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High charge current alarm

Hello, hoping someone can advise me with a High charge current alarm.

I have an off grid system

Fronius inverters

Victrion multi plus

and Pylontech battery's (30kwh useable)

The problem I am having is when the Batteries are full and my inverters are restricting the power off the roof until a large load is being used (e.g kettle) then the inverters step up to provide for the load.

Once the load is switched off the power is diverted to the already charged batteries causing "High charge current alarm"

any help would be appreciated (-:

alexanderr asked

0 Answers

Differing Loop Impedance on Quattros for 3-phase system causing Fronius malfunction?

Problem: Fronius Symo 15.0-3-M stopped functioning.

Status: Fronius Reporting ERROR 453

Grid Voltage and Power Module Discrepancy


3x Quattro 10KVA

1x Symo 15KVA AC-Coupled on Quattros AC-out

We have tested loop impedance:

L1 Quattro 5.0Ohms

L2 Quattro 4.8Ohms

L3 Quattro 0.75Ohms.

We are concerned that the difference in loop impedance may be causing the malfunction of the Fronius SYMO. We are also concerned that while replacing the SYMO may provide a temporary resolution, the difference in loop impedance may cause an eventual failure in the new SYMO.

It is to be noted that the L3 Quattro was replaced within the last year.

L1 and L2 Quattros were purchased and installed around 2015.

Your expert knowledge, comments, or advice is appreciated,

sparkpoint-solar asked

0 Answers

Charge batteries from the Fronius inverter and Victron gives an increase in frequency and cuts off

Good afternoon! It is possible to charge batteries from the sun from the Fronius inverter, and Victron gives an increase in frequency and cuts off this possibility.

How to fix it?

more than 90% of the victron charging does not work.



Admin AvanteComUa asked
Admin AvanteComUa edited ·

0 Answers

Fronius firmware Update


Has anyone tried the latest firmware for the Primo,s in an AC coupled off-grid system?

The latest version is (fro33350.upd).

Interesting to see how its going to perform in regards to the (Flickering) issue that sometimes seems to be an issue. I also noticed in the change-log that they mentioned that there is some changes in the MG50/60 off-grid system setup. Does any one know what they are?


Dave Rae asked
scraggs commented ·

0 Answers

Cerbo mixing up measurements , Fronius continuously throttling

Hello everyone,

we have a special case, where I could not find any answer in the community, hence decided to write here , maybe somebody has a solution.

Following is the setup :

1. 12 x Quattro 48/15000

2. 6 x Fronius Eco 27.0

3. 4 x Smartsolar 450/100

4. 500kWh Pylontech batteries (US3000 )

5. Cerbo GX + Touchscreen

Fronius inverters are connected to AC-Out 1

Grid is connected to AC-In 1

Communication of Cerbo and Fronius are over LAN

All firmware is updated,

ESS asisstants are loaded to all the inverters. Grid can only give 100A per phase, hence on quattro's also the input current is limited to 20A each, to avoid overload on the grid.

System works fine during off-grid (when grid is shut down)

as soon as grid is connected and the power generated by Fronius exceeds the power requested by the loads, cerbo starts mixing up data. For example it suddenly shows no loads at the output for a few seconds and this causes him to send the command to Fronius inverters to step down with the production , although in reality the loads are more or less constant and battery not yet full.

This problem repeats itself as long as the PV generation is higher than the loads. Fronius inverters try to ramp up but then they are throttled due to false measurements. This is quite unhealthy and very inefficient.

Currently I have disabled ESS , instead I have uploaded the PV Inverter Support and the general flags for AC ignore assistants , however this is not a good solution , as the customer would like to set the SOC levels himself.

What could be the reasons ? Where does cerbo get the measurement data from ? Could the cerbo be defected or somehow slow in reaction / calculation ? or problem somewhere else ?

Would appreciate your comments very much.

Best Regards

bulraydin asked

0 Answers

Fronius Modbus "float" setting also working?


i just started my Victron installation for test purposes, and have not set up my Fronius Modbus connection correctly.

It is still on Modbus TCP "float" instead of the Victron-required "int+SF"

I wanted to change this later.


i can see my Fronius Inverters and all its data on all Victron Display, VRM, etc.

Seems to work fine.

So... is "int+SF" really required at all? Or does it work with "float" also anyhow?

