Grid Tie Victron ESS with DIY LiFePO4 Battery in Australia - Regulatory Issues?

[Snapperhead]

The intent was to have all the AC wiring done by an electrician and get a COES for that part because the AC is the most dangerous.

So from this:
View attachment 162631

To this:
View attachment 162634

The main panel was completely rebuilt & a new sub-panel was installed (see pictures below).

View attachment 162632View attachment 162633

So, until batteries arrive and are installed (by me), the Victron Multi's are operating in pass-thru mode.

Given the delays & problems with getting an electrician to actually do the work, it made more sense (to me at least) to order batteries after successful AC install and COES issued.

Electrician has even offered to come back after battery install to ensure correct labeling and wiring. But because any battery install is Prescribed Electrical Work, a COES can probably not be issued for the battery components.

Including the COES, the work cost AU$3300 which was for 2 electricians for 1.5 days including parts (CB's, Distribution Board, Contactor, Wiring) but excluding Victron equipment & the Grid Protection Relay.

If you are planning a Victron install make sure the electrician verifies cable sizes & wiring with you before and as they install as this one undersized the AC Out 2 cable & CB's because he assumed the label on side of Multi was the current limit - but that value does not take account of any Grid Assist Passthru.

Great setup…. With that setup in the diagram. What occurs when there is a grid fail ? Does the fronius continue to invert etc ? Do your loads continue to be powered ? How will the battery’s change this in a grid fail (i.e. will fronius still charge them and share loads) and did you need to use any ESS setup ? If so what codes were best ? …. Sorry for multiple Barrell qns, but my new setup is almost identical here in Central Victoria Australia and I’m trying to get my head around it all ??????

 

[BipedalPrimate]

What occurs when there is a grid fail ? Does the fronius continue to invert etc ? Do your loads continue to be powered ? How will the battery’s change this in a grid fail (i.e. will fronius still charge them and share loads) and did you need to use any ESS setup ? If so what codes were best ?

When grid fails, batteries will supply loads because loads are on AC Out of Multis.

Because it is on AC In side of Multis, Fronius will get its grid forming signal from the grid and will not generate any power during grid fail.

I had originally planned, and may do later, to have the Fronius on AC Out 1 of the Multis allowing it to generate power during grid failure but that would mean allowing the Multis to feed back surplus power to the grid. Given Multis do not seem to have CEC approval to feed back to grid, it feels prudent to design accordingly.

ESS will be used.

 

[dimsum2]

there is a post on the vic community forum that says the CEC approval is about 4weeks off. So Mid Sept23 we should be good to go....well in a couple months anyway.

Hey Ghosty, any word on how this went? I'm keen to setup the below ESS but with the ability to feed back into the grid... also understand I need the Tele Grid Protection device...

 

[slash5k1]

Installed & even have a Certificate of Electrical Safety so it is all legal.

Batteries are on their way from China - EVE LF280K.

Awesome setup and I was keen to replicate until l I found out the problems listed in the forum.

Could you share with us which Grid Protection Relay you went with please and the cost?

Thank you

edit: zoomed into your install photo and I can see TELE NA003

 

[davidpb153]

When grid fails, batteries will supply loads because loads are on AC Out of Multis.

Because it is on AC In side of Multis, Fronius will get its grid forming signal from the grid and will not generate any power during grid fail.

I had originally planned, and may do later, to have the Fronius on AC Out 1 of the Multis allowing it to generate power during grid failure but that would mean allowing the Multis to feed back surplus power to the grid. Given Multis do not seem to have CEC approval to feed back to grid, it feels prudent to design accordingly.

ESS will be used.

Hi @BipedalPrimate. Going back a bit. Hope you still come back to answer this.

It's so cool that you got this working.

One thing that I don't quite get from your diagram and description is the point of the grid protection relay.

