Multiplus ii 5000va Configuration Options

[BjoernK (Björn Kellermann)]

@robovanbasten

If you haven’t bought anything yet, I recommend:

Buy a MP2 10K to extend later easily.

Do not buy Pylontech as they have 15 cells instead of 16 resulting in lower voltage and higher currents. Look for Pytes or directly Gobel Power GP-SR1-xxxx (15kW batteries).

Install the MP2 parallel to your Growatt.

As you plan new switch boards, plan a manual transfer switch to transfer your loads and the Growatt from MP2 ACout1 to ACin. If you add batteries later, you can transfer all loads to the “UPS”-port ACout1. Further more, you can transfer the loads to grid later, when doing maintenance of the MP2.

You could even split (ACout1) the normal loads and Griwat vs (ACout2) the heavy leads, each with a transfer switch. I have done this on my 3-phase 3x MP2 5K system. The ACout2 can be controlled based on battery. I disconnect on SOC smaller 25%.

With the transfer switch set to grid - making the MP2 parallel (ACin) - there is no need to obey the factor 1:1 rule and you can limit batteries current while you have to few batteries.

As soon as you can afford upgrading to 20kWh battery, you can transfer all loads and Growatt to ACout1 without an electrician. You can connect low voltage batteries on your own.

The MP2 on ACin will also store you energy and serve your loads. Just the online/smart USP-feature is missing.

Pls find a picture of my 3-phase switch board.

Right: grid

Left: ACout1 critical loads with transfer switch

Middle: ACout2 normal loads with transfer switch

Left down, connection ports and breakers to MP2s.

The board is fully wired and bench tested. Loads are connected to the ports on top of each panel.

[Daza]

Doing some digging the output can’t be throttled only the charge rate from what I can see. Yes it is expensive to get it all I done mine over months every little I could and wired up as I went along the batteries where the last thing I bought then fired it up.

@BjoernK is correct with the 15cell pylons but they are so easy to come by in the UK and I think ever since Victron changed the charging profile don’t think I’ve heard high voltage alarms from anyone for a while. Not sure how the likes of the fogstar stack up. But these things are probably not what you want to hear though.

[BjoernK (Björn Kellermann)]

In Germany the 16s Pytes are cheaper. The 15kWh Gobel can be imported from CN for around 1.800 EUR including tax and shipment, all organized by Gobel. I have 5, but get only 4 into my 24 HE rack shelf…

[Daza]

@BjoernK bloodyhell man that board is a work of art but that will take up all the room in a UK house lol this is ours my double stack Hager 40way board and the main house board 20odd ways which is all now pretty populated still got high load space in the double stack board though and Hager wanted too much for there change over switch had I of had a do over I may have gone all fusebox instead as the change over switch is pretty good

[Daza]

@robovanbasten that new board where the zappi high loads are I would put a transfer switch in that so you can switch out the Multiplus all together ie the multi out goes to that and then that goes to your main CU so flick the switch and input now goes to the main board and also disconnects ac1 out, I also installed isolation switches on both ac in and ac1 out one for safe isolation fault finding and if ever you have to swap out the unit or your doing it piece by piece you house could be powered wires left in place and the AC isolator locked preventing any issues around safety.

And I don’t like how a firmware update cases the multi to have like too reboots so I just switch the house to mains isolate the multi both. Ac in and out then once done open the out and switch the change over switch then AC in.

I know what we are saying doesn’t really help where you are now but hopefully it will when if Bimble want a happy future customer

[DuivertNL (Marc)]

There is absolutly nothing wrong with pylontechs… using them without problems for years

But hey, everyone has there own opinion!

[Roamwood (Mike)]

Just a few additional comments/options:

1. where are you with the DNO G99 application, whatever you propose will have to satisfy the DNO and could significantly affect or restrict what you can do?

2. you can add a second Victron MP2 5000 in parallel with the first to increase what loads AC1out can handle, but running parallel adds complication so I would recommend going for one single MP2 10000 (or even 15000) as that can push out nearly 60amps when the grid goes down

3. if you are going to put any additional inverters on AC1out they must be of a type that Victron can control and shut down by shifting the grid frequency (when off grid if the Victron battery gets full)

4. if the Growatt cannot be controlled by the Victron then you should only put them on the ACin side of the Victron, but this means you will lose any benefit of solar/battery support from the Growatts in the event of grid loss.

