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multiplus in parallel

Power Assist Issues

My installation consists of 2 Multipluses 12/3000/120 (in parallel), Lynx Smart BMS, Cerbo GX, 4x Victron Lithium 330ah batteries., and 4 Smart Solar 100/50 with all DC loads on a SBP. All components have the latest firmware. This is on a sailing catamaran.

After months of flawless performance, I’m experiencing some intermittent strange behaviors that are occurring more frequently with the power assist capability of my system. I get slightly different behaviors if I’m on shore power vs generator power.

  1. Shore power: Occasionally I’ll wake up to see my batteries are somewhat depleted as the system is using assist unnecessarily. You can see in the first picture where my Multipluses are accepting only 1185W of power, but my AC loads are 1918W. My input limit in this case is set to 25amps as I’m currently on a 30amp shore pedestal. Additionally, I’ll observe that the reverse polarity light on my panel glows slightly brighter with increasing loads. NOTE: When bypassing the Multipluses, or while solely inverting power, the reverse polarity light is completely dark.


  2. Generator Power: After degrading performance which started similar to what I’m experiencing with shore power above, the system has mostly stopped accepting generator power, and I get a fault. See picture 2. I found I can sometimes trick it by turning off all AC loads prior supplying generator power in. But I’ll often get the little triangle error on the device list page of my cerbo. However, I don’t see any actual notifications for my multiplus. I also experience glowing reverse polarity light on my panel. In the tricked mode, none of my air con units will start (even the 8kbtu). In my troubleshooting, I removed the ELCI breaker from the output of the generator and it appears I’m back to flawless performance. ABYC codes require an ELCI, so I’d like to return it to service.


Has anyone experienced similar error conditions? Could it be that my Generator’s output ELCI has failed and is causing the inconsistent behavior? Could I have some other grounding issue? Like possibly Ground Relay issues?

brucevanderbilt asked
trevor-bird answered ·

3 Answers

Easy solar and Multiplus in 3-ph or parallel

Hi! Easy solar includes Multi plus, MPPT and CerboGX in one package.

Can a similar multi plus be used for a parallel configuration vith Easy Solar?

Is it possible to use Easy Solar and some Multi Plus to create a 3 phase configuration?
Thank you for answer.

zhurkinva asked
zhurkinva answered ·

2 Answers

Solved: Dual Multiplus-II with non symetric Output and ESS missing Grid-Setpoint

Hello all,

i have a Problem with 2 MP-II 3000/48/32 in parallel Setup, on Phase L1 in 3 Phase Grid.

EM24 Grid Meter in Place.

ESS is missing the Grid Set Point by at least a few 100 Watts.

Power-Output is not the same on both Inverter,

Maybe 1/3 generated from the older Inverter and 2/3 of Power from the newer Inverter, measured on the AC Side.

Both MP-II 3000 run fine in Single Inverter Configuration with ESS, configured parallel ESS is not usable, same Wires.

Both Devices are the PMP482305010 , the first one bought April 2021 and the new Unit from Feb. 2022.

Firmware on both Inverter is up to date, 497.

The Inverter wnhere bought by different Distributors, which one to contact ?

Kind Regards,




kai-gt asked
kai-gt edited ·

1 Answer

Multiplus 1 - Parallel setup 3 inverts - Chip version - .HEX and .VFD

Good Day,

Im installing my Multiplus 24/3000/ 70-50 units in parallel . I noticed now that 1 out of the 3 units have a slightly different chip

All 3 unit can go up to the same version 4XX firmware.

Will the .HEX chip prevent a successful setup ?

Inverter 1 - 2610152.HEX (PMP243021010)

Inverter 2 - 2610158.VFD (PMP243021011)

Inverter 3 - 2610158.VFD (PMP243021011)


denzel asked
wkirby answered ·

1 Answer

Question to Wiring Guide / wiring 3-phase system (3x Multi) via busbar to 2 batteries


I have designed a three phase system (3x multi plus, 1 with GX) that are connected to a bus bar and then to a battery rack (10 kWh total) as shown below. The cable wiring from each MP2 to bus bar is 2m, from the bus bar to the battery < 1,5m. According to the manual, I chose for the 48/5000/70s 70mm² wiring.

Now I encountered the following issue during installation: the batteries use proprietary cable connectors that were supplied with the batteries but they can only fit 35mm² wire. I also tried 50mm² wire but it doesn't fit. As shown in the picture, I am already using 2x35mm² for each pole (1 to each battery).

According to wiring guide the cables running from bus bar to battery should be thicker (or equal) gauge than the ones running from bus bar to the MP2s. Given the short distances, does it really matter here? Obviously I could reduce all cable sizes, but that doesn't seem to make sense to me. What is the issue with the battery cables being thinner at 35mm² (given that is the recommended cable section from the manufacturer)? What can I do?

Many thanks!!!


krouink asked
bhi answered ·

4 Answers

2 x Multiplus 2 48/3000 (parallel on phase 1) in ESS: grid setpoint not reached


I am using 2 x Multiplus 2 48/3000 (parallel on phase 1) in an ESS configuration with a Pylontech Battery US2000b+ (9.6kwh total) and a Venus device with EM24DIN. There also is a Fronius Symo 15-M AC coupled inverter with 10kwp PV connected.

All this in Germany on a 3Phase grid ("Schieflast" is avoided by other measures).

The second Multiplus was only installed yesterday, since then I observe that the grid-setpoint is never reached, there is, especially on battery, always a much greater consumption from the grid than set.

Grid Setpoint is set to 10W, true average consumption from the grid is almost 200W all through the night. As I stated: this is only true since the installation of the second multi.

