question

theklaas avatar image
theklaas asked

2x Multiplus setup - one per phase

Hello

I have a few question about Victron setup. And hopefully someone can help me.


At this moment I have a 3 phase power connection to my house. I don’t use 3 phase equipment.

At phase 1, a Victron multiplus 24/2000/50-30 is connected. This Victron will power some groups to my house. A PV is connected on the AC-OUT. The 1:1 rule is followed.


For management I have a Victron Venus and BMV-702 to control my 2 batt (12v/220AH). The SOC is managed by victron venus and not by the multiplus. as assistent i use the ESS.


Question 1:

Is possible to add a second Victron multiplus on the second phase. So this unit can also power some groups that are connected on phase 2. So this is not a parallel or 3 phase configuration. There will be no equipment behind the victrons that will use both phase.

Is this possible? And if so, is allow to use a different model like multiplus-II for example.


Question 2:

Is possible to connect both Victron at the same battery set. Of course the DC power must be the same.

I wondering about the how the charging will take place, or will the Victron Venus control this process on both victrons.


Question 3:

The last one…but I think already know the answer.

Is there also a 1:1 rule for mppt that is connected on the DC site of the victron multiplus. I read on other post that there is no power limit. (https://community.victronenergy.com/questions/16442/rule-11-pv-power-plant-victron-inverters.html)

Multiplus-IIMPPT ControllersMultiPlus Quattro Inverter Charger
4 comments
2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

dayandnight avatar image dayandnight commented ·

Hello @theklaas,

I am not the "guru" here, but I can imagine that a two-phase system can be possibly, as sort of 2/3 of a 3-phase system. So the answer to Q1 might be "YES" but here you need an answer from a Victron specialist for this.

For Q2 - the answer is simple and, YES the DC Source is the same for all 3-phase installations. Each Multiplus is connected directly to the same DC-Source.


For Q3 - I am sorry. I don't have an knowlegde for this.


DayAndNight

0 Likes 0 ·
theklaas avatar image theklaas dayandnight commented ·

Hello DayAndNight,


thanks for answering my questions. and hopefuly a victron specialist could take a look t my question.


0 Likes 0 ·
evgin78 avatar image evgin78 theklaas commented ·
Hi, Have you got the question answered by Victron specialist?

I've just purchased second Multiplus II inverter to install it on second phase in Australia (not split phase, 3 phase or parallel). And it appears I can't run it like this unless I add another servo GX Cerbo.

Any info would be great! I'll raise another question separately as well

Thank you

0 Likes 0 ·
shaneyake avatar image shaneyake evgin78 commented ·

Victron allows for dual phase operation. You don't need another Cerbo.
Just VE.Bus system configurator to set the correct system mode. In your case it will be Dual phase 120 or Dual phase 240, depending on which 2 phases you are using. Split phase is Dual phase 180.

0 Likes 0 ·
1 Answer
Mike Dorsett avatar image
Mike Dorsett answered ·

You have four options for adding the second inverter:

1) Totally independent on the AC Side, inverters can use the same battery, but aren't connected on the VE-Bus. CONS: Data monitoring also requires duplication, AC Side needs 415V insulation standards.

2) Connected a "parallel" pair - Not recommended if the AC outputs are not connected (not sure why you wouldn't do this) as inverters will try to share the power. Ac outputs are in sync and normal 240V isolation standards are required.

3) Connected as Bi-phase power - AC outputs are out of phase (180 shift) 720V isolation standards are required.

4) 2 units in part of a three phase system, 415V insulation standards are required.

In 2 - 4 above, the inverters need to be the same type and firmware. Also, if you want to turn one inverter off at any time, the other will also go into error mode - due to the missing inverter in the set.

My personal recommendation would be to run them as a parallel pair - I've been doing this for a few years with no trouble.

As a parallel pair, the inverters MUST share the same battery.

As for the 1:1 rule this does apply to the AC side - for the DC chargers in addition to the AC charging, you are only limited by the maximum charge current for the battery - usually only an issue with lithium batteries. Reason for the 1:1 rule is that the inverter must be able to handle the total power from the grid connect inverter, if the AC load drops to zero.


2 |3000
Toggle Comment visibility. Current Visibility: Viewable by all users

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.