If so it would be nice, because then i would not need to change all my other external modbus datalogging, etc. that already exists

Or are they some specific registers, that only work on "int+SF" correctly?

pedaaa asked
pedaaa edited ·

0 Answers

Fronius disconnect loop (Quattro in ESS and Pylontech batteries)


I have a Fronius Primo 8.2-1 connected to two Quattros 48/5000/70-2x100 running in parallel. In addition, we have two SmartSolar MPPT 250-100 chargers and a mix of Pylontech US2000, US3000 and US3000C (12 batteries in total - with the US3000C as masters and the rest as slaves, with three 120A rated cables going from the Lynx to the batteries, distributed as equally as possible).
The Fronius is connected to AC OUT 1, setup is MG50 and in ESS the frequencies are as recommended by Victron: Start 50.2 Hz, Minimum 52.7Hz, Disconnect 53.0.

In Venus, under Pylontech battery, the parameters are identified as follows: Charge Voltage Limit 53.2, Charge and Discharge Current Limit 335.0 A.


When there is enough sun, I get 10kW from the two SmartSolar chargers and around 6kW from the Fronius. Problem can be spotted in this graph, usually at ~11kW sent to the Pylontech batteries (anything above 220A for more than 10 seconds), the Victron raises the frequency and the Fronius gets disconnected with error 105 (too high frequency). The Victron then drops the frequency back to 50Hz, Fronius spends some time and does its checks and after a while its connected again, rinse and repeat.

When there is high load on the house, the Victron leaves the Fronius to work at its full potential, sustaining 5.5-6kW for as long as there is enough sun. So my guess is that the reason for this behavior is somewhere between Victron and Pylontech.

Does someone have an idea why this is happening, what can we test and do to solve this?

Thanks in advance.

Kitaigorod Alexandru asked

0 Answers

Generators compatible with Fronius grid tied inverters.

We have a Fronius grid tied inverter connected to the output of a Quattro. Fronius grid tied inverters have a shutdown facility which utilises frequency shifting the ac by 1 Hz.

Suppose we have an ESS with a Fronius, Quattro and a generator. If the generator kicks in and the frequency is not exactly 50 Hz, the Quattro will frequency-track it and in doing so inadvertently shut off the Fronius grid-tied inverter.

Do we have to purchase a super-stable generator with exact 50 Hz frequency in order to prevent conflicts between the frequency of the generator and the grid-tied inverter?

Barry Clark asked

0 Answers

VE.bus voltage high and not stable causing output voltage to be unstable and trip

We have a 5kva MP setup with a 5kw fronius grid tie inverter.

We see the ve bus voltage to be very erratic during sunny hours of the day when the battery is full.

The battery voltage is stable but the VE.BUS voltage go as high as 64Vdc, causing a output voltage imbalance and the inverter trips out.

It is a 5kwh BSL battery with comms to the gx device.

What can cause this issue?dc bus.png,



martin-van-biljon asked
martin-van-biljon commented ·

0 Answers

Two fronius inverter connected to AC-OUT: 1.0 rule

Hi together,

I have two fronius Symo 15kVA with 36.5 kWp combined PV panels, currently connected at AC-IN, so they will be shutdown during grid outage.

In addition I have 3 Multiplus-II 3000 with 8 Pylontech US2000 48V and 4kWp via an MPPT-RS.

Everything is 3phase in my household (heat pump, oven, cooking, wallbox...).

If there is a long power outage (days to weeks) I'd like to have the possibility to rewire the fronius inverters to AC-OUT and reconfigure them to MG50 frequency shifting to also use the power that they generate.

Now my question: is it possible to use this configuration if I limit each fronius to max 4.5kW via Fronius Grid configuration? This should then be 2 x 4.5kW = 9kW distributed over 3 legs. So it should still match the factor 1.0 rule because there is never more then 3kW on AC-OUT on each of the Multiplus-II 3000.

Will frequency shifting still work in this configuration?

christoph-dunker asked

0 Answers

VRM. Duplicate Fronius in device list and missing data


I have developed a strange situation in the last weeks with VRM portal. The system was installed in January and until now there was no such issue.

The system is grid connected 3 phase Multiplus II with AC coupled Fronius Symo 12,5. I have Cerbo GX with USB stick connected to it. I connected the stick after these issues started. First I thought that the memory will get full on CerboGX when there is no connection. This has not solved the issue.

My VRM portal ID is 102c6b9d0131 (maybe Victron VRM team can check)



I have duplicate Fronius device in the device list.


I have tried to delete both of them separately and together, they both appear back.

I am missing dashboard historical data. Advanced data is all correct and there is plenty of sun. Production is usually 90 - 100 kWh with this kind of day. Dashboard shows only 13 kWh though. Other values seem suspicious as well.



