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Multiplus Quattro AC frequency Hz variations

I've been trying to get to the bottom of why we have some flickering LED downlights in our house, especially those on dimmer switches. Dimmer switches are notoriousely sensitive to frequency variations.

I've been looking at my Multi's AC Output metrics from the VRM and I noticed that the frequency can sometimes drop as low at 48.34 Hz.

According the Multi's specs, there should be about a 1% variation on the 50 Hz output, which I calculate should only go down to around 49.50 Hz.

Can anyone tell me if this frequency variation that I am having is unusual for a Multi, or is that normal? I am wondering if this points to some type of fault?

This issue is occurring when we are running off the grid on ESS settings.

See screenshot below:


Nicholas Wessels asked
Maremotomoto answered ·

6 Answers

50Hz washing machine not running on Multiplus in Inverter mode

I have 24v DC system onboard with a Victron Energy BMS 400, 2x Li-ion HE 24/180A batteries and Multiplus 24/3000/70-50 charger/inverter.

I have a SOBA 1150 washing machine onboard (230V, 50Hz). On generator it works well, but if I start it with genset turned off and instead letting the Multiplus inverter mode deal with it – it simply does not work. Machine comes on as normal, start the program, it takes a few seconds before starting and I hear a pump running abnormally (same situation if I try running it on shore power with 230V/60Hz).

I see from other similar questions that there basically does not seem to be any good explanations, which is disappointing. I mean 3000W should be plenty (and I have everything else turned off), so I would not expect this to improve by getting an additional Multiplus.

Any thoughts?

ajaunsen asked
MichelG commented ·

8 Answers

Sub-50Hz compensation in PV-Inverter support

PV Inverter support uses frequency shifting to steer PV Inverter output on the AC branch.

This works very nice and reliable with Fronius inverters in our nstallations.

However, this frequency shift works only in the 50Hz+ range, there is never a compensation below 50Hz:


Now all devices in the microgrid that take these 50Hz as source for their internal clocks (actually quite a few do - e.g. microwave oven clocks) start to get ahead of time noticeably within a month.

Wouldn't it be possible to implement a sub-50Hz compensation in the nighttime to counter the effect that accumulates over daytime?

As soon as e.g. the Fronius switches off for the night, there shouldn't be any adverse effects to lower network frequency to 49.5 or so.

According to our measurements, the clock skew can be as much as 0.8% per day - so I'd really appreciate if the assistant had some compensation measures built-in.

PS: If I choose "50Hz" as tag, it gets converted to "EasySolar All-in-one". ???

PetaJoule asked
Guy Stewart (Victron Community Manager) commented ·

0 Answers

Alternative to frequency shifting for adjusting AC PV power?

Hello, questions- is their a victron version of Selectronics managed AC coupling instead of the current frequency shifting as this is more precise and would eliminate any clock timer issues as well..

If not something for the Victron team to look at implementing perhaps?


Drae asked
Guy Stewart (Victron Community Manager) commented ·

1 Answer

AC connect 3kW wind turbine Victron Quattro System

I have a Off-Grid Quattro 10kVA with AC Connected 3kW Fronius Primo solar inverter and 4kW of solar panels. Frequency shift is used to manage battery overcharge. System works great in summer but we are expanding for winter with additional solar, and a wind turbine. We will AC connect an additional 4kW Fronius and solar array. For wind, we are installing a 3kW 60V AC turbine that will rectify to 48V DC and this feeds to a grid tie wind controller/ inverter (China Supply) that will synch to the AC Bus. The controller will dump power to dump resistors to protect the turbine from over speed/ voltage/ frequency.

However, i am concerned the Wind controller inverter will not spill turbine power (trigger dump resistors) when the AC Bus frequency is shifted by the Victron Quattro (High batrery voltage). Logic tells my the inverter would disconnect on high AC Bus frequency and send all power to dump resistors, though I cant be sure and manufacturer info is sketchy.

My question is whether it would be possible as a back-up to use one of the quattros Programmable relays to trigger when the AC Bus frequency is shifted to say 53hz. In this way I could trigger dump resistors to spill wind turbine power when it is not needed for House Load or battery charging.

Gallows asked
Gallows edited ·

0 Answers

Unexpected AC frequency changes when set to 60Hz

I am running the Microgen Stirling Engine in an off-grid setup with a MultiPlus 3kW.

