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How to tell why system is dropping grid

The last couple of days my 3 phase multiplus II 5kva system has been deciding around 11am to disconnect from the grid and run off of battery/solar until around 4pm.

I presume the system is upset about grid voltage or something, but I can't actually spot any place inside the Cerbo GX that may indicate what it considers to be the problem.

As far as I can tell, the grid voltage on all phases is less than the overvoltage 10 minute average value configured in ve.config for each multiplus.

daryl asked

0 Answers

What fuse type is best for Multi-plus II?

Hi there,

Which fuse type is best for fusing the Multi-plus II? ANL, MEGA fuse, CNN fuse, other?

I imagine a slow blow fuse would be better so that it withstands short spikes of current from the inverter for short periods. I'm thinking of going with the MEGA fuse as it seems they are slow blow where as the other aren't (or they vary)? Just wanting to get some advice as to weather this would be the best option?

Also wondering which fuse type would be best for fusing each battery? I will be running 2x UP2500 25.6V Pylontech batteries.

Brandon asked
warwick commented ·

1 Answer

Multiplus flutters with coffee maker

I have a Multiplus 12/3000/120-50 Inverter/Charger that makes a fluttering sound when it's inverting about every 40 seconds when my Keurig Coffee Maker is ON.

Any ideas why this happens. TIA.

edgargw22 asked
Alexandra commented ·

6 Answers

Connect both multiplus and alternator to Argo FET input?

I currently have my multiplus connected directly to my service battery and the alternator connected to the input of my Argofet. The service battery is conencted to output 1 of the argofet, the engine battery to output 2 of the argofet and the battery of my bowthruster to output 3
In this configuration :
- when the alternator runs all 3 battery systems are charged : service, engine and bowthruster.
- when the multiplus is charging (connected to the grid), it only charges the service battery. The engine battery is charged as I connected the connnector meant for that on the multiplus directly to the engine battery.
- however my bowthruster battery is not charged at that moment.

However, I was thinking : why don't I connect the multiplus also to the input of the Argofet instead of directly to the service-battery, that way when the multiplus charges, it will also charge the bowthruster-battery?
Is this possible?

carl-dewever asked
carl-dewever edited ·

0 Answers

Suitability of 2 x multiplus 3kVA in split phase configuration to run 1 HP pump

I've asked this question through a dealer channel but no response from Victron for over a week so hoping I can get an answer here.

I have a 115/230V 1600w jet pump in an off-grid application. I'm considering using two Multiplus 3kVA units in a split phase configuration to run the pump at 230V.

The concern is whether the Multiplus system can handle the inrush current of the pump.

The pump starts and runs fine with my 5kW 240V generator, and using a clamp meter I measure 34.5A of inrush. That's 8280W of surge.

According to the Multiplus specs, a 3kVA unit can handle 6000W of surge. With two units in a split phase configuration that provides 12000W of surge.

It appears there is suitable headroom to do this but I'd like some assurance before moving forward.

Is my math correct? The other unknown is how long of a surge the Multiplus unit can handle.

And if it does handle it, will a warning be generated every time the pump starts?

Thanks for any advice!

adombek asked

0 Answers

Reset multi to factory or modified settings

I have had an issue with the SOC algorithm and voltage readings. After research on this forum I determined that it was a problem with the voltage measurement difference between the smart solar and multi. I got my SOC back up to 100% by increasing the absorption voltage to 59v from 57.6v. I didn't want to leave it this high so set about reducing the absorption voltage in the multi remotely (I do not have computer access where my solar is). So far, I have reduced the voltage down to 54v and the multi is still not recognising when the smart solar switches from bulk to absorption. I reduced the voltage again and now the multi will not start up, flashing low battery and then overload in quick succession and then switching off. Nothing else has changed in the set up which was working well for a month, SOC aside. I am assuming I have lowered the absorption and float charge voltage too low and it has interfered with another setting. Can I access the multi remotely with veconfigure even when it is off or do I need to buy a Mk3 to configure it directly? I'd prefer to avoid the $100 cost if possible...

