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Inverter mini power cut / power loss for seconds / Ups not working

Good day,

I have a 25kva Generator running a 10kva Multipluss II with 10kwh of battery capacity.

the system has been running ok unto Christmas, (4 weeks)

I have tried to replicate it by starting and stopping the generator and under different loads,

however it seems to happen without any 'Trigger'

I have attached the Excel file showing when the power blip happens i have a loss of data on the Logging on VRM Download.

the generator is used to power the home and when the builders come in the site as well,

however it is only connected via a 32a plug, (and its been working with a current limit of 30a set)

i have the issue sometimes were the ac input is not accepted, even when it is at 52hz and at 233v, however i have linked this to when i do a ve config upload, i have to re-set the ve bus to not have this issue.

batteries are bms connected to the cerbo, and they don't have any issues i can see, I have tried to run the system without the bms connected as well. and have no issues except the 15s power blip, which is still random,

any help would be appreciated, (the attached is all i have been able to get to prove it happens, prior to this I didn't really know if I believed the client)

time today 08.01.23@ 15.41

gen snip 1.PNG

gen snip 2.PNG

gen snip 3.PNG

gen snip 4.PNG

Matthew Deal asked
nickdb commented ·

2 Answers

Multiplus 24/1200/25 switching between charger and inverter

I have a Victron Multiplus 24/1200/25 hooked up to a set of series parallel Blue Nova BN13V-108-1.4k lithium iron phosphate batteries. I also make use of a Victron Battery Monitor BMV-702. I use the Multiplus as a backup/UPS to provide power during power outages at my house. I observe the following behaviour of the Multiplus:

• When AC power is lost, the Multiplus switches to the inverter and provides power, as expected.

• When the AC power is restored, the Multiplus starts charging the batteries, as expected.

• After a few minutes, the inverter will kick in again, and the fan will spin up.

• After a few seconds, the fan turns off, and the charger starts charging the batteries again.

• After a few minutes, the inverter and the fan turn on again.

• After a few seconds, the charger turns on again, but this time the fan remains on. The charger and fan remain on until the batteries are fully charged.

• Once the batteries are charged, the fan stops, and the charger goes into absorption mode.

This pattern consistently repeats itself each time the AC power is restored. This happens even if I unplug the Multiplus, and plug it in again after some use (ie, without an actual AC interruption from the utility). Is this pattern of switching between charging and inverting expected each time the AC power is restored? I would expect it to switch to charging only once, once AC power is restored. If this pattern is not expected, what could cause this?

frodob asked
frodob answered ·

3 Answers

Victron MultiPlus II - ESS - Irregular Transfer Time - Appliances switching OFF

Hi All,

Our company has executed over 300 Victron installations and just recently we are encountering a phenomenon where a few systems are not transferring seamlessly from a grid-connected state (ESS) over to the Inverter upon failure of the AC Grid supply.

Victron MultiPlus-II including MultiPlus-II's in parallel
Victron Cerbo GX
Carlo Gavazzi Grid Meter (ET112 or ET340)
Grid code: NRS-097-2-1 (South Africa)
LOM: Enabled (Type B)
Assistant: ESS
Battery: Freedom Won LiTe Home or Pylontech
Firmware: 494, 495, 496, 497

The VRM advanced section does not detect a drop in the AC-Output voltage, however the phenomenon is clearly evident on site where the lights, WiFi router, TV and other plugs will drop and recover - having to reboot as a result of the duration of the power interruption.

We do not have the equipment to measure the output and confirm the transfer time but it is my understanding that the MultiPlus-II is supposed to transfer within 20ms to justify it's proposed UPS rating/capability?

Has anybody got any insights into this problem?

Thanks in advance.

Nicholas Herbst asked
nickdb commented ·

1 Answer

Slow UPS on Multi ii 5

Hi guys.

Installed a new Multi ii 5 yesterday and UPS is not working as it should. Power goes down for a second before turning on.

UPS function is enabled.

RSA Grid selected.
LOM enabled

Firmware 481.

10kWh FreedomWon installed.

Any idea what might be causing this?


mauromartini asked
Matthew Walsh answered ·

4 Answers

UPS design with Victron

I had Victron for short time, but then was forced to dismantle the units and replace with other system. There is no Victron support in my country and also for this reasons installers does not want to install Victron. As my current system is significantly underperforming (but reliable) I'm searching to have again power that is closer to my needs, but with reliability of current solution.