My understanding (likely wrong):

1. Configuration (simplify - assume no solar), where Multi can feedback to grid (dependent on Software Settings):
   • Grid -> main Switch -> AC in of Multi -> Ac out of Multi -> Loads
   
   
2. Configuration (simplify - assume no solar) where Multi cannot feedback to grid due to the grid protection relay (regardless of Software settings)
   • Grid -> main Switch -> Grid Protection Relay -> AC in of Multi -> Ac out of Multi -> Loads
     
3. Configuration where Solar can feedback to grid (solar or grid can charge Multi), but Multi cannot due to grid protection relay (regardless of Software settings):
   • Grid -> main Switch -> Fronius -> Grid Protection Relay -> AC in of Multi -> Ac out of Multi -> Loads
     
4. What you've drawn is:
   • Grid -> main Switch -> Grid Protection Relay -> Fronius -> AC in of Multi -> Ac out of Multi -> Loads

With what you've drawn, I can't see how Fronius can feedback to grid if the grid protection relay is setup to prevent feedback, or if the grid protection relay is setup to allow the Fronius to feedback to the grid and let you collect some FiT with excess Solar, what is stopping the Multi from feeding back? (This setup could however guarantee that there is no feedback from either the Fronius or the Multi in the case of a grid outage)

Isn't it software settings that determine if the multi can feedback to the grid? If simply connecting the grid to the AC in of the multi is enough to prevent feedback to the grid, why is a grid protection relay necessary? Or is it only in the case of a grid outage that there is an issue with feedback?

 

[BipedalPrimate]

I can't see how Fronius can feedback to grid if the grid protection relay is setup to prevent feedback

The Grid Protection Relay does not prevent feedback to grid - it only ensures that the Voltage & frequency in either direction meets the requirements of the configured grid code standard.

If any of voltage or frequency falls outside of the parameters, the grid is disconnected until they come within the parameters.


So the Grid Protection Relay provides a layer of protection in addition to that the Victron & Fronius inverters provide.

This is required because the Victron inverters have not been certified to AS/NZS 4777.2:2020.

With this design, the Victron inverters COULD feedback to grid because the Grid Protection Relay ensures grid quality voltage/frequency but I have chosen not to at this stage.

 

[davidpb153]

The Grid Protection Relay does not prevent feedback to grid - it only ensures that the Voltage & frequency in either direction meets the requirements of the configured grid code standard.

If any of voltage or frequency falls outside of the parameters, the grid is disconnected until they come within the parameters.

So the Grid Protection Relay provides a layer of protection in addition to that the Victron & Fronius inverters provide.

This is required because the Victron inverters have not been certified to AS/NZS 4777.2:2020.

With this design, the Victron inverters COULD feedback to grid because the Grid Protection Relay ensures grid quality voltage/frequency but I have chosen not to at this stage.

Thanks for clarifying, that's what I understood. I was wondering if there was an issue in that you technically can still feedback using the inverters even though they aren't CEC certified.

It would be nice to be able to choose to feedback to the grid with this setup (and more batteries); with Amber/Home Assistant, could probably start getting a better ROI on the batteries.

Really appreciate the design. Next time getting switchboard work when extending the house, I'll try to get something similar at the same time.

 

[Snapperhead]

Am I correct in assuming that Victron now had CEC approval in Australia for the MP II grid code A/477.2:2020 with new Appendix M approval ???
I assume this due to the details within the changelog of the MP Firmware 510 that states >>>
**Enabled the appendix M. gridcodes of AS/NZS4777 for standard Multis/Quattros.
(installation requires external IP)**

 

[Animalector]

Am I correct in assuming that Victron now had CEC approval in Australia for the MP II grid code A/477.2:2020 with new Appendix M approval ???
I assume this due to the details within the changelog of the MP Firmware 510 that states >>>
**Enabled the appendix M. gridcodes of AS/NZS4777 for standard Multis/Quattros.
(installation requires external IP)**

Nothing on CEC website yet, but this would be good, I am looking to go with a Multiplus, but legal connection is a problem in Australia.

 

[MondoTV]

One thing that confused me about this whole scenario was why wouldn't Victron seek certification as multimode inverters? I don't think it was a marketing decision because the way it stands, even in a mobile situation you could not connect the Multiplus II 48's to shore power. Now I know the majority of those systems are 12 or 24V which don't appear on the CEC list at all. Does "grid connected