20871pault asked
Alexandra edited ·

1 Answer

New MultiPlus-II 2X 120V doesn't show full AC load on Victron Connect

I just installed the new Multiplus-II 12v 2x120 inverter. It's working great but the data I'm seeing in Victron Connect doesn't look right. For example, I'm on 50amp shore power and with one 15k A/C running in my RV, Victron Connect shows AC Loads at 231w. When I shut that A/C down, the load stayed at 231w. When I start up the second 15k A/C unit, Victron Connect shows 1,868w. It appears Victron Connect isn't seeing power from one of the legs on my 50 amp service. Thoughts?

bertschb asked
bertschb commented ·

2 Answers

Der Batterieladestrom ist sehr niedrig der DC Strom ist dafür hoch

Laut Remoteconsole ist der Batterieladestrom sehr niedrig dafür wird in dem Bereich DC ein hoher Strom angezeigt als ob die Batterie Ladung gedrosselt wird.

es sind 3 Multiplus II 48/5000 und 12 SU2000 Akkus

Immo Messner asked
Immo Messner answered ·

2 Answers

Off grid wiring digram

Hi there,
This is how I am planning in wiring my off grid tiny house on wheels (essentially a caravan) and just wanted to see if anyone can see any issues with it? Is the earth circuit correct? Photo attached.

I haven't drawn any of the AC side of of the installation for the purposes of this diagram but I'd like to add that in addition to the connections in this diagram, I will also have:

-All the earth's from my AC loads will connect back to my negative buss bar
-A large cable (same size as battery cable) joining my negative buss bar to the trailer chassis.

Another note - The reason I have run the MPPT positive cable through the other pole on my DC isolator is because when I switch that off I want everything to stop, including the charging of my batteries. I realise I can just turn the PV isolator switches off and achieve the same result, but I want it all to turn off with the flick of one switch.

Sorry for the long winded question and thank you in advance!


Brandon asked

0 Answers

AC Polarity and Backfeed Protection on Multiplus II

I am wanting to check the Multiplus II Inverter/Charger compliance to AU/NZS 3004.2:2014 with respect to two requirements- Protection against reversal of polarity in the supply lead

Question 1

Is the Multiplus II considered an 'Auto Correction Device' with respect to Incoming Shore Power Polarity? i.e. If Shore Input is reversed will Output 1 be reversed too or be automatically corrected to match Ships Polarity? and if so will Output 2 the pass-through power also be corrected or remain at shore power polarity? Restrictions on combining power sources

Question 2

With the Multiplus II Power Assist Function does it comply with Backfeed protection requirements in particular to AS 62040.1.1 or IEC 62040-1-1:2002

mal-l asked

0 Answers

Suitable Circuit breaker between multiplus-ii and battery

Hello everyone,

I want to put a double pole MCB between a MultiPlus-II 48/3000/35-32 and 3 48V Pylontech batteries.

Pylontech recommends 25A for each Package and it supports up to 100A of discharge for each Package.

Victron states in manual:

-You must have the minimum number of battery modules to supply the inverters startup inrush surge currents that charge the capacitors when the inverter is first connected, this occurs prior to any loads being connected. For this Inverter, 2 Batteries are minimum.

-Victron recommends a 125A MCB between battery and Inverter, since its Peak power is 5500Watt (3000 AC Load + 1500 feeding in shore power)

We dont want to feed in the shore power, so only ac loads left. 3000 W / 48 V = 62,5 A. So an 80A MCB should be fine, but maybe the Inverter wants to pull more current? Maybe the stated 125A due to the startup inrush current?

I found 3 MCBs (80A, 100A, 125A) from the same series from ABB

I really would like to use an 80Amp MCB, so that the Inverter does not pull much more than the calculated 62,5 Amps.

My Questions:

Do you think the 80Amp MCB will "handle" the startup inrush current?

Does the MCB could have a minimum operating Voltage(Datasheet not found)? Is 48V fine?

Is the rated Ultimate Short-Circuit Breaking Capacity (Icu):(800 V DC) 5 kA enough for a 7,2kWh battery system?

If you have remommendations for other MCBs, please share.

Cansin Sari asked
bjorn-n commented ·

3 Answers

Victron Multiplus 2 turn on/off via modbus to save energy


i found out that after discharging the battery the Multiplus comsumes about 50-70 Watts when doing quite NOTHING. So I want to turn the MP2 off after battery is discharged and restart it via modbus when enough solar power is available.

Is there Modbus register which can do that ?

