, the power tripped, and never came back on.

When I got home, the battery earth leakage had tripped, so I reset it, and then the Axpert showed error code '09', and refuses to start.

Do you guys know if this is repairable?

thanks
 

Gnome

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Sep 19, 2005
Messages
5,743
#12
According to this, the errors means "Bus soft start failed". Whatever that means.

They likely mean the DC boost converter but the fault could be on the inverter stage also.

Out of curiosity, did you use the solar functionality of your Axpert?
Also which model do you have?
 

Naks

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3,705
#13
According to this, the errors means "Bus soft start failed". Whatever that means.

They likely mean the DC boost converter but the fault could be on the inverter stage also.

Out of curiosity, did you use the solar functionality of your Axpert?
Also which model do you have?


Yeah, saw that as well. Battling to find a repairer in CT.

this is the 5kV model, but I don't have solar. This was a battery backup for my electronics and garage door.
 

Gnome

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#14
Yeah, saw that as well. Battling to find a repairer in CT.
Have you tried calling places like Proline or Mecer, they sold these things so maybe they can point you in a direction.

If I'm perfectly honest I think our country is more of a replace than repair type deal. iFix it or such places maybe? Give them a call ask if they have an idea. Try call AC/DC, Communica or Mantech in Cpt and ask if they have some thoughts?

Lastly if you never find someone and you've decided to write it off, PM me. I can try fix it (I do a lot of electronics and I've repaired some UPS' before). But I could screw it up more, so you walk into it with, maybe I'll get it fixed, maybe it'll be more screwed.

this is the 5kV model, but I don't have solar. This was a battery backup for my electronics and garage door.
Ah ok cool. The reason I asked is, without solar these things are pretty bullet proof (solar is the cheap/weak component). It shouldn't fail like that. Do you think it is possible there was a lightning strike or similar serious power problem?

The RCD/EL that trip to me is suspect.
 

Naks

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#15
Doubtful it was a lightning strike, the inverter failed on two Sundays ago at around 9am, it was a clear, sunny day.

Thanks for the info, will call around tomorrow.
 

Shellyb1

Expert Member
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Jun 23, 2011
Messages
1,399
#16
Doubtful it was a lightning strike, the inverter failed on two Sundays ago at around 9am, it was a clear, sunny day.

Thanks for the info, will call around tomorrow.
Try these guys out for your inverter repair. They did mine a few weeks ago. Had to ship it to Cape Town but their pricing for it was not bad at all and I am back up and running

https://www.rubiconsa.com/

My inverter is a cbsolar - a rebranded Axpert by the looks of it.
 

Gnome

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Sep 19, 2005
Messages
5,743
#18
Chaps, the inverter is kaput, no way to repair.
Feel like donating it for parts?

Since you aren't using the solar get that model. It is based on the newer VMII and the solar charger is PWM which is why it is cheaper.

Unless you actually have solar wired into the device the MPPT/PWM controller doesn't even power on. So if not using it, it is literally money down the drain.
 

Naks

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#19
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Gnome

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#20
Nope, no solar, and that's also what the chap from FCS recommended.
If I had to buy a new one now I would buy that model. It has a few internal improvements (and better specs), it doesn't have the overpriced MPPT and the footprint is smaller also. Overall win-win.

Just waiting for stock to arrive and will order through TakeALot.
Not that it matters too much but Takealot is just ordering via FCS (3rd party seller according to their site). FCS seem legit

Once I get the unit back, I'll PM you.
Thanks, if you need help I can also assist, SB is not too far from me. Curious myself to see what went wrong with it. Did they say?
 
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