Fronius Frequency control not working

Q&A and troubleshooting
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1

Hello,

I have an interesting scenario/s with my workshop solar setup.

I have set up a 48/5000 Multiplus II, along with a Pylontech battery, Cerbo-GX II, Smartsolar MPPT and a Fronius Primo 5.0-1 inverter connected to the AC output and communicating through a direct LAN to the Cerbo-GX II.

Now, everything for all intensive purposes works well and communicates well, except for the Fronius Primo. Although it reliably feeds its data back to the Cerbo-GX and displays everything well, it does not appear to make any attempt to throttle power output under the victron frequency control. The Victron adjuasts the frequency up until the Fronius cuts out on “High frequency cut out”. And to add to the frustration, I bought the Fronius second hand, still under warranty and in very good order. That being said, the original installer, who has now shut up shop, appears to have the admin and owner rights, so I cannot transfer the system from the person I bought it off. His settings page on solarweb.com does not allow for change of owner. I have contacted Fronius help team regarding this and waiting for a reply.

Here are a few point forms to try to lay it out better.

  • All units, including the Fronius, have the latest firmware installed and double checked.

  • Multiplus II is new and shifting frequency smoothly.

  • Fronius is almost new, but second hand and “locked” to a degree. (in progress with tech help).

  • Fronius is not responding to frequency and just puts in full power available from panels until tripping out on high frequency signal from Multiplus.

  • Fronius has FILmin at 47,00Hz. I set the start on Victron Assistant at 50,20Hz as recommended.

  • Fronius has FILmax at 52,00Hz (as opposed to the usual documented 52.80Hz). I set the reduced to minimum at 51,90Hz and the disconnect at 52,20Hz, due to the differences.

  • Fronius does trip once frequency goes above 52,00Hz.

  • Fronius does not appear to respond to any frequency between 49,90Hz and 51,90Hz. The unit just gives full available solar power until tripped.

  • Testing has been carried out under minimal load, medium load and heavy load (allowing the Multiplus to still be in a “charging” state). The results are always the same.

  • I have been through everything that I can access on the Fronius screen and cannot appear to change the situation.

*I have tried cold boots on all systems, with no change.

I hope someone here may be able to shed some light on the current situation.

Thanks in advance.

frequency response 2
frequency response 21536Ă—871 85.9 KB

2

Well…
After two full days of frustration, I can answer my own question.

For those interested, it takes a special code to access the country code and set it up as MG50 (Micro Grid 50Hz).

Now for some reason My FILmin is 46,00Hz and my FILmax is 53,10Hz. So I have adjusted my assistant to leave the start at 50,20Hz as recommended, with the assistant reduced to minimum at 53,00Hz and the disconnect at 53.20Hz, due to the differences.

The fact that I thought the country code must have only been accessible through the Owner’s login was frustrating without any proof either way and nearly all of the official literature never covered it.

Cheers.
John

3

I’m having a similar problem.

CerboGX receives all the data from the fronius, including serial number and latest firmware version. All units upgraded firmware to latest.

Fronius doesn’t wind down at all, battery voltage goes too high, victron trips the grid, (rightfully so).

Fronius documentation is RUBBISH.

I’ve set to MG50, but fronius setting still shows Australia DRM, which shouldn’t be there in MG mode.

Any chance you could share what modbus settings you’re using? FTP or RTU, and Float or Int and??

4

First thing after the MG settings, which should stick to MG or International 50, is to go to info and check the “FILmin” and “FILmax”, as mine differ from all of the documentation.
As an example, my FILmax is now 53,10Hz and not the normal stated 52,80Hz (from memory).
This means that if you leave the standard frequency in the assistant, that the inverter will not produce a high enough frequency to slow down / stop or shut down the fronius. This will cause a battery overvoltage for sure.

You will have to compare your fronius FILmin and FILmax and adjust the settings in the assistant “PV Inverter Support” data.

Cheers

5

Also Craig,
Where are you setting up the MG50 on the fronius?
Is with the taps on the blank button followed by the access code to allow you into the fronius country code setup?

6

Hi John,

The reason why I asked for your modbus settings is that fronius say RTU, whilst Victron says TCP.

FILMax is 53.1
Where is the PV inverter support data on a CerboGX?

I set up the MG50 on the inverter by pushing the back button 5 times, inserting 83887, then scrolling (forever) to MG50. My Primo Model is a 5.0-1 SC, not the usual 5.0-1 AUS.

I’m running a Multiplus 5kW, and a BYD LVL battery, with “Auto Selected” and forced on BMS. In DVCC I reduced the charging current to 50A, which will easily suffice, and reduced the charging Voltage to 53.9V, neither of which had any effect on the Fronius.

I suspect I might have to go into the Multiplus and put a ESS assistant in to increase the frequency?? It would be nice if in one of the menus the Cerbo GX shows the frequency, so that one could troubleshoot.

Thanks for your help too.

7

So, update…

This is day four of frustration for me. :frowning:

I set the country code to EU - middle voltage, (FILMax 51.5V) and finally the Fronius started ramping down, but so slowly that the BYD battery voltage went too high again and the victron (rightly) tripped the grid.

Seems like the modbus doesn’t control at all.

Will change the priorities in the fronius to use frequency above modbus and see if we can improve things.

8

So I tried that, didn’t help.