Maybe someone able will be able to help. I would like to build UPS like install with battery, ideally charged by solar cells. There is cca 8kWp on the roof, battery I would like to have cca 10kWh and maybe also with generator. I need 3phase 240V minimum 5kW per phase.

Known prolems with Victron units:

1. Random shut down with "unknown error" message and also shut down all other units

2. By shutdown grid is disconnected

3. Long transfer times when grid fails causing shutdowns

4. Discharging battery under minimal SOC

5. Extra loud (mainly during night when charging batteries depleted by point2) on full power

I heard that Victrons are used on boats in large scale. How it is done that unknown error does not power down whole ship.

What I had was 3x 5kVA multiplus, BYD battery, 2x MPPT charger, very powerful but not reliable

What I have now is GoodWe 10kW + Pylontech, very reliable, but greatly underpowered and no scaling possible

peter79 asked
Matthew Walsh answered ·

2 Answers

Can I use a Blue Smart IP65 12/15 in an online UPS setup?

Hi. We're currently experiencing some hectic "loadshedding"/planned power outages (few times per day for 2-4 hours at a time) and I'm trying to make my backup power solution a bit more convenient.

Initially manually switching my workstation + internet devices over from grid power to my battery+inverter setup was fine, but having numerous loadshedding slots every day is annoying and I don't think it's the best for these devices to lose power and start up all the time.

I was thus wondering if I can use my Blue Smart IP65 12/15 charger as a power supply for my workstation permanently. So basically creating an online UPS solution (charger => battery => inverter => appliances).

Regarding the power supply function, yes I understand that it has a power supply function, but that's not my question. I want to only use the charger function and not manually switch between charge and power supply functions when needed. That's off topic but just in case someone wanted to mention it ;)

I'm more concerned about the longevity of the charger if it's supplying power 24/7 rather than simply charging the battery and then going into float.

I have also looked at more permanent solutions made for my exact problem (for ex. the multiplus range), but that's not an option right now as I'm in a rental place where I cannot make any permanent modifications, not to mention that it's way outside my budget :)

I also thought of the situation where once the power gets back on that some power from the charger will go into the battery and some to my devices, meaning the battery is not being charged as fast as it might have been. That's also a different problem.

I noticed it gets quite hot during the bulk stage, but I have a fan moving some air over it to help cool it down for what it's worth.

So is it okay for this charger to be spending a lot of time in high-current stages (will most likely spend majority of time in the float stage with about 5-10A current)?

wscholtz asked
wscholtz commented ·

1 Answer

Any way to program relay 2 to disconnect load after some SOC value?

Hi guys,

I have programmed a system with 2 Quattros of 10kW to obtain a 120/240 split phase system, also 1 Cerbo GX and 4 MPPT 100-250 controllers, and 20 kWp on PV power, and 30 kWh on storage by pylontech, an 20kW on propane generator.

The issue is that in relay 1 I have connected the start/stop functions of the propane generator.

Additionally, and the reason for the question is that the generator could not start due to various faults, such as an empty propane tank or the starting battery does not work or someone forgot to put the system in automatic mode,

so, as an additional method, it is required that when a low SOC level (something like 30 - 40%), relay 2 be programmed to disconnect the load and only leave the essential load running (like a refrigerator and a modem).

I understand that I require a contactor previously wiring to separate the loads.

thanks for your time guys,

Greetings from Baja California Sur, Mexico.


iruizh asked
wkirby commented ·

2 Answers

MultiPlus 12/1200/50, 12/1600/70 questions

Hello. I'm considering buying MultiPlus 12/1200/50 or MultiPlus 12/1600/70 unit to use as a solution for a power outage and also as UPS, maybe with adding a solar mppt controller in the future.

Before that, I'd like to clarify a few questions.

1. I'm going to integrate the unit into my house wiring with a switch to add or remove multiplus from the wiring if needed.

I know that the unit can passthru grid energy when it's available but the question is - can it passthru power greater than its own, I mean if we are using multiplus which handles 1200w but there is no power outage and it works in passthru mode with my power consumption let's say 4000w?

2. I'm going to use some sensitive equipment like a pump for floor heating and a gas boiler, they require clean sinus output and stable voltage. If we are using these devices in passthru mode using grid, does it mean that multiplus can handle grid issues and replace the power source smoothly?

3. I'm considering using lifepo4 batteries with that unit. Is it fine for that? And if the battery has a max charge current 50A and my multiplus unit is 12/1200/50, that means that 100Ah 12v battery will be charged in 2 hours with that device, but if I'd like to add one more battery with similar specs to double the capacity that means it will be charged in 4 hours. Am I correct?