Thank you!

americanium asked
bjorn-n edited ·

2 Answers

Pylontech UP2500 and Multiplus II 24/3000 fuse sizes

I am trying to work out fuse/CB sizing for my 2 x Pylontech UP2500 batteries an my Multiplus II. (these will be linked to Cerbo GX and SmartSolar MPPT 150/100)

- Should I have a CB for each battery? Or should I have one bigger CB where both batteries join in parallel together?

- Should my circuit breaker size be the same as the max discharge current of the batteries? Or slightly lower? I know that the CB is really there to protect the cabling and that these batteries have internal over-current shut-off protection but would it be better to have CB blow rather than the battery going into over current protection?

With the Multiplus II, the manual recommends a 300A fuse which is just way to big for my battery setup. So obviously my fuse would have to be smaller than this, but how much?

Also wondering if I can change settings and put a limit on the power output of the multiplus which would help with this?

FYI I will be getting 2 more of these batteries, 4 in total soon as I am aware this battery setup isn't quite big enough to use the Multiplus II at full capacity. At the moment it will only be running small loads like lights etc.

Sorry for the long question but basically what I want to know is what size CB/fuses for batteries (and should batteries be fused individually)? And what size fuse for the Multiplus II in this setup?

I have attached the specs for the UP2500 batteries. Keep in mind I will have 2 of these in parallel. Thank you!

Brandon asked
Rob Duthie commented ·

0 Answers

Systeme coupure de decharge batterie suivant un créneau horaire (FR/ESS/EDF-HP-HC)


voila mon architecture et la suivante

- j ai un Multiplus 5Kva raccorder à une batterie plomb carbone en 48V de 440ah

- un régulateur MPPT 150/85 avec 2640w de pv

le but serai de désactiver la décharge de la batterie sur le créneau horaire des heures creuse en France de 23h à 7h.

actuellement pour se faire je suis obliger de le faire de façon manuel en allant tous les jours dans le menu ESS de mon venus Gx et modifier le SOC minium (sauf défaillance réseau) pour qu'il arrête de décharger la batterie et repasser sur le réseaux.



here is my architecture and the next

- I have a Multiplus 5Kva to connect to a lead carbon battery in 48V of 440ah

- an MPPT 150/85 regulator with 2640w of pv

the aim will be to deactivate the battery discharge during the off-peak time slot in France from 11 p.m. to 7 a.m.

currently to do so I have to do it manually by going to the ESS menu of my venus Gx every day and modifying the SOC minium (except network failure) so that it stops discharging the battery and going back to the networks

thank you

baptiste bodier asked
Stef answered ·

5 Answers

Multiplus II and CT Clamp Error 24

We are experiencing issues when using the external CT clamp on the Multiplus II 5000 inverters.

We have recently installed around 15 systems with the external CT clamp and on approximately 4 or 5 of them we are experiencing Error 24 occasionally when grid power returns after a grid power failure. We are not using the second output of the inverter. We are running ESS.

From the Victron website:

"Error 24 is raised when a Multi or Quattro detects current flowing through the back-feed relay during a period when the relay should be open."

The error seems to occur more often when there are inductive loads like swimming pool motors connected to the non essential loads between the CT clamp and inverter. It also seems to occur more frequently the larger the non essential load is. From numerous tests on these sites, when we unplug the CT clamp the issue no longer occurs.

We have confirmed that are no issues with neutrals etc. The issue seems to be related to the surge in current through the CT clamp when the grid power returns and all non essential loads start up. We have tried multiple Grid codes as well as disabling LOM detection but nothing seems to lower the systems sensitivity when grid power returns.

garthvs asked
Daniël Boekel (Victron Energy Staff) commented ·

2 Answers

Victron Wiring Example - MultiPlus II with Lithium, Cerbo GX and new Lynx Smart BMS

Victron Energy produces loads of great schematic drawings to help you plan your wiring. This is the first in a series of schematic drawings and it features the new Lynx Smart BMS together with the MultiPlus II with two 120v circuits. You can see there is solar and alternator charging as this is would be a complex install for an RV in the US for example.


Here is a link to the full-sized pdf.

Jono (Victron Energy Staff) asked
rick0 commented ·

0 Answers

Do batteries take any load at all when mains plugs in?

I have 2 Pylontech batteries that are wired to a SmartSolar MPPT and a Multiplus II.

It's my understanding that with the Multiplus II, when there is no mains connected (no AC in) the required current the inverter needs to run the AC loads comes from the batteries. Then when there mains are plugged in, the current for the AC loads comes straight from mains through the Multiplus II. So no load is put on batteries or MPPT while mains are plugged in. Is this correct?

