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Victron Advice Needed


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Good day all. Thanks to all on the forum for an excellent source of information and assistance.

I had an installation consisting of an Axpert MKS 5KVA 48V connected to 4 OmniPower 260ah batteries done 3+ years ago. The intended usage was simply to make the load shedding tolerable in the evenings by allowing us to watch television and run a few essential lights. Recently the Axpert stopped functioning and the bypass/changeover switch would not function so my only recourse was to call out an electrician and ask him to bypass the inverter and switch completely (I work away from home in Durban and there was not much else I could do). 

With the recent load shedding I decided to revisit the inverter/battery solution and bought a MultiPlus-II 48/3000/35-32. I want to take advantage of some good December pricing and procure some other bits to install when I expand the solution to include solar. So here goes my questions. 

I would like a solution like this

image.png.43d89eca595a750f1afbea672b2a40d4.png

  1. Can I purchase just one 150/35 and add more charge controllers as the installation expands or would it be better to purchase a 150/70 or 150/100 now?
  2. Is a Venus GX necessary or a good idea with an installation like this?
  3. Is the Current Sensor or Current Transformer necessary or a good idea with an installation like this?
  4. Am I right in assuming that this type of installation will reduce my electricity bill?

I am looking at JA Solar 300W Mono Percium 5BB All Black panels and would want to do the installation incrementally as funds permit. 

Thanks in advance and apologies if some of the questions or assumptions seem ill informed.

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9 minutes ago, VisN said:

Can I purchase just one 150/35 and add more charge controllers as the installation expands or would it be better to purchase a 150/70 or 150/100 now?

You can add more of them over time. The only downside is that the Venus-GX and its older CCGX brother has only two vedirect ports, if you want to add more you need to use USB cables. Not a big deal, just something to keep in mind.

10 minutes ago, VisN said:

Is a Venus GX necessary or a good idea with an installation like this?

If all you want is a UPS, then you don't need the Venus-GX. You can also do some makeshift self-consumption with just relay assistants programmed into the inverter BUT... if you want the flagship ESS solution, you must get the Venus-GX, because the control loop for that setup runs on the Venus-GX.

You can also use a Raspberry Pi to run the Venus firmware, but then you need an mk3-usb cable to communicate with the Multi. It is generally a good idea to have that cable anyway, for programming and firmware updates, so if funds is an issue you can always start without the Venus-GX and make your own.

12 minutes ago, VisN said:

Is the Current Sensor or Current Transformer necessary or a good idea with an installation like this?

Depends. The current sensor is optional. The MP-II already has one built in. The reason it is there, is so that you can connect loads on the input side of the inverter (for example your geyser and stove). These loads are not powered by the inverter when the grid goes down, but while the grid is up the MP-II can feed just enough power into the grid to compensate for those loads. In other words, it feeds power into the grid until the CT reads more or less zero. Without the CT, it feeds power in until its own input is more or less at zero.

14 minutes ago, VisN said:

Am I right in assuming that this type of installation will reduce my electricity bill?

Yes.

 

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Plonkster,

Thank you for taking the time and effort to reply, much appreciated.

It turns out that I was invoiced for a MultiPlus II but was delivered a MultiGrid 48/3000/35. Should I return it and insist on a MultiPlus II or is the difference negligible?

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Plonkster,

Wasn't the name originally MultiGrid-II and then changed to MultiPlus-II. The one that was delivered to me just says MultiGrid 48/3000/35 on the box. 

I have this one https://www.victronenergy.com/inverters-chargers/multigrid

as opposed to this one which I thought I was getting https://www.victronenergy.com/inverters-chargers/multiplus-ii

I am not sure what the differences are.

a46bbd1d-ccef-4dcf-ad39-97ada8953238.thumb.jpeg.9f80e7e3061b6092250724ba62ca546b.jpeg

Edited by VisN
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19 minutes ago, VisN said:

Wasn't the name originally MultiGrid-II and then changed to MultiPlus-II.