In that case, should I consider a 12/1600/70 unit if I'm going to use two batteries in parallel?

boringdice asked
daver-1 edited ·

1 Answer

12v UPS battery display only unit with phoenix and multiplus range

Hi All,

I'm looking for a solution where one can add a basic display only unit on a 12v battery connected to a phoenix or multiplus inverter/charger

hdp asked

0 Answers

Disable UPS Function with ESS (on EasySolar-II GX)


I'm using a grid-connected EasySolar-II GX 24/3000 with grid meter, solar, SmartLithium battery and setup as ESS configuration (all with latest firmware). Everything in the system works fine, however..

In previous topics I read about humming/buzzing noise coming from the inverter with almost zero loads and connected to the grid. The noise is not so loud, but when I go to sleep at night (and ambient noise is quiet) this buzzing sound starts to get very annoying. It is my understanding that specifically the UPS function ensures constant activity (synchronization) of the transformer with grid and AC-out.

In the system I use the UPS function is not necessary and would therefore like to disable it. However, in VEConfigure (3) the UPS function checkbox is not visible. This may have to do with the ESS configuration (and UPS is enabled by default). Is there a way to disable the UPS function in this ESS configuration?

At the moment I have solved this buzzing 'problem' (I know, it is really just a physical property of the toroidal transformer) by just disconnecting AC-in and I prefer not to do that. Thanks in advance.

Dennis asked
Alexandra commented ·

1 Answer

3x10kva output dips on grid connect/disconnect

We have 3x 10kva Quattros in a 3phase connection working with a Fronius Symo 8.2-3-M inverter. There are multiple loads (aircons, PC's, wash machines and more) that reset every time a grid failure and grid connection is made (load shedding). We have never seen this before, any help?


  • UPS function is ticked
  • Low Disconnect was recently changed to 205v and reconnect 208v (as advised by some)

janjan asked
janjan edited ·

1 Answer

UPS connected to multiplus II starts event that multiplus is working

This weekend I saw my Trust UPS connected on AC OUT 1, switching to UPS mode a few times. The UPS switched back to AC withing the same minute.

What could be the cause for this ?

rns asked
rns answered ·

2 Answers

UPS Function Multiplus II failed today on overvoltage event

As the title mentions.

Today we had a major power grid failure where I live in the Netherlands. This caused the voltage to rise to abnormal values before completely failing.



You can see that it disconnected multiple times from the grid due to under voltage. When it disconnected from grid for over voltage, it turned off shortly after switching to "inverting".

The power in the house (behind critical) turned off, and I right away headed over to the victron equipment. It was in the following alarm mode:
VE.Bus Error: VE.Bus Error 10: System time synchronization problem occurred

In the manual its mentioned as not a real error, usually during system reboot. However, there is no other alarm created before that one. What caused the system to reboot?

The idea is that victron acts as a UPS, it works fine when I disconnect the grid via the breakers. But when an actual situation occurs where it's needed, it fails to protect completely, at least in the UPS part. It probably actually did protect my house from the over voltage that in my sister's house caused some electronics to break.

Do I have too high expectations of the system?

Additionally, my transfer switch settings, are they too loose?


Marco Nijholt asked
Marco Nijholt edited ·

0 Answers

MultiPlus PC backup Inverter size and load

I want to make a backup system for my PC+Server but i really don't know what size inverter i should chose.

My normal load is 450W-550W but when everything is on max usage it's around 900-1000W. So i'm wondering if a 800VA multiplus would handle being overloaded to around 1000W for about 10 seconds

xpatrik asked
xpatrik commented ·

1 Answer

Does the Victron system perform full UPS function?

I am new to this and my system was only commissioned at my holiday house a few weeks ago. My setup currently runs on solar all day (unless the weather is bad) and battery all night (unless the battery drops below 40%) other than 300 watts per hour of grid power. If the gird fails, my circuits which are designated as critical loads will run from the battery and 40% of the battery will give them around 8 hours. It appears to me (based on a few weeks of monitoring) that the system will be on “grid only“ power for about 10% of the time (presumably more in winter) and probably increasing to about 60% of the time when we are actually using the holiday home.

My understanding (and I may be wrong!) is that the system will protect from poor quality power (surges, high voltage etc.) from the grid when the battery is in use and when the solar is in use but not when the power consumed is “grid only”. Assuming this is correct, is there any way to protect the critical loads from dirty power all the time using the system or does one need a separate stand alone UPS?

Thanks in advance from a real newbie!

sa-victron-user asked
Henrik answered ·

4 Answers

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