However the Fronius went from displaying “Running MPPT” to “Running”

Fortunately I have two excellent SmartSolar MPPTs that keep me charged in the meantime.

9

Craig,
I am using a direct LAN network system from the fronius inverter to the CerboGX. The little dipper switch near the RJ45 socket needs to be in the appropriate position. I assume that you have this correct on yours, as you commented that your CerboGX is picking up the details of the fronius.
I am using VE-Direct from my MPPT to CerboGX.
I am using VE-Can for my Multiplus II to CerboGX.
And I am using VE-Can-BMS to my pylontech batteries.

The PV inverter support data is in the “assistants” tab on “VE-Configure” for the Victron inverter.
The settings sound somewhat the same as mine as my FILmax is also 53,10Hz.
See my image for programming.

Assistant1
Assistant1632Ă—494 92.6 KB

10

I believe the code is “73887”, but that may have been a typo on your behalf.

The code I used was simply “MG50”.
This set up the “FILmax 53.1Hz” and I programmed the victron multiplus II “assistants” accordingly.

11

Remember. The modbus does not control the fronius. Only the frequency does.
The modbus (any bus) transfers data relating to the fronius output for the CerboGX to understand.

12

“I am using VE-Direct from my MPPT to CerboGX.
I am using VE-Can for my Multiplus II to CerboGX.
And I am using VE-Can-BMS to my BYD batteries.”

I changed pylontech to BYD, but I’m running the same.

Typo on the code, should be 73887

I’m using wifi instead of a LAN cable, but no dropped packets or errors according to the fronius or victron.

I have not yet used the victron VE_configure on the Multiplus, the documentation says you shouldn’t have to. Currently I dont have a computer on me with a RJ45 port.

Fronius have a button that says “control over Modbus”, and I ticked it. And why wouldn’t it, if you can tick the box and prioritise the control in the DNO editor?? That’s two confirmations, is it not??

I have raised a support issue with both Victron and Fronius.

The other issue is that in the Victron documentation, they show a screenshot of a setting that is completely missing from my Fronius…

I am missing the DPL_SOFTLIMIT settings, no matter what setting I put the country code to, or if i put it to MG50.

Also, interestingly, when I set it to MG50, there’s still a setting there for demand response, specific to Australia. Why would you want demand response in an off grid scenario??

I suspect that some engineer at Fronius has ticked the wrong box or boxes on my inverter setup.

I ran out of sunshine for the day, so I poured a beer.

1 Like
13

You really need to have access to your Multiplus through VE_Configure.
The standard values are not always the best. Frequency included.
AS I said. The inverter frequency output is what controls the fronius inverter output.

I think that you need to get and use VE-Configure.
If you have internet access to you cerboGX, then you can download and upload the adjusted files through “Victron Connect” (downloadable). You do not need the MkIII USB adaptor in most cases. But, the Multiplus needs to know the frequency range that it is working in and be able to respond to that.

14

Just found this in a seemingly unrelated document:

"Inverter is connected to the Fronius Smart Meter via HARDWIRED modbus RTU RS485. THE FRONIUS EXPORT LIMITATION DOES NOTE RELY ON ANY WIRELESS COMMUNICATIONS LINKS"

I think we’ve found my problem.

I have wired it up, configured the LAN settings and await the sun tomorrow.

Wonder if the new DNO setting appears when the coms are hardwired???

Once again, thank you for your help

1 Like
15

Okay…
I am admittedly not clued up with the fronius smart meter side of things.
Best of luck with it though.

But it is surprising just how much documentation is left out of official documentation and normal google searches. The strangest things just seem to pop up out of nowhere after what seems like eons of searching.

Cheers.

16

I’ll let you know how I go.

In the meantime chuck this code into your inverter:

77634

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17

Hopefully get a chance to try it tomorrow.

Cheers

18

So guess who’s got a dead ethernet port on their Cerbo GX?

I tried everything today. Shows “retrieving IP address” without a cable being plugged in.

I removed all the other power draw, changed cables, changed router, downgraded firmware, upgraded firmware, turned off “large”, turned off wifi and bluetooth, changed to the old interface, removed the VE-Direct cables, restarted, rebooted, power cycled, factory reset and held my tongue in a different spot.

So going to have to make a warranty claim, but I’ll have to buy a second one anyway, because without the Cerbo, there’s no BMS, which means no power.

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19

My cerboGX from memory displayed “retrieving IP address” (from memory) when the “A-B” switch in the fronius was in the wrong position.
Check the switch position, check the cat6 cable integrity and check the seating of the plugs. I also check whether the actual RJ45 data light at teh recepticles are flashing (transmit data).

I would have to compare (it is now dark) how my system performs with the LAN plug unplugged.

From memory, it still controls the fronius via frequency through the output AC, but just does not receive the data to calculate true power usage.

Cheers.

20

I spent all weekend last week troubleshooting my AC coupled inverter with Pylontech Batteries.
In the end even though the BMS of the batteries forces on the DVCC and controls the charge currrent level it has no real effect on the frequency shifting.
What i did was set the charger tab up in the multiplus via Ve configure to the pylontech values to match the BMS and then the frequency shift works perfectly.
I found an old post from Guy that mentioned the frequency shift uses the voltage at the multiplus terminal not the BMS.
Hope that helps someone out there.

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