Ah yes, you're right. Yes, you have an older Multigrid there (I have one just like it) in the aluminium case. It's not what you ordered it seems. It is up to you whether you return it or not. This unit usually costs more than the MP-II, so on the one hand you got a bit more value for money. It has an aluinium case  instead of steel, which I actually prefer. You have a 50A transfer switch instead of 32A, and peak power of 6kva instead of 5.5. But you also have a much higher quiescent draw (25W vs 11W). See the differences here. Up to you...

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Plonkster,

Thanks for clearing that up. While I decide on what I should do, I would like to get all my other equipment needs out of the way as I would like to go the ESS route in future.

I am getting 

1.  1 X ASS030140000 Interface MK3- USB (VE.Bus to USB)
2.  1 X BPP900400100 Venus GX
3.  1 X SCC020035000 BlueSolar MPPT 150/35 (12/24/36/48V-35A)

Will I need this https://www.victronenergy.com/accessories/ac-current-sensor 

or this https://www.victronenergy.com/accessories/energy-meter 

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2 hours ago, VisN said:

1.  1 X ASS030140000 Interface MK3- USB (VE.Bus to USB)

You need this only for firmware updates. But usually you do need to update the firmware during installation, so unless you have a friend who can do this for you once off, it is good to have the dongle.

2 hours ago, VisN said:
2.  1 X BPP900400100 Venus GX 
3.  1 X SCC020035000 BlueSolar MPPT 150/35 (12/24/36/48V-35A) 

Remember to get vedirect cables to link the solar chargers to the Venus-GX.

2 hours ago, VisN said:

No.

2 hours ago, VisN said:

Maybe. Depends on where your loads are. When running ESS the Multi closes the backfeed relay so that the inverter is connected to the grid, so essentially the grid, the inverter and the loads on the output are all connected in parallel. If the grid fails, the backfeed relay is opened so that only the loads on the output remains connected to the inverter.

With everything connected like this, the Venus-GX then instructs the Multi to feed power into the grid. The amount it feeds in is always adjusted so that it cancels out all the loads that it is aware of, so that no power is used from the grid (ie you are doing self-consumption). Naturally the Multi is aware of any loads on its output, but if you have loads elsewhere in the house which might not be connected to the Multi's output (typically things like a geyser and a stove that remain connected directly to the grid, no backup), then you can install an energy meter like the above and connect it to the Venus-GX (you also need a usb-rs485 cable). Then this measurement from the energy meter replaces the internal measurement from the Multi, and it can feed back power for those loads that are directly connected to the grid.

So the energy meter is optional, but often it makes for an easy way to send power to loads without rewiring everything to move them to the output side.

Remember that the Multi also has a second output. The second output is disconnected when there is an outage. If it is possible to put your non-essential loads on AC-Out-2 of the Multi, then you also don't need the energy meter.

Finally, remember the Multi can only handle 50A (or 32A for the MP-II) through its transfer switch, which might mean that you cannot put some loads on the output. In those cases, you have no choice but to use an energy meter IF you want to compensate for such loads.

And finally-finally (I keep thinking of more things), the Multiplus-II has a an optional external current transformer (cheaper than an energy meter) that does the same thing.

Edited by plonkster
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@VisN, although both units are highly and very similarly spec'd. I would still recommend you swap it for the later model.

One the the strong points of Victron equipment the ability to parallel unit, however this requires you to have identical units.

As you never know what the future will bring I think it's prudent to leave that option open, rather than getting a unit now, whose twin will not be available in the future.

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11 minutes ago, phil.g00 said:

@VisN, although both units are highly and very similarly spec'd. I would still recommend you swap it for the later model.

 One the the strong points of Victron equipment the ability to parallel unit, however this requires you to have identical units.

As you never know what the future will bring I think it's prudent to leave that option open, rather than getting a unit now, whose twin will not be available in the future.

That is an excellent point and something I hadn't thought of. 

Thank you.

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35 minutes ago, phil.g00 said:

@VisN, although both units are highly and very similarly spec'd. I would still recommend you swap it for the later model.

One the the strong points of Victron equipment the ability to parallel unit, however this requires you to have identical units.

As you never know what the future will bring I think it's prudent to leave that option open, rather than getting a unit now, whose twin will not be available in the future.