If I adjust the setpoint to -200W, consumption drops but as soon as the solar kicks in during daytime I am exporting more than I want.

What could be the reason?

Thank you very much!


jfleissner asked
kai-gt commented ·

1 Answer

Parallelling a three-phase with a set of Multi's and a set of Quattro's

So, I don't want to complicate my life but here is the scenario:

Three phase installation

Installation already has 3 x Fronius Primo and 3 x 5kVa Multiplus (not the 2)

My client needs to expand. Is is a rural application but grid feedback is also required for export income.

Presently the Fronius have all the solar modules. I need to add more capacity to the Victron and want to add 3 x Quattro's and Mppts for DCPV. I would like to avoid removing the Mulitiplus's.

I need the Quattro's for the 3-phase generator input

Could one parallel the multi and the Quattro's

Is this asking for trouble? Surely we are adding two parallel supplies? Is the limitation on the VRM ?

Lyndsay Cotton asked
marekp edited ·

3 Answers

3 x Multiplus II parallel error 17

I have 3 MULTIPLUS II in parallel and can only get 2 to operate, whenever I connect a particular unit I get error 17.

The dc cables are all the same length and type and the RJ45 cables are all purchased and new. 2 units work fine in any position but the 3rd fails in any position. They are all running the same firmware (was 494 now 497, no change to behaviour)

Any ideas for what I can check next?



max-ansbro asked

0 Answers

EasySolar , installation en triphasé

bonjour , récemment inscrit, merci de votre accueil prochain à cette question :)

j'ai actuellement 3 easysolar 5000 en 48v pour trois circuits indépendants en mono 230v

chacun a son installation avec son jeu de batteries et ses panneaux

je souhaiterais réunir tout ça et passer l'ensemble en tri-phasé

cette installation est off-grid, il n'y a pas d'arrivée externe

j'ai vu des videos avec des multiplus mais pas des easy solar,

faudra t il condamner certaines parties de deux d'entre eux (color control ...)?

si quelqu'un a déjà fait un montage ?

merci de votre aide

sneval asked

0 Answers

PV Inverter dropping from CCGX, batterys charging - Rewired and new CT same issue

So basically what happened was my pv dropped off my ccgx about 2 month ago. I isolated the mains a few times and put it back on and there it was back on my screen. Until this stopped working. Then I thought the Carlo Gavazzi energy meter was the problem so I brought a new AC CT sensor specifically for the solar.

Got this working last night it detected my panels it fed them into battery it discharged them then I woke up this morning to check it was working. and no something happened overnight it dropped the meters 7am this morning. FFS sick of this now really need some support on it.

Any help appreciated

Dale asked

0 Answers

Parallel Multiplus in ESS not accepting the grid

New install consists of two Multiplus 2 (5000W 48v) with six Pylontech US3000 and Cerbo. Output will be from AC Out 1.

Configured for single phase parallel operation, with ESS assistant set up on each inverter. Starts up and runs correctly with both AC outputs connected via equal length cable.

Problem starts when i try to connect the grid to AC In. I have used two equal length cables to take grid power to each Multiplus AC in, but applying grid power causes inverters to slowly cycle through connecting and disconnecting, or at least a sequence of relay cluncks that continue to cycle with a variety of flashing LED front panel lights. Obviously something is wrong.

Q1. When using this setup, ie parallel Multi's and ESS, should grid be connected to both Multi's AC input or only to the Master Multi?

Q2. If I have connected the grid correctly, any suggestions where to look to get the system working correctly?

Thanks in advance

philr-1 asked
philr-1 published ·

12 Answers

Inverter Parallel Compatibility

Hi Guys,

With different version of the Victron Multiplus 1/2 out now, Is there a compatibility chat-table of what can work together ?

I understand previously both devices must be identical ? is this still the case?


denzel asked
Stefanie answered ·

1 Answer

Restrat when battery is fully charged with grid without grid feed-in

Hello. I have problem with this. (three phase) Configuration is 3x Multiplus II 3000W 48V, GX modul, 1x MPPT regultor 150V/85 and 1x MPPT regulator 150/70, 1x VictronSMARTHUNT 500A with 16x lifepo4 battery 300Ah. BMS is JIKONG B2A24S150 and current senzor. With ESS configure. When battery is fully charged and connect with GRID system fall down and multiplus II is restart When enegry is in FV panels. I disabled feed-in is disabled. Grid metering is "Inverter/Chrarger" If I use off-grid everything is corect don´t resatart. Have you ever solved this problem.

Tomas asked

0 Answers

GX or not GX

I'm planning to install a new system with a multiplus-II 5000 but I think that power will be not enough within some time (in a 2 years time frame). I'm planning to pass to a parallel configuration in two years. I will be able to add additional PV modules and batteries (Pylontech) and use more power and also to have a level of redundancy

Considering that is possible to have only a GX device what do you think is the better option:

1. Install now a multiplus-II GX now and then install a second multiplus-II GX, disabling the GX part

2. Install now a Multiplus-II and a Cerbu GX and the install another Multiplus-II

3. Install now a Multiplus-II GX and then, in parallel a Multiplus-II NO-GX

4. Redundancy is not required, use a Multiplus 8k or 10k now and a Cerbu GX and upgrade only batteries and PV modules


Kind Regards!


blackstar asked
Jason - UK commented ·

4 Answers

Multiplus-II 8kVA and 10kVA in parallel

I believe the 8kVA and 10kVA Multiplus-II's cannot be paralleled. Will this be fixed with a future software upgrade or never?

If it will be possible in future, then when?

energy asked
Matthias Lange - DE commented ·

5 Answers


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