The Stirling Engine is a 60Hz-type so I have set the AC out frequency to 60Hz (@230Vrms).

This Stirling Engine has a frequency-operating-range of 60.0 +/- 0.5Hz. Our software has built-in protection: it stops the Stirling Engine when the grid-frequency goes outside these limits for more than 1 second.

We have quite a number of commercial setups with Victron MulitPlus's out there, all set up to 50Hz, all working fine.

But, when set up to 60Hz, a customer and I too, see unexpected frequency-jumps when the Stirling Engine is running. When this happens, the Stirling Engine stops and there is an error reported by the software. I have seen this error also appear in a system in my lab when the Stirling Engine is not running. There is nothing going on in these systems that would warrant frequency-jumps: there are no large loads being switched that could cause a frequency-jump.

Could there be a bug in the inverter software that only shows when set to 60Hz?

bouwew asked

0 Answers

AC coupled system Frequency lock

We have a Multiplus ll inverter/charger coupled to a Solis PV inverter. When the batteries are full the frequency rises until the Solis switches off. It then takes a long time to reduce the frequency again. The issue here is that we also have a MY PV Thor immersion controller, that dumps to the immersion based on frequency. When the PV inverter is OFF, because the frequency is still high, the THor draws power from the Multiplus and overloads it. How do I get the Multiplus to reduce the frequency sooner ? The instructions tell me that the battery voltage needs to reduce to 5.2 volts below the float setting ! In this case the float is 54 volts so 48.8 by which time the DC solar charging will be active keeping the battery volts higher.


Robert Bazalgette asked
Robert Bazalgette edited ·

0 Answers

AC coupled inverters that work with frequency shift (Solis?)

Hi Im after a list of brands that work with frequency shift to reduce output. Ive used fronius before that works well and ive heard SMA will aslo work, im wondering what other brands people have had success using, in particular im trying to find out if anyone has managed to use a Solis inverter as cost wise this would be great. Thanks

jacko asked
WKirby commented ·

6 Answers

Multiplus 12\3000\120 output frequency 45hz

Just installed a multiplus 12v 3000w to 120AC inverter charger on a boat. I'm using the mk3-USB interface to adjust settings. The inverter output frequency is set to 60hz, but its showing only 45hz on the output. This happens when running off 12v 500ah house battery bank. Please help!



LOUISE asked
Stefanie commented ·

1 Answer

Multiplus II having different frequencies in ACin and Acout1

I have the following setup:

1xMultipluss II 48/5000

1x 5kW grid tied PV inverter connected to the ACout 1 of the Multipluss II

1x BYD B-BOX 10 battery

Grid is conneted to the ACin of the Multipluss II and the grid tied PV inverter and loads are connected to the ACout 1. The Multiplus II is configured as an ESS system.

My problem is as follows: If I physically disconnect the grid from the ACin, the system works perfect. If I connect the grid to the ACin, what happens is that frequency in the ACout1 starts to change and the grid tied inverter stops inverting since frequency is out of range. This happens at any SOC of the battery and even at night when the PV invertir is not working. As long as I understand, ACin frequency and ACout1 frequency shoud be always the same, but this is not the case. Frequency variations goes from 48 Hz to 53 Hz (big changes in short time). I can also see the LEDs flikering sometimes. The main problem is that the PV inverter stops inverting due to changes in frequency. Does anyone have any idea why this is happening and how could I solve this problem. Thank you in advanced.

Julian Monedero asked
Daniël Boekel (Victron Energy Staff) commented ·

5 Answers

One Multiplus II-GX 48/5000/70-50 with Fronius 4.0 on a 3-phase grid connected system.

Hello, I plan to use a Multiplus II-GX 48/5000/70-50 with Fronius 4.0 on a 3-phase grid connected system. The 2 phases are connected directly to the consumer and the phase-3 will pass-through the Victron-Fronius system supporting Energy Storage System on one phase only . I have the next 3 questions:

1, Does the above system works fine?

2. Is the Multiplus II-GX anti-islanding certified and does exist a certificate for Greece?

3. Assuming the 3 grid phases are on. Does exist the possibility on the above system to have on the 2-direct phases 50Hz grid freq. and on the phase-3 higher ( for example 52 Hz) due to MG shifting on frequency? (This frequency unbalance would be abnormal for 3-phase loads).