I think it is just a visual issue. The data actually seems to be there.

Karl Laasik asked
Karl Laasik edited ·

0 Answers

Flimsy regulation of frequency shift & Charge current limitation in ESS offgrid mode

I have a system running with a Multiplus II 3000/48 and 8kWh LiFePo battery, and a Fronius Primo 3.0-1 PV inverter. The Microgrid setup on the Fronius is active and the system is working properly overall, also the power reduction via frequency shift works in general.
However, I find the regulation of the frequency shift to be not optimal. While the rate of frequency change was mentioned many times, another problem is the amount of frequency shift.

Since the Multi can provide 35A max. to the battery, that is about 2000W AC in, it's never neccesary to lower the power of the Primo below that 2000W, hence the frequency should never have to rise above ~51.6Hz (unless the battery voltage reaches it's maximum).
However if the AC load or sunlight is fluctuating only a tiny bit, the charging current will rise above 35 Amps and the Multi will "panic" and rise the frequency to 52.7 instantly, killing the Primo and it will take a long time to return to normal, which is in most cases at ~51.1 to 51.3Hz with a bit of AC idle loads.

Why is the regulation this way? The Multi knows the maximum PV inverter Power is 3000W, so technically it should know that rising to ~51.6 Hz would be enough, even in the worst case.

Since there doesn't seem to be a way to solve the problem directly, I've tried to lower the charging current, so the regulation has a bit more room for error. However, I found that neiter lowering "Charging current" setting to 33 Amps in the calibration, nor setting a "Charging power limit" in the control settings is affecting this regulation in ESS - No grid mode, it always tries to maintain 35 Amps.

Why are these settings only working while connected to a grid?

Thanks for your help!

kaffeetasse asked
Alexandra commented ·

0 Answers

How to prioritise Zero feed-in limits across multiple Fronius PV invertors?

I have a very specific setup of ESS configuration with 2 Fronius Inverters (while one is regular and one is hybrid with 12kWh Fronius battery connected).

ESS is setup with Zero Feed in.

All works perfectly except one small deficiency. When there is zero feed-in limit activated.. the power decrease is applied to both Fronius invertors equily which is making system a bit less eficient.

It would be more efficient if I could priorities limitation across Invertors so hybrid one gets limited first and regular one gets limited as last. This way the hybrid one will shift it's surplus PV energy to it's local battery while the regular one still goes full speed.

I guess it's more like a feature request rather than a question on how to setup.

Thank you for your thoughts.



jaro2k asked
jaro2k edited ·

0 Answers

Fronius, Multi, ESS, 3-phase switch

Hi there,

I want to build the system below:

  • 15.0-3-M Fronius with 20kWp panels, 1 array east of 8kWp and 1 west with 12kWp
  • 3 * Multiplus-II 48/5000
  • Cerbo GX
  • 4 * Pylontech US3000C
  • SmartSolar Charger with 2-4 panels (just as backup to be able to start the system if the battery is empty)
  • 3-phase switch


My supplier demands, that the PV system feeds directly to the grid through an own grid meter. 100% of the production has to be measured (and sold first). But I have the possibility to use the production immediately myself and it will be discounted from my electricity bill. So if I charge the batteries (from the grid) when there is a lot of production from the PV system, it'll cost nothing.

To me, this can be solved with this setup and ESS (correct me if I'm mistaken, hopefully not... ;-) ). But there are a few questions:

  • Is another energy meter needed to measure the production of the Fronius, or will the Cerbo GX communicate with Fronius directly?
  • As this setup does not allow the system to produce electricity in case of a longer black out, I wanted to add a 3-phase switch to get the Fronius "behind" the Multis. This might not be legal, but who cares in case of a longer black out?
    • So, is this safe (if done properly), or will it lead to problems with the Multis?
    • How about ESS? Will it have to be reconfigured to meet this new position of the Fronius?
    • How will the Multis then limit the Fronius production? Only via frequency shifting? Are there other options?

I've studied the documentation for two weeks now, but it is simply too much information to get to the bottom of it. Hopefully this community can give me advise and reassurance. Thanks in advance for your help!

Kind regards,

hanswurst asked
hanswurst commented ·

0 Answers

Fronius chart missing on VRM dashboard

Hello everyone,

I can't see the chart of my Fronius PV on the VRM dashboard.
There's some kind of configuration to show/enable it?


Many thanks!
Best regards from Portugal!

bvg asked

0 Answers

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