5. I think you have bought already but something like the 32kWh Fogstar battery at around £3500 is amazing value and has 16 cells (or perhaps 32 cells) rather than just 15, and because the individual cells are so much larger they will have much longer cycle life. I have 3 x 14.4kWh Gobel Power batteries (so about 44kWh total) but the newer Gobel units are 16.1kWh like the smaller Fogstars (and likely use the same cells and BMS’s)

6. Like you I bought my MP2’s before I had a scheme properly worked out (and had then for 18months before I got them installed). With hindsight a single larger MP2 rather than 3 smaller ones in parallel would have been so much simpler.

7. Can you do away with the Growatt, or is it linked to a FIT scheme? your life would be so much simpler with just one (much larger) MP2. I think you could nest your Growatt and Victrons so that both are grid connected, but you will find that one will be doing most of the work, and you will likely get unpredictable feedback between them meaning that both could end up ramping power up and down to satisfy a load but at different speeds causing the other to ramp down to compensate.

8. Make your Zappi the first load after your smart meter to prevent the Zappi constantly draining your batteries. Its power take off point should be closer to your meter than any of your inverter CT clamps.

[robovanbasten (Chris)]

Hi @Roamwood , some good comments there.

1. I have 6kw export DNO G99 in place for my Growatt 6kw. I was either going to limit the MP2 to never export more than 6kw, or apply to get my G99 revised to allow more export.
2. My current plan is to get the 8000VA or 10000VA MP2.
3. I’ve checked the type test register ( ENA Type Test Register ), and the Growatt SPH6000 is listed as being compliant with frequency shifting. What I’m not sure is how frequency shifting is set? Is that a physical wired connection or a setting in the MP2? VEConfigure?

4. Should be ok based on point3.
5. Yeah mostly purchased already.
6. 8000VA or 10000VA MP2 as per point2.
7. No FIT but I spent 11k on my system so not looking to rip it up too much.
8. Can you explain a bit more about this, maybe a simple diagram? I currently stop the Zappi draining my batteries by using home assistant. i.e. If car charging set batteries to charge as well.

[Daza]

@robovanbasten Frequency shifting is done in the ESS. For it not to drain it needs to be at the Henley block and the CT’s moved to the part of the Henley that goes to the CU

Oh what did Bimble say?

[Roamwood (Mike)]

This single line diagram roughly shows my final configuration, with my Zappi physically wired beyond the ET112 meter that governs my victron system. The CT clamp for my Eddi and Zappi sits on the tails between the supplier Isolator and the Henley block that supplies the Zappi DB. That CT is actually connected to a Harvi….which brings me to another limitation you may not be aware of, as I wasnt. Using a Harvi to measure the incoming supply limits your maximum current draw from the grid to 62amps. My Victrons are capable of sinking 50amps into my batteries alone, and when doing so all my house loads are also being supplied by the grid, making my total draw from the grid close to 62 amps even without charging my car. Consequently I cannot charge my car from the grid before my house batteries are full. The solution to this problem is to hard wire the MyEnergi Grid measuring CT clamp to the Zappi, which would then allow the total grid draw to be 100amps instead of 62amps. I haven’t done this yet, so if I need to charge my car at the same time as charging my house batteries I have to use a separate car charger that I can connect to a 32amp commando socket. As the commando socket is connected to the Garage DB this charger is visible to the Victron inverters, but doesn’t drain the batteries if they are also charging. Using home assistant is a suitable solution to the battery drain issue, if I wasn’t on Octopus Intelligent Go…sometimes my car charges for just a couple of minutes in a half hour slot, so by having the Zappi outside of the Victrons, it just works. If I find I need to charge my house batteries any time that the Zappi Charges to get more benefit from off peak slots that the Zappi may generate I can do that with Shelly devices or Home assistant, but so far my 44kWh system seems adequate for my needs. With all the recent sun and limited ASHP use I have just been charging to 60% overnight to give space for solar generation the next day, As winter draws in I will increase the nightly charge to 100%, but right now having that headroom also means I can also take advantage of any Octopus free energy hours that come along which allow me to put over 11kWh into my battery bank (25% capacity)

[robovanbasten (Chris)]

@Daza

Oh what did Bimble say?

@Daza, Bimble kindly accepted the return, and I have now purchased the MP2 8000VA model, separate Cerbo GX and a Lynx Distributor. I just need to buy another US5000 and hopefully I have all the stuff needed to think about getting it installed.

