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jyweet avatar image
jyweet asked

Is it possible to use three Multiplus II GX units in a three phase configuration?

I need to build a three phase system (ESS). Can I use three of the Multiplus II GX units, or is only one GX allowed and the other two MUST be only Multiplus II units? Can I not set the one GX unit as master and the other two GX units will operate with their GX disabled?

Multiplus-II
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marekp avatar image
marekp answered ·

You probably can, but where is economical sens of doing it this way?

MP-II GX is more expensive than plain MP-II

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jyweet avatar image jyweet commented ·

Thank you for the quick confirmation.

No it is not economical, other than immediate product availability, and the client looking for a solution a.s.a.p

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marekp avatar image marekp jyweet commented ·

Product availability can be a great motivator. :)

I can relate to that.

I am finishing my 3-phase system build on 2 MultiPlus-II and 1 EasySolar-II GX.

Did not plan to buy EasySolar-II GX but MultiPlus -II GX was not available. :)

Now I am trying to find application for MPPT 250/70 that came with EasySolar.

Probably will buy more solar panels.

In your case, you will probably have to physically disconnect those not needed GXs.

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jyweet avatar image jyweet marekp commented ·

Yes, what you say agrees with this:

https://community.victronenergy.com/questions/54262/use-more-than-one-gx-device-in-a-system.html

I just disconnected two of them now, and will see how the installation goes this week.


Thanks again for the confirmation.

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marekp avatar image marekp jyweet commented ·

With having 3 GX devices in 3-phase system I see one small problem.
When identifying units, during setup, with plain MP-II you can make them blink their LEDs so you know which one you are setting up.

When I tried this with my EasySolar-II GX I did not see any reaction to that command. Since I have only one GX device, there was no problem.

So, if I did not miss something, you have no easy way to identify them when you have all 3 GX devices.

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jyweet avatar image jyweet marekp commented ·

The setup worked fine, I just switched on the multiplus gx's one at a time and recorded the number assigned to each, then I know which one is which. The three phase setup was also fairly straight forward.


The problem I have now is with the L1 unit triggering an overload alarm in the morning under low load conditions when the unit need to switch back from utility to solar/battery power. Seems the energy from solar is not quite enough to supply all the loads when the switching happens.

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There can be another cause of “overload” shutdowns during low load conditions - see part 3 here - https://www.victronenergy.com/live/ve.bus:grid-codes-and-loss-of-mains-detection

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jyweet avatar image jyweet Guy Stewart (Victron Community Manager) ♦♦ commented ·

Hi Guy, I appreciate your time for responding here, and I also have to say thanks for your three-phase training video, it helped a lot.


The overload shutdown happened twice with low load conditions, and neither time it was related to a LOM condition (mains were live and well), and I am not too excited about the idea to disable the LOM detection. The firmware on all three units are 470.

Do I log a support request or do we continue the discussion in the community? I will also need the LOM grid code related password, I will contact my dealer an see how successful I am at obtaining such password.


Your assistance is much appreciated.

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Contacting your dealer from here is definitely the way to go.

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