UK/EU Split Phase 230V/460V Multiplus II ESS Setup

[PeakShaving (Ryan @ Peak Shaving)]

Hello Victron community.

Has anyone implemented or have experience of installing a Multiplus ESS Setup in UK/EU on a 230V/460V split phase grid supply arrangement, 3 wire 2 phase, where phases are 180degree apart.

Is it possible to have an arrangement with single battery bank and a Multiplus II on each phase operating with ESS assistant.

Grid Parallel operation only G99 & G100 export limitation will be enabled. Backup or Island mode not essential.

Have a remote rural site with this type of grid supply and would like to install solar PV, wind and battery storage, however keen on a single system solution with single monitoring and management as opposed to implementing two typical single phase setups that would be standalone, so generation can be accessed from on either phase on demand.

I see in there is a configuration option for split phase 180Degrees in the VEConfigure, however questioning is this designed only for the US 115/230V? And wondering will it work with 230V Multiplus models?

Any guidance welcomed. Thank you for your help.

[MikeD (Mike)]

As far as I’m aware, the UK or the EU does NOT operate a split phase 180 degree system, there are 3 phases that are 120 degrees separated. This gives phase to neutral of 235V and phase to phase of 401V. 460V is NOT used.
If you need to implement 2 inverters as a single system, then you can either parallel them, or install them as 2 legs of a 3 phase system. The 180 option is purely intended for the US market.

[PeakShaving (Ryan @ Peak Shaving)]

Thanks Mike.

Some photos.

Its an older type system that was implemented long ago in rural parts of the UK, however still used in some places where higher power is needed where single phase is inadequate and 3-phase not available.

Getting an upgrade to 3-phase in these areas won’t happen anytime soon as the entire overhead HV transmission lines to include the 3rd wire needed for 3-phase would need placed costing £Ms, plus replacement of all the transformers etc.

Site has its own dedicated 50KVA split phase transformer off what I gather is off a 11kV HV line, with 2 live wires and shared neutral to the incomer and polyphase utility meter. 2 x 100A fuses are fitted.

Measuring across the two lives L1 and L2 with a meter typically reads about 485Vac, with each single phase to neutral being around 240V.

[Isambard]

I have exactly the same situation to address. As you say 240/480 split phase is common in rural areas, it’s combined with single phase 11kV so changing it is prohibitively expensive.

It would be good to chat further

[Isambard]

That’s incorrect Mike. We have 3 phase as you describe, but also split phase in rural areas.

[PeakShaving (Ryan @ Peak Shaving)]

Thanks for your post, and good to hear from someone else with same challenges on the split phase

Yes certianly do get in contact, would be good to chat. Kind regards Ryan

[Isambard]

I tracked you down & messaged your colleague Robert on WhatsApp. He’s passing my details on but here they are :

Richard Landen
Renewable Energy Specialist

Isambard Ltd

Mobile: +44 797 474 0854
WhatsApp: +44 797 474 0854
https://uk.linkedin.com/in/richard-landen-71932730

[StormTrooper5560]

Hello @PeakShaving and @Isambard,

Coming to you from rural Western Australia and wanted to ask the same question as we are in a similar situation, we also have 240/480v Split phase and would love to hear further from you guys if you manage to get anywhere with this.

Thanks for your time,

[PeakShaving (Ryan @ Peak Shaving)]

Hello @StormTrooper5560 interesting to hear that split phase 240/480ac exists far away from the UK too!

Yes some progress has made on this.

Have setup 2 x 230V MPIIs and configured as 180Deg, which programmed successfully and result is 460V Phase-Phase is created in island /off-grid operation which works perfectly.

Haven’t tested connecting to grid as don’t have split phase supply, and also further testing needed to see how it would work in ESS mode, grid parallel with identifying what energy meters etc to use.

However a good indication that a result can be achieved.

[kWh.Engineering (Olly)]

Did any of you gents get this to work in 180 degree 230v as a grid connected ESS? I’ve just come across the same type of connection (at least I think I have - not metered phase to phase yet, there is a posibility it could be 2 X 230V phases at 120 degrees.)

I have the same questions - can I get two multiplus units on the same battery and GX to grid syncronise and what are my energy meter options?

Thanks in advance.

[PeakShaving (Ryan @ Peak Shaving)]

Hello Olly,

I haven’t done anything further yet on this with Victron so unsure on the best metering arrangement.

I would suspect using 2 x Multiplus II inverters with CTs directly connected to each inverter separately should work in theory and be the simplest method?