[robovanbasten (Chris)]

Hi @Roamwood , thanks for the detailed response. I’m slowly pulling together the physical kit and knowledge ready for installation. Good to know about the Harvi 62amp limit, I wasn’t aware. Luckily my Zappi is positioned such it’ll be relativity straight forward to wire the CT directly, and thus achieve the 100amp.

Ref ‘Frequency shifting’, @Daza says that’s done in the ESS, by that I assume you mean the MP2? What specifically do I need to do in order to get FS enabled and working?

[Daza]

@robovanbasten Hi mate that’s great news and ultimately this is the better route with a bigger unit I’m eager to see how you get on, but plan your space take into account you may want to utilise more of the multiplus’s charge current so may commission another bank at some point. But as for the ESS as long as it’s configured in ESS it’s basically PV Assist that is prebuilt into ESS so if your using ESS the settings are in there but looks something like this PV Inverter Support Assistant [Victron Energy]

Advice once you setup just do a test so put the frequency right down for the start limit test then rest it back then drop the stop limit to below 50Hz if your PV refuses to come online it works. To be honest I don’t know of any chargers in the UK that are sold as approved ENA Solar inverters that don’t do this, my three Solis inverters do so hope this helps

BUT PLEASE DO NOT USE PV ASSIST IF YOU ARE RUNNING ESS AS ITS INBUILT TO ESS ALREADY IT JUST NEEDS SETTING UP.

[robovanbasten (Chris)]

@Daza

I would put a transfer switch in that

Hi @Daza , just coming back to you on a point you made regarding the transfer switch. Are you referring to a switch like this one, that sits in the consumer unit? I guess I would need the 100amp unit? Would need 1 or 2 pole switch? https://www.ebay.co.uk/itm/394878077339

[Daza]

@robovanbasten so it’s

So I’ve put this and additional isolators on the multiplus ie I have lockable ac rotary isolators on the input and output of the multiplus so I can isolate from the board or house and risk no gen power going to the CU just makes it easier for safe isolation knowing no one else has the lock key to switch on the isolator if I’m testing else where in the system house. Does that help?

PS there is a copper bar at the bottom which joins both input and gen input to the output but it’s like a not gate gen is active not main and if main is active not gen hope that helps

On another note don’t get any switching gear from there as it looks completely wrong highlighted 1 it has no neutral so are they saying combine neutral from mains and gen to load NO not suitable and the labelling of what im calling 2 is wrong so 2 & 4 look like they are on the same load side and the same for 6 & 8 meaning in the on position 2 and 6 are connected which going by the colours are both neutral in the off position 4 and 8 are connected which are both live so if something as fundamental as a diagram proves hard this is not where your switch gear should come from or manufacturer

[BjoernK (Björn Kellermann)]

I used this 63A 3p from Kraus Naimer.

At “big A” you can see a switching diagram for N and the poles.

Kraus & Naimer KA63B T904 VE2 +F437 Switch 4-Pin 63A with Position Mains 0...

[Daza]

Our UK consumer units are a lot smaller and output on our single phase can go to 100amp so will need higher amperage switching gear I assume @robovanbasten is single phase

[robovanbasten (Chris)]

@Daza , I see the one you mean. Would that go in my new distribution panel before the MP2? Have you got a picture of yours in situ? I only bought a 10way, I seem to be out of space already.

[Daza]

@robovanbasten So mine is segregated a little bit more my transfer switch comes from the mains after powering up the lower rail that I don’t want the multi to monitor, and then I use a Hager link to link to the transfer switch mains in then the gen in from the multi out, to the rest of the house. What are you using the ET112 to cover as at that position it will monitor the EV and showers unless this is how you want it?

[robovanbasten (Chris)]

Hi @Daza , thanks for sharing that. I’m going to reach out to the experts to get some install quotes, that include installing the MP2, replacing my old plastic WYLEX consumer unit, splitting the loads into essential and non-essential and installing a transfer switch. Regarding the position of the ET112, is this all to do with whether or not the MP2 will try to supply the heavy loads (i.e. EV and showers etc?). For the EV especially, I don’t ever want the MP2 to supply that as I always charge at night on cheap rate electric. As for the showers, I class these as non-essential but I’d still like the Growatt + MP2 to try and meet their demand (or at least the first x kW before needing to use the grid), is this possible? I assume it is and for that reason would I need to move Shower 1 and Shower 2 into the non-essential consumer unit fed from MP2 AC OUT 2?