Best regards,


pkorkas asked

0 Answers

Does Phoenix Multi Plus Compact 12-1200-50 support Frequency Shifting

This is an older MP until from 2009. I wanted to know whether it's possible to AC couple solar panels via a grid-tied inverter to the load side. In particular, on grid failure can this older Multi Pus be configured to control the grid-tied inverter using frequency shifting?

If this can be done then what is the procedure?


Richard981 asked

0 Answers

MyPV AC-Thor in off-grid system - settings?


the manual ( ) says that when using AC-Thor in an off-grid system frequency shifting (PV-inverter assistent) has to be activated at the Multi.

- Is this also necessary if only DC-coupled PV is used (no PV-inverter on AC-out)?

- what are the frequency settings in the "PV-inverter" assistent? Are the default-settings ok?

Best regards

e-BOX asked
Daniël Boekel (Victron Energy Staff) commented ·

2 Answers

Frequency shift too slow in the Quattro+ BYD battery +SMA SB solar inverter system


Running the Quattro with L series BYD battery (14kw) results in the battery shutting down, due to the Quattro taking extremely long time to start shifting the frequency (around 8-9 seconds from the point of BYD charging limit going to 0, utill the Quattro frequency actually start to increase)

I know the L series batteries are not current meant for the off-grid applications, but they are advertised for the backup applications, in which case Quattro has to be in position to adjust the solar inverter on time in order to prevent the battery overcurrent, should the grid fails during the day

Any suggestion if this problem can be fixed, or has a workaround ?

With best regards,

Oleksiy Frolov

fanda_eu asked
fanda_eu answered ·

2 Answers

Multiplus 48/500070 Frequency shift issue

Hi All

My system started giving an issue yesterday during peak load time (around 2.5kw load) in an island system comprised of the above Multi, an SMA PV Inverter and a Blue Nova battery. Before yesterday the system ran stable for at least 4 months continuously. (At that stage I had an issue with the Blue Nova not getting fully charged due to settings for repeat Absorption cycle - so the Multi to SMA linking worked correctly and has been for at least four years) The symptom is that the PV Inverter kicks in for around 3 seconds every about 5 minutes and is then pushed into standby mode again. The load is then supplied by the battery until it goes into protection mode ( Low Battery Light) . I checked individual cell voltages on the battery to make sure there is no hidden issue there and they were all above 3V. The same issue has happened today - I have just upgraded the firmware (2624465) and checked the PV Assistant for latest version.

The Bus Monitor shows the following:
Not in Phase
UMains (Red) 0V
IMains 0.0
Power 0 VA
UOut 229V
IOut 8.7 A
Power 1987 VA
Freq Out 49.9 Hz
Freq In ... Hz

This shows same when the load is increased to 2.5kW

I would really appreciate some assistance to what could be at fault and how do I go about resolving the issue. Thank you...

LourensJB1012 asked
Daniël Boekel (Victron Energy Staff) answered ·

1 Answer

Generator - variable output frequency issue

I have an issue with the AC output on an off grid system - 10 Kva quattro / 2 x 13.8 Kwh BYD / 6 Kwp DC coupled PV with a Stephill geni (approx 12 Kva). There seems to be a "wobble" in the frequency of the AC out when the transfere switch operates. This seems to be most prevalent on generator shut-down and causes issues with electronic equipment on the AC side of the installation. I have tried the usual "tweeks", any advice as to how I can clean up the output to prevent this ..


nic equipment installed.

ian@solarplants asked
ian@solarplants commented ·

1 Answer

Advanced system design using Fronius, CCGX, Quattro, BYD, and a Generator


After some information as to how the above components will react together in a ac coupled off grid system?

I understand frequency shifting will restrict the pv from the Fronius

How does this perform or react if there is a generator running for supplementary battery charging ?

Regards mike

mikeb asked
mikeb commented ·

5 Answers

quattro stuck at 52.7hz

isolated system with quattro8k, AC and DC coupled chargers.freq shifting from 50.5-52.5hz,off at 53hz.(SMA inverters).at end of day freq stays stuck at 52.7hz through the night, failing to reset to 50hz, battery voltage is now 49,1V 82% SOC. turning on the generator resets the freq, but this is no real solution.suggestions?

basreflex asked
Peter-ZMG edited ·

4 Answers

Two Multiplus in Parallel with one AC input at 50hz and one AC input at 60hz?