100A CTs are available and it’s rare to have a split phase larger than this. Just means system needs to be kept relatively close to the grid supply location.

In terms of using separate RS485 Energy meters only way I can see it could be done would be to install 2 X separate 230V meters, either direct connect or CT Type, address them as separate modbus IDs and connect them to a device e.g. raspberry Pi that could be programmed to read the data, collate the data and broadcast the data to the GX, effectively emulating a single polyphase Grid meter, E.g a Carlo EM530 or EM540 protocol. A bit of hardware and software required.

I am looking a split phase grid connected project at present, however have decided to use another Vendor equipment as Victron isn’t best suited for it.

Hope you get a result.

Current Transformer for MultiPlus-II | Victron Energy

[MikeD (Mike)]

Ok, I sit corrected, I was not previously aware that this was done in the UK (and other places).
I don’t see why the ESS system should not work on split phase systems - these are common in the US.
On the subject of Rural wiring, I once worked on a distribution system that used a single HV wire to distribute power - 13.5kV SWER system, uses the ground as the return.

[kWh.Engineering (Olly)]

Thanks very much Ryan. May I ask which other solutions you’ve looked at that can handle 230v split phase?

[JackAspeyEnergy (Jack)]

Hi Ryan. We have a 72kVA Quattro System operating in ESS on a 230/460v supply. We have gone for a EM24 meter. All up and working just troubleshooting the grid meter not matching the utilities meter. I don’t think commercial polyphase is vector summed hence there utility meter(bill) usage is higher than we are displaying. Will report back when we’ve got to the bottom of it. Any progress with your install ?

Our split phase transformer is 100kva so 250A fuses & CT’s

Carlo Gavazzi EM24DINAV53XE1X meter is rated to 480v L-L plus tolerance

[PeakShaving (Ryan @ Peak Shaving)]

Hello Jack,

Apologies for the delay in responding. Good to hear your are working on a split phase system also.

Have you had any success with the metering?

We haven’t made any further progress yet at our end. Have a new split project due to commence very soon that involve 20kW+ Solar PV and a 9kW wind turbine that will be installed with 80kWh of battery storage on a typical 100A split phase where we will be using 2 single phase inverters. For it we are planning on using Sunsynk solution instead of Victron, due to the simplicity of wind integration and proven reliability with wind.

72kva is a big split phase system!

On the metering front I’m not sure how the Carlo Gavazzi EM24DINAV53XE1X will work? That model is only 65A Direct Connect?

If the grid supply is 250A you would need a CT model and accompanying CTs. 250/5A.

Also the EM24 is slower at responding. I only use the EM530 meter which is much more responsive and can be configured for most scenarios being CT connection. However I don’t believe it will work split phase.

On the meter voltage, they are specified as 3-phase 400V/415V meter with tolerance. I wouldn’t be comfortable installing outside the rated range on the manufacturer datasheet of 208-480V.

A split phase supply would typically be 480V nominal L-L but wouldn’t be uncommon to exceed 500V.

Ye suits normal for the Utility Grid meter to be Arithmetic method as opposed to vector, treating phases separately. Not sure if Vector DNO meter is available in the UK?

There is a setting within ESS; individual phase should be selected.

A possible reason for a difference in the utility meter and Victron/Carlo Gavazzi reading could be If the Carlo Gavazzi is expecting phases with 120Degree Angle? I’m not sure if that is the case or if it can be configured?

I do notice the manual of the EM530 shows a 2 phase 3 wire configuration but there’s not a lot of detail

If I was implementing a Split Phase Victron ESS, I wouldn’t use the Quattros, instead would consider the Multiplus II models; Which you can connect Victron CTs directly to a master on each phase and thus as they are configured for split phase 180Degrees and measure the voltage reference internally on each phase exclusively, I would like to think the power readings would be correct and this should operate correctly on charge and discharge.

Has anyone tested this?

However I gather the limiting factor on this method is a Victron 100A CT appears to be the only option?

I guess above this power 3-phase is more practical!

I’m not sure on what the solution would be for your setup. Hope you get a solution.

[JackAspeyEnergy (Jack)]

Hi Ryan,

The site is all up and working now.

The EM24 AV5 variant is external CT’s and AV2 is direct connect. I would read the voltage as 208v - 480v plus the -20% +15. The meter can be set for split phase so 180 phase angle.

The discrepancy was due to me expecting it to be Vector not arithmetic. I believe Vector sum are available and we are looking into what options are available Not sure if the split phase setup changes anything.