Though something tells me that the MultiPlus II has been made to be more affordable and therefore might not be as robust as the older tech models. 

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22 minutes ago, VisN said:

might not be as robust as the older tech models

What I know about them, is that the relay used for the transfer switch component is smaller and the case is made of steel. It further benefits from the existing improvements in manufacturing of the older 3KVA Multi (the most popular model). It is essentially the same inverter on the inside.

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Hello, VisN

I have a Multiplus II 3000, a Venus GX and a bluesolar 150/60. A MK3 to USB is needed for the Multiplus II (Or Multiplus) and a Vedirect to USB for the Bluesolar (Not needed if you use a Smartsolar). Because you will have to store parameters in the multiplus, in the bluesolar and in the venus gx. The Venus gx can be accessed via wifi.

I only use them in ESS mode with a current sensor. Exactly like your picture in #1 post.

You will also need the mk3-usb in order to upgrade your Multiplus or your Multiplus II. There have been an important release in order to accept the full power 2400 W in ESS mode. Without this release the Multiplus converter will only provide 2000W and the Multiplus II only 1600W in ESS mode. When you connect your multiplus to a pc via mk3 don't forget to disconnect the Venus Gx.

Sorry for my bad english, I live in France but If I can help, I will.

:)

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2 hours ago, planetaire said:

When you connect your multiplus to a pc via mk3 don't forget to disconnect the Venus Gx. 

Not needed anymore. The mk3 will send a frame on the wire that tells blocks the other end. But when you do firmware updates it is still advisable.

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I have no idea when I will sort out my issue with the wrong inverter being delivered and I'm now a bit worried about the state of my batteries which I've measured at around 52V. I want to charge them back up to their acceptable level one by one. I therefore need a suitable charger for my OmniPower 260ah AGM+Gel VRLA batteries. I was looking at this https://nocogenius.co.za/product/g7200-noco-genius-multi-purpose-battery-charger-7-2-amp/ but was hoping someone here could advise me better. 

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  • 3 weeks later...

Strangely the box graphic doesn't match the label nor the contents. Inside the box resides a MultiGrid II with a green stripe as opposed to a MultiPlus II with the orange stripe. Am I right in assuming that there is zero difference between the MultiPlus II and MultiGrid II apart from the name and the colour of the stripe. It's also strange that there is a price difference of about R900 between the 2 if there is no difference apart from nomenclature and branding.

image.png

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2 hours ago, VisN said:

MultiPlus II and MultiGrid II

There are no Multigrid II's, only Multigid. What am I missing?

https://www.victronenergy.com/inverters-chargers

FYI: MultiPlus-II 48/3000/35-32 230V (formerly called MultiGrid-II) see here: https://www.victronenergy.com/upload/documents/MultiPlus-II-to-MultiGrid-and-MultiPlus-comparison-EN.pdf

Edited by Guest
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TTT,

All very confusing but the MultiPlus II was originally called the MultiGrid II and it seems they were packaged in boxes saying plain MultiGrid. Here is the one that was delivered to me.

image.thumb.png.f80d0e17b88dec85643e0e884441acbc.png

Here is a snippet of a pricelist listing both.

image.thumb.png.e140f01284fa9fa066972cf8416fb3a7.png

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Blow me down. I cannot find it on Google. See a lot of Multgrid II names but the pictures are the Multiplus or the Multigrid.

And nothing on Victron's site. We need @plonkster here. 

Maybe the Multiplus became the Multigrid II that then the was named Multigrid (which me and Plonkster have) to the now latest Multiplus II which is the better buy.

Me, I would send it back, get a refund as you want the latest Multiplus II and nothing else. Me, I wanted 24v so I had to take the Multigrid.

If you can do that, get a refund, and want to get a Multigrid II, the new one, drop me a PM.

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TTT,

Thanks, I think the 2 units are identical and it was just a name change. This https://www.victronenergy.com/inverters-chargers/multiplus-ii page says "Note: for a short period of time this product was called MultiGrid-II."

It causes massive confusion though, why they would change the name to MultiPlus II after starting life off as MultiGrid II is perplexing. 

 

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