Can two Multiplus (Compact 1600s) run in parallel with one getting AC input from a 50hz generator and the other getting AC input from 60hz shore power? All other settings are the same and they are connected together on the AC outputs.

Right now they are sharing a single AC input with a physical switch to choose between Generator and Shore power input. I imagine that the 50hz Generator will not be running while 60hz Shore power is active, but it might occur. How would the Multiplus handle this? Could I set a Virtual Switch for this and maybe also set up a generator autostart/stop? I know individual Quatros allow dual AC inputs but it seems that dual Multis might work too.

Obviously the two frequencies cannot be combined, but could the shore power input run one Multi as a charger and the generator run the second Multi as an inverter/ power assist/ passthrough? If not, would the parallel Multis at least ignore one of the inputs?

The only downside to separating the AC inputs is that I assume only a Multi with an active AC input could charge the battery - essentially doubling my generator run-time when trying to quickly charge the battery as I do now using both Multis as chargers at once.

Any thoughts would be greatly appreciated!

kdagley asked
ben commented ·

2 Answers

Phoenix MultiPlus charger input frequency

I have a Victron Phoenix Multi Plus 24/3000/70 charger/inverter on my European boat which was installed in France around 2009. The data sheet states that the charger only has an input frequency range of between 45-55hz. However the manual also states that the product can operate at 50hz or 60hz. Can anyone please confirm if the charger will work ok if i plug it into a shore supply in the US of 220v at 60hz? I don't mind if it passes through 60hz but i want to be sure that it wont blow up the charger.

SYHERA asked
SYHERA commented ·

1 Answer

How does frequency shift work in a grid-coupled ESS system - my clock is wrong

I have a grid-coupled ESS system, with PV on the AC output of the MultiPlus and feed-in to the grid enabled. So I have frequency shifting enabled, in case I get more PV power than I use in a power cut situation. But normally the frequency should never shift, when the grid is working, right?

Well, my alarm clock is off ALL the time. Around 10 minutes per 24 hours, I guess.

How can this happen? And what can I do to solve this?

Dave van Dongen asked
Dave van Dongen commented ·

3 Answers

Ess system with ac coupled pv inverter how do I test if Frequency shift is working.

Completed a Victron installation ESS setup with AC coupled pv inverter SMA on the output of the inverter. How do I test if Frequency Shift is working. When does frequency shift start? At what state of Charge? Blue Nova Lithium Ion Battery installed. asked
mose answered ·

2 Answers

Quattro and Huawei PV inverter


I'm busy with an installation where we are installing 3x 8kVa Quattro's as a 3ph system which needs to act as battery backup to the property, entire property will be on AC out 2 (essential loads). There is Pylontech lithium batteries, 12x 3.5kWh.

The client has an existing PV grid-tie system with a Huawei KTL12 3ph inverter.

We received wrong information regarding the Huawei inverter and now that we started getting documentation regarding the Huawei's frequency shifting parameters we noticed that it doesn't support frequency shifting. We need to find a solution for this as the client is not allowed to feed back excess energy.

a) For now I'm considering to purchase a Huawei Smart logger and a Janitza energy meter to at least enable the zero export function on the PV inverter. The inverter will then be connected without any other loads on the AC out 1 of the quattro's so that it switches off in the event of a power failure (we cannot frequency shift so we don't want to damage batteries etc. if using on AC out 2 since the inverter will stay on at 100% output if it's getting a voltage reference from the inverters). Should this setup work? We know that the batteries will only get charge when AC input is on again since the inverter will only then switch on. The Janitza meter for inverter will be installed on the AC input side of the inverters.

b) When using a smart logger from Huawei it is possible to switch the Huawei inverter on and off with a digital input, will we be able to use the CCGX relay to switch this input on the smart logger on certain SOC levels? For instance switch the relay on at SOC 30% and off at 95-100%? The inverter will then output its production at 100% and switch off when the relay opens, and not gradually decrease its output as it would have with freqeuncy shifting, how should this affect the battery charge? If this option b is chosen we will put the inverter on AC out 2 so that the batteries can still charge in the event of a grid failure.