Thanks in advance!

Brandon asked
warwick answered ·

1 Answer

Multiplus II 48V 3000W - Damaged Interference Suppression Capacitor






Please help me understand whether replacing the capacitor MKP62 305~X2 225K 40/110/56/B can restore this inverter. The capacitor was damaged by a short circuit on AC IN during heavy downpour accompanied by several lightning strikes.

The adjacent toroidal inductor sparks and the inverter goes to error mode.

The fuse is ok and the line has continuity.

Any top and underside PCB photos of undamaged inverter for reference will be highly appreciated.

Sample photos attached.




lawrence-1 asked
wkirby answered ·

2 Answers

Mobile trailer grounding

I am building a Tiny house on top of a steel trailer. My tiny house on wheels will be mobile and off grid with batteries charged by PV array. Will have the occasional plugin to a Generator for extra charging if need be.

My question is how does the ground circuit work in this scenario.

- Does the earth wire from the inverter, MPPT, PV panels grounds, battery casing, AC power outlets, lights, trailer frame, etc all join to a copper steak that I can drive into the ground when I park the trailer?

- Should the battery negative also be joined to the earth buss bar?

I have attached a rough diagram of how I think the earth circuit would go (earths in green). Could someone please let me know if this looks right. I quickly drew this diagram mainly for to show the earth circuit so I do apologise about the rough nature and any symbols that aren't quite right.

Thank you!

Brandon asked
Kevin Windrem commented ·

1 Answer

Split Phase Setup in 3 Phase Network

Dear All,

is it possible to create a Split Phase System connected to a 3 Phase network?

First Multiplus 2 connected with AC in on Phase 2 and second Multiplus 2 connected with AC in to Phase 2. ESS with Feed Back enabled.

AC Out only of first Multiplus for some loads used.

All Neutrals connected like it is needed in manual.

Technically it should work, but is it considered by Victron Energy Software?

Thanks a lot!

dennis asked

0 Answers

Battery Switch ON/OFF 275A

The Battery Switch ON/OFF 275A 12-48V

Can i use it in a 48V system with a Multiplus II

jens-due asked
marekp commented ·

1 Answer

Can two Separate Multiplus II inverters supply different loads while using the same battery bank and still be connected and monitored on the same Network/GX Device

We have a client that has an existing system with a 3kVa Multiplus II. The client recently added a flat (garage transformed for the kids) and they want to add another inverter to assist with the load to this flat/garage.

1. Can both Multiplus units be connected to the same battery bank but supply different loads? (one the house and the other one the garage?)

2. If connected in this way, can both units be connected to one GX device or will both have to be separate in such a case with their own gx devices?

And a bonus question for silliness: Can two separate systems be connected to one battery bank? (Especially now that DVCC is "Regulating the usage of the battery"?

I know the safe connection will be to parallel them and to allow them to supply both loads as "one", but is this configuration possible? The client asked and I do not have an answer for this. I know there is similar post to this but not one that answers the question.

schalk-1 asked
marekp edited ·

3 Answers

Multiplus 2 AC-1 breaker sizing

Hi everyone,

My house's load is 30A. I am installing a solar system and I am thinking of a Multiplus 2 3000VA which should be enough.

I want all my house to be connected to the critical load output, however I have few concerns below.

- If my load is 25 and PV's are supplying 20A, the grid when on will compensate the rest 5A needed. correct?

- What will happen if my load is 20A and suddenly the grid goes off? Knowing that the inverter output power is 11A (2400W), what will happen then?

assaadeldleptany asked
assaadeldleptany commented ·

1 Answer

Battery protect 220A, voltage drop

Have a BP 220 unit. IN-pin connetcted to plus on Li bat with fuse inbetween. Also connected to IN-pin there is a multiplus and a smart solar connected.

When I add load through the BP I got voltage drop when turning on smal consumers from 13.4 to 12.9v (lamps). When using bowthruster och windlash the system shuts down totaly.

If I remvoe the BP everything works fine, what is the problem?

I have bought a second BP and I got the same behaviour with that one.

Best regards


kim-hilding asked
kim-hilding commented ·

2 Answers

Compatibilité Générateur et Multiplus II


Mon motel est connecté au réseau électrique et je dispose de deux GE de 30kVA et 20kVA respective qui sont sollicités selon le besoin avec un démarrage manuel.

