the MP2 6k5 is still fairly new, but perhaps someone has already set up a 3-phase ESS with one.
Specifically, I’d be interested to know whether the 6k5 also delivers at least 6 kW in the operating mode mentioned. That’s what I found in a certificate online, at least. That would mean 18 kW in 3-phase operation! I’m asking because in single-phase operation, the 6k5 would exceed the phase imbalance limit and could easily be derated via software by Victron to remain compliant. (Or perhaps it even will be.) But with three devices, the phase imbalance should generally remain within the limit, so there should be no need to derate the MP2.
I’m asking because I’m torn between buying three 6k5s and the 5000 model, which has been on the market for some time. I’d be willing to pay the extra if I also get more power. Whether one “needs” it or not is secondary for me. A good part of this is a hobby for me anyway—just with more practical benefits in this case.
A few weeks ago, exactly this question came up here, and IIRC the answer was that the MPII-6k5 is limited to 4.6 kW whenever the German grid code is selected, regardless of whether it is operating in single-phase or three-phase mode. You should be able to find the post easily.
I know the post. As far as I remember the gist of the posts, it was also just a theoretical discussion, not based on practical experience. The 6k5 is still fairly new, after all.
Even if the three-phase ESS is limited to a total of 13.4 kW, what happens when you disconnect the grid? The system will switch to backup power mode and the NA protection will be activated. At that point, the system continues operating in island mode, so it should be able to deliver more power. Or do you have to set it up as an island without a grid code straight away in order to deliver more power?
Theory is one thing, but well-founded practical experience is worth much more.
You are probably discussing the unbalance limit permitted in Germany, which manufacturers must comply with.
As I understand it, more than 4.6 kVA may be fed into or drawn from the three-phase grid, provided that the unbalance remains below 4.6 kVA.
Here are the key points regarding the 4.6 kW limit:
Unbalance regulation: In Germany, the difference in power between the phases in the three-phase grid must not exceed 4.6 kVA. This is intended to keep the low-voltage grid stable and prevent the neutral conductor from being overloaded.
Inverter sizing: If a photovoltaic system is connected on a single-phase basis (e.g. with a small inverter), that inverter may feed a maximum of 4.6 kVA into one phase.
Exceeding the limit: If more than 4.6 kW/kVA is to be fed into the grid, a three-phase inverter must be used that distributes the power evenly across all three phases.
No, we aren’t. The question is whether a three-phase system using the German grid code and three MPII-6k5 units provides a total inverter capacity of 18 kW or only 13.8 kW.
A single-phase MPII-6k5 is limited to 4.6 kW when the grid is connected, but should be able to deliver its rated output of 6 kW when operating off-grid. The question there, too, is whether it actually does so, or whether, under the German grid code, the MPII-6k5 is always limited to 4.6 kW regardless of its configuration.
The certificate states that 13.8 kVA must not be exceeded with 3 MultiPlus units.
Whether that is actually correct is another matter. Apparently, that is how Victron has implemented it.
Could it perhaps be that the grid code, which is set individually on each Multi (if I’m not mistaken), cannot distinguish between single- and three-phase operation?
That sounds logical and would certainly be a sensible approach. With the grid connected, 13.8 kW is unlikely to be exceeded very often. Random load imbalances caused by consumption on individual phases—for example, a hob ring + kettle + washing machine running at the same time (on one phase)—would be balanced out across the grid. If the grid were down, this balancing could no longer take place, and a 5000 would go into overload or shut down in this situation. The 6k5 could probably still cope.
You may well be right about the “otherwise”; I hadn’t interpreted it that way before. That would make it logically consistent again.
It would be great if someone with practical experience could confirm this. @Meine_Energiewende Jens, have you or your customer already been able to test whether the 3p 6k5 system can deliver more than 13.8 kW when operating in parallel with the grid?
I interpret the “otherwise” to mean that a three-unit setup isn’t affected by this either.
It kind of makes sense, too: at the end of the day, I can still draw power without the inverters until the SLS devices start glowing—or the service connection does…
…and ideally I’ll stay within the phase-imbalance limit while doing so, or maybe not…
Under full load, it comes in at almost exactly 19 kW. One thing you mustn’t forget with all MP2s is their 30% overload capability for 30 minutes. That can get you out of quite a few tight spots.
With four Pytes, definitely. The 48100R units are limited to 50 A maximum, so roughly 10 kW. Four batteries are too few for that. Even the V5a units can only handle 75 amps, which would still give you 15 kW.
Sorry for digging up this old thread, but I have the same problem.
I’ve had an ESS with 3× MP2 6k5 units running in Austria since last week. According to the TOR certificate, each individual unit is limited to 3.68 kW. However, it also states that this limitation does not apply to a balanced three-phase ESS. That’s how I’ve configured it.
Nevertheless, my 6k5 units only feed in a maximum of 3 × 3.68 kW, even when I set the requested value higher.
Has anyone had more experience with these now, or perhaps even in Austria?
As far as I know, the MP2 6k5 isn’t yet included in the current TOR list of power-generating facilities or the inverter list in Austria. Did your grid operator accept it anyway, or did you submit a special approval/certificate for it?
After waiting for months and with the deadline for the subsidy having expired, I called the grid operator and asked to be put through to the relevant department. I told them that I had an inverter with a different power rating which had a TOR certificate, but wasn’t on the list like the other models in the series. They said that the electrician should tick the box and that they didn’t actually need to specify the exact model.
The grid code is available for Austria, but apparently it’s limited to 3.68 kW per device, even with three devices.
I’m currently dealing with the same issue. I’m in the process of registering the system: 3x6k5 with a 30 kWh battery storage system + 2x10KW SMA Tripower units as the PV system.
I got stuck at the point in the registration form asking for the “maximum continuous discharge power”.
In theory, it can deliver 18 kW, but the Grid Code limits it to 13.62 kW despite the three-phase connection.
Does the 13.62 kW refer to the feed-in power, meaning that it could supply more for internal consumption, e.g. when the car is connected (not in island mode), or is 13.62 kW the general maximum?