Both options above SHOULD be temporary solutions as my supplier says Huawei is working on new firmware to implement frequency shifting in their inverters, but that he's been asking them for over a year and they keep saying their working on it. When they eventually do the firmware update, we will change the system to a normal ESS system with frequency shifting on AC out 2 to control the inverter output.

Please mention any other workaround suggestions should there be any. Thanks in advanced.

Francois asked
Francois commented ·

1 Answer

inverter output frequency

I'm using US power (230v @60hz) and I plan to install a quattro 230v 5k with my 24v battery. Question is, even if I'm supplying 60hz to the inverter/charger from shore, can I program/set the inverter to outupt 50hz to my boat? (it's French built but now here in the US). Thanks for your help.

miami337 asked
ben commented ·

2 Answers

AC-coupled PV with Fronius PV Inverters

Hello! Is it possible to increase the speed of limiting the output power of the solar inverter Fronius in the ac-coupled system? The frequency shift settings in the ESS assistant set by default (start - 51 Hz, minimum - 52.7 Hz, disconnect - 53 Hz), but if the mains is lost and the battery state of charge is 100%, we need turn off the Fronius without delay. Is it possible to do this for example by increasing the sensitivity of the Fronius (to make the range between the normal frequency and the frequency of the shutdown as small as possible, for example disconnect frequency to 51Hz), or we have some other way to solve this problem? Thanks for your answers!

Viktor Stepanenko asked
abrahamsolar answered ·

2 Answers

Victron Quattro - disable "passthrough" functionality?

I'm in planning phase for my boat power, I've arrived in the US with a European boat and I'm working on mitigating the 50/60hz issues. So I'm planning to install a quattro 230v 5k 24v inverter/charger (then later I'll tackle getting some 110v power out of it with an autotransformer maybe). My question is - when connected to shore power (230v 60hz here in the US), can I completely disable any shore power passthrough and purely use the shore power to charge my batteries with the charger side of the quattro? This way I won't push damaging 60hz to my otherwise 50hz devices onboard?

miami337 asked
WKirby answered ·

1 Answer

What IS the relationship between state of charge SOC and AC frequency ?

As far as i can determine this isnt actually documented (properly)

(from memory the docs mention "approaching full" of something along those lines)

Also.. and to add more confusion, Ive recently noticed with a BYD lithium system that the frequency shift only happens once the batteries are reporting 100% SOC. And not before.

We are trying to configure frequency controlled switches in line with the Quattros frequency ramp on SOC

Chris asked
Paul B answered ·

1 Answer

Response time of Multiplus Frequency Control with "PV inverter support" too fast

Is there anyway in reducing the response time of the Multiplus when it increases the frequency in order to reduce the charging current with the PV Inverter Support Assistant? The problem is, that the Multiplus jumps to the set maximum frequency to reduce the output power of the Solar String inverters. This causes the String inverters to overthrottle the output. The system eventually stabilises after 30 seconds.

Any idea?

CO2blaster asked
Paul B edited ·

1 Answer

Multiplus disconnects under frequency deviation


I have an off-grid installation with 3 single-phase multiplus in parallel connected to a battery. The frequency of the isolated system can vary depending on the connection and disconnection of different loads on the system (weak grid). The problem is that depending on the rate of change of frequency the multiplus disconnects. I have noticed that if the frequency deviation is faster than approx. 0.1Hz per second (even if it is from 50Hz to 49.7) the multiplus disconnects. For slower changes the multiplus has no problem.

Is there any option which will allow the multiplus to remain connected even if the frequency deviation is not slow as long as the frequency remains within the stipulated limits? I have configured the system for a weak grid and disabled LOM, not sure if there is any other settings that could help?


egs.ust asked
egs.ust commented ·

1 Answer

Quattro Micro-Grid with External Islanding

A Grid-tied Quattro set up as ESS with Fronius PV inverter (Country Code set to 'Other - Not Compliant') on Output using Frequency Shifting. Quattro cannot be installed at grid connection point so cannot use built-in anti-islanding. Loads connected on AC Input and AC Output side of Quattro. Grid connection point is fitted with external anti-islanding relay.

When operating stand-alone as a Micro-Grid - the external anti-islanding relay isolates the grid supply - so there is no external voltage at AC Input, will the Quattro allow and regulate PV power to the AC Input as well as the AC Output?

midsummerenergy asked
midsummerenergy commented ·

1 Answer

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