Je souhaite ajouter à l'installation existante 24x325Wc en deux sous champs couplés à 2 MPPT 250/100, 28kWh de stockage, 3*3kVA Multiplus II en configuration triphasée .

1) Pourriez-vous me dire à propos de mon schéma câblage coté AC, si mes équipements et les utilisateurs seront suffisamment protégés de tous les risques possibles (contacts indirects, surcharge + court-circuit + défaut à la terre ) ?

2) Pour la protection AC-in des Multiplus II que j'ai choisi , Victron préconise 32 A pour chaque Multiplus II. La configuration triphasée permettra t-elle de foisonner les courants entre phases? ce qui en réalité me permettra d'avoir sur chaque phase plus de courant?

3) Mes GE de 30kVA et 20kVA sont assez vieux, est-il possible de piloter automatiquement la marche et l'arrêt avec la BMV700 ou le CGX?

4) Avec ces onduleurs on va « rétrécir » la puissance max disponible en tête de TGBT : 32 A avec SNE/GE et 32+13=45 A avec SNE/GE+Victron, alors que jusqu’ici ils étaient limités à 50 A (disjoncteur en tête du TGBT). Quelles mesures devrait -je prendre?

Merci pour vos réponses


configuration triphasé des MultiplusII et protection



energy-eden asked
Thierry Cortassa (Victron Energy Staff) answered ·

1 Answer


Generator and Multiplus II compatibility


My motel is connected to the electricity network and I have two GEs of 30kVA and 20kVA respectively which are requested as needed with a manual start.

I would like to add to the existing installation 24x325Wp in two subfields coupled with 2 MPPT 250/100, 28kWh of storage, 3 * 3kVA Multiplus II in three-phase configuration.

1) Could you tell me about my AC wiring diagram, if my equipment and users will be sufficiently protected from all risks (indirect contacts, overload + short circuit + earth fault)?

2) For the AC-in protection of the Multiplus II that I have chosen, Victron recommends 32 A for each Multiplus II. Will the three-phase configuration make it possible to increase the currents between phases? what will actually allow me to have more current on each phase?

3) My 30kVA and 20kVA GEs are quite old, is it possible to automatically control the start and stop with the BMV700 or the CGX?

4) With these inverters we will “narrow” the maximum power available at the head of the main switchboard: 32 A with GRID/ GE and 32 + 13 = 45 A with GRID/ GE + Victron, whereas until now they were limited to 50 A (circuit breaker at the head of the TGBT). What precautions should I take?

Thank you for your help




energy-eden asked
Matthias Lange - DE answered ·

1 Answer

MultiPlus-II GX 48/3000/35-32 compatible to LG Chem RESU 6.5?

Hey here,

I'm wondering if the MultiPlus-II GX 48/3000/35-32 can be used together with an LG Chem RESU 6.5. Especially I'm interested, if this is combination is certified or tested by anyone.

As can be read here, the combination of MultiPlus-II and a LG Chem RESU needs a GX interface to trigger the keep-alive via CAN-bus at the RESU. So I'm wondering if this can be done by the GX-version of the MultiPlus-II, so that no extra device is needed to be installed.

Thanks in advance!

phtr asked
Matthias Lange - DE answered ·

2 Answers

Multiplus-2 does not appear on victron connect

Hi all,

I am trying to update the firmware of my easy solar-2 GX 48|3000|35

I am using CAT5e (connected to one of the VE.bus ports) and Mk3 to USB to connect on my windows computer. When I open my victron connect app on windows laptop, on the device list page, in LOCAL section all I can see is EasySolar-2 and not multiplus 2.

What do I need to do for it to appear on victron connect?

I also looked online and found old method of firmware update using veflash. I can not find where I can download veflash anymore?

Please help

mo-awais asked
Paul B answered ·

1 Answer

Multiplus not bulk charging

Hi. I have a new install MP2 3kVA with victron gel batteries (4 x 220AH in series).

I did an initial discharge test down to what the system believed was 70% or 48.9V.

When I cut back power, the charger went straight into float, not bulk.

It has slowly charged back to 85% and is now in storage mode.

Any ideas why it would not have bulk charged?

Should I just run another (longer) discharge cycle and see if it corrects itself?

nickdb asked
heinvdb commented ·

3 Answers

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