question

jetstram61 avatar image
jetstram61 asked

AC in, MultiPlus 2 ESS

Hi,

We are looking to install an ESS with a Multiplus 2 48/3000.

We already have a 4KW grid tied solar array, so reading the ESS manual it looks like a parallel AC grid tied option is best for us.

We have an electrical engineer coming to look at our existing set up and install the ness components and wiring.

When operating in ESS mode I believe the only AC connection to the MultiPlus required is the AC IN (parallel AC grid tied). I assume therefore that the Multi uses this AC to charge the batteries with XS solar, and then in inverting mode it uses the same AC connection to push power back to the consumer units attempting to balance the loads and not draw from the grid ?

If this is correct and if we also wanted to provide head space for an second Multiplus in the future would a 32Amp supply (with the ness isolators / fuses) be suitable for AC in ?

I have a basic understanding of the system but would like a bit more knowledge so I can understand the options when chat with the engineer.

Thanks for reading this

ESS
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.

2 Answers
Jason - UK avatar image
Jason - UK answered ·

If you are using the Multiplus with AC in only connections for ESS, you will need either a ET112 meter on your incoming supply, or a Victron 100A current sensor. I recommend the 100A current sensor as its more reactive, cheaper to buy and easier to fit onto you meter tails. The only downside to your set up will be if you lose power to your property, you will not be able to use battery backup to power the property, but it does give a very simple way to provide a ESS to an existing system. In short, what you are proposing is the same as most other ESS out there, a single connection onthe AC side for invert and charging.

13 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.

Jason - UK avatar image Jason - UK commented ·
Are you going for a Multiplus II GX for a non GX version with the separate Cerbo GX device?
0 Likes 0 ·
jetstram61 avatar image jetstram61 Jason - UK commented ·
Thanks Jason. We were looking at a non GX model as I'm quite handy with the raspberry pi so am in process of looking in that as a GX option...

I was coming to the same conclusion ref the current sensor - the only issue being it will be about 15m away from the Multi and I'm not sure its extendable that far - maybe you know more ?

Regarding the AC connection - do you think a 32 Amp line will be fine for 2 Multi's in parallel at a later date ?

0 Likes 0 ·
Show more comments
ian-mcv avatar image
ian-mcv answered ·

Hi,

Sorry to hijack the thread but Im looking to do the same thing I think. multiplus-ii-gx-wiring.jpgThis is roughly my idea of how the wiring will go. I think I did fing something in one of the manuals somewhere saying that the AC IN connection was bi-directional but cant find it again.

Does it look ok?


multiplus-ii-gx-wiring.jpg (122.1 KiB)
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.