It seems I'm just not having any luck with there Axpert Inverters . 

I have 2 x 5kVa interters in parallel. Running 71.50 firmware on both.
Details of the install are here: https://powerforum.co.za/topic/3359-midlands-off-grid-installation/ 

 

I've had an ongoing problem with the inverters consistantly over-charging (i.e. <54v) the Pylontech batteries. Fortunately the batteries BMS system kicks in at 54v and stops further charging.

Alarm light comes on, on the batteries and the voltage drops off. The inverters do not keep hitting them with the higher voltage once the 54v max is reached once in a cycle.

 

I initially set the inverters to the values specified by Pylontech but had the overcharging issue, then reduced both the bulk and the float charge values (I recall @Coulomb suggested lower values in another post I made reference to the overcharging issue) and before I got to check these out properly I had an incident where my electrician damaged the AC input and AC output connectors by over-tightening them (took 5 weeks to get repaired!). Having reinstalled the inverters I'm still having the batteries hitting their 54v limit. I played with all the relevant settings, I've checked the connection cables, double checked them, but the issue persists.

 

I have since run the inverters in parallel but with PV power supplied independently to one inverter at a time and it would seem one of the two inverters (the one acting as the slave) does not stop the charging process (although it does reduce power going to the batteries). Essentially it hits the bulk charge voltage, then drops to the float charge and holds the float charge for about 50 minutes but then steadily starts the charging process again until the batteries BMS kicks in. I've attached a screen shot of the ICC data output for yesterday (power to Master inverter only) and today (power to Slave only)

 

Anybody had this issue previously and have any idea on how to rectify it?

I have the same problem on a 5Kw parralei system with Pylons and dont how to Rectify

@Dikkes I've been in contact with Mustek direct (after eventually getting through to someone that would actually help). After detailing my issue as per my 1st post in the thread I was asked the following (my responses in red😞

Had a chat with our technician regarding your issue with the inverters, there is  a few things the tech need from you:

1: Can you connect the (slave)inverter to you pc and give us the data log (via watch power)  to determine at what voltage the unit is charging.

I've been unable to get watch power to recognise the inverters. The software loads and the inverters give 'live' info but I cannot get the events or data logs to download as the units are recognised. Can you advise on how to get this done?

2: Advice if there is any error code coming from the inverters.

There are no regular error codes that come up, however I have got error code 80 (communication error according to the manual) previously when changing the inverters charging source priority from "utility" to "solar first" or "Solar Only"

3: Check the setting value of setting no 2 and setting no 11 of both inverters and send it to us.

Both settings are currently set to 30A. (PLEASE NOTE - that this is a completely off-grid installation, so the AC charge current is not relevant).

I have changed this value and put it as low as 10A and still have the issue. According to the Pylontech manual this can be set as high as 125A, (N*25A, where N is the number of batteries)

4: Change the master inverter to slave and slave to master and check if it doing the same.

I did this this weekend and the units performed fine on Friday, but then over-charged the batteries on Saturday, Sunday, Monday & Tuesday.

I have reverted back to the original Master/Slave configuration and only PV power going to the Master and the system has performed as expected with no overcharging recorded today.

5: Connect the unit individual and test

I still need to undertake this test. I'll get it done ASAP and get back to you

**Can anyone please explain to me how to set the inverters back to solo operation again, so that I can undertake item 5? I have removed all the external parallel cabling and tried to change setting 28 (if I recall correctly), but I have no option other than PAL. 

 

So I still don't have a solution to the issue but it does look to me as if one of the inverters is faulty. I'm just waiting on Mustek (breath firmly held) for a response on how to proceed.

 

Edited July 31, 20196 yr by Super_mil

22 hours ago, Super_mil said:

**Can anyone please explain to me how to set the inverters back to solo operation again, ... but I have no option other than PAL.

This is an FAQ. You have to do this with the rocker switch off. Do this during the day with solar connected so that there is a charge source, so the inverter doesn't switch off while you are saving the change. Or just be quick and use escape to save the setting.

Thanks for the info @Coulomb, I appreciate it.

 

I managed to run each of the inverters this weekend as standalone units one at a time. The units performed fine and did not exceed the bulk and then float charge thresholds during the day and responded immediately if I changed the value of the float charge. I started each time with the batteries close to full charge and then just kept an eye on things for the over an hour each time and the float charge was maintained. 

I also initially ran the system in the normal parallel setup and once again the units went beyond the 54V max of the batteries (and well beyond the bulk and float charge thresholds set on each inverter).

What I have noticed is that when each of the units is run as a standalone they report what I believe is the correct PV power coming in from the panels (6 x 355W panels = MAX 2130W). Yesterday the panels had a max of 1380W which is believable. Whereas when the units are connected in parallel, my MAX PV power is 4260W (12 x 355W), and from the data, it looks like I'm getting figures well into the 6000W range so there is some sort of error there. I'm not sure if this could be the cause of the issue? I'm also not sure how to rectify this? I have asked the Mustek guys to comment but thought I'd post here just in case someone has experienced the issue before and knows how to fix it.

 

Data logs from yesterday posted for completeness.

Slave - Event Log-20190804 12h53-00872.xls

Master - Event Log-20190804-12h52-00864.xls

Slave Data log 20190804-12h51-00872.xls

Master data log_20190804-12h50-00864.xls

00864-SOLO-20190804-144h4.xls

20872-SOLO-190804-16h22.xls

Hi,

Have you found a solution yet?

I'm running 2 x Axpert inverters and 3 Pylontech batteries + 10 solar panels. Settings are at 53.2V for float and bulk charge via Raspberry Pi.

Having the same issue...Batteries reach 100% and soon after, batteries shut down. I've watched the charge hit just passed 54V and then power trips as batteries go to alarm.

 

Anyone know the solution?

9 hours ago, Eddie R said:

Anyone know the solution?

I don't. It sounds like either a paralleling board / paralleling cable / current sharing cable issue, or a firmware issue. It seems unlikely (but possible) that you both have cabling issues, so that leaves a firmware problem as the likely (IMHO) problem. Unfortunately, I don't have firmware for these 450 V MPPT models to read, and the likelihood of spotting an error like this in machine code seems low.

Hi @Eddie R unfortunately I have yet to find a solution. I've been in contact with both Mustek JHB and DBN and I've yet to get a solution. I was about to take the units in for testing based on responses from both Mustek offices, but I fortunately managed to contact one of the tech guys (Charlie Naidoo) in the DBN office and discussed the issue I'm experiencing. I also needed to discuss with him testing times and if it was possible to send each unit in individually as I'm off grid, so no inverters means no power. It was recommended that I do not bring the units in as since they were operational as standalone units, it would be unlikely that they would pick up the issue on their side. They then said they would contact their Taiwanese supplier (Voltronic) to discuss the issue and get back to me but as of last week they had not had a response from Voltronic.

I agree with @Coulomb that the issue is either firmware, parallel board or cables that are the issue. 

 @DaveSA I can confirm 100% that the load sharing cables were connected. I checked and double checked the cables for any sign of damage, made sure the ends that terminate in the small green plug were good and made sure of there orientation in each inverter. Unfortunately the issue persists.

At the moment I'm still only running a single inverter and half the number of panels as I do not want to jeopardize the batteries and this has been running fine for the past couple of weeks but is obviously not what I had wanted.

I tried changing the BULK and FLOAT charge voltage to 57.2 V. Today it seems to be working...

Let's see if this works long term on both inverters...

On 2019/09/03 at 3:43 PM, Eddie R said:

I tried changing the BULK and FLOAT charge voltage to 57.2 V. Today it seems to be working...

Let's see if this works long term on both inverters...

57.2 V?? How can that be a solution since the Pylontech BMS trips at 54 V?

I think he meant 52.7V.

52.9V still works for me.

 

22 hours ago, RikH said:

57.2 V?? How can that be a solution since the Pylontech BMS trips at 54 V?

Sorry...must have been 52.7 V....

Just now, Eddie R said:

Sorry...must have been 52.7 V....

Seems, there is less drama at 51.9V for bulk and 51.8V on float...

13 hours ago, Eddie R said:

Sorry...must have been 52.7 V....

Haha now I understand... 😅

OK, I've been working with Centurion Solar with my Raspberry Pi. Have to say, great service from them!

Yesterday they made some changes to the programming of the Pi (sorry beyond my limited understanding) and we reset all voltages to the Pylontech recommendations - 53.2V on both float and bulk charge then restarted the Pi.

For the 2nd day in a row now, the batteries have reached full capacity and are well controlled by the inverters below the 53.2V setpoint!

Really hoping this is the solution to my battery tripping issues!!!!

Actual Solution - talk to the experts!

11 hours ago, Eddie R said:

OK, I've been working with Centurion Solar with my Raspberry Pi. Have to say, great service from them!

Yesterday they made some changes to the programming of the Pi (sorry beyond my limited understanding) and we reset all voltages to the Pylontech recommendations - 53.2V on both float and bulk charge then restarted the Pi.

For the 2nd day in a row now, the batteries have reached full capacity and are well controlled by the inverters below the 53.2V setpoint!

Really hoping this is the solution to my battery tripping issues!!!!

Actual Solution - talk to the experts!

Hi, did your problem persist or was it resolved, if resolved, what is your settings now?

still running in parallel or stand alone?

i will try and post my graphs tomorrow, seems that I have a real major problem that just won’t go away.

 

Just an update to this. I have finally fixed the issue, by getting both inverters replaced with new units and updated firmware (71.70).

It would seem (as expected) that the older 71.50 firmware was the issue. The issue did not resolve itself by running the master with the updated firmware and the slave with the old firmware, I tried. Both units need to be running 71.70.

It should be noted Mustek were of no help through this process 👎

Jaco de Jongh just helped me with updating the firmware on my two Mecer inverters. The voltage control on the battery charge seems correct now...

Thank you Jaco for your time! Will definitely use you in the future!

Anyone looking for excellent assistance on your solar, Jaco is your man!

22 hours ago, DaveSA said:

Hi, to which firmware version did you update?

Apparently the "latest version" I'll need to check...

On 2020/01/12 at 6:23 PM, DaveSA said:

Hi, to which firmware version did you update?

Firmware 71.71

Hello...

where to get the firmware update ? I'm running 71.30 on my Voltacon Axpert King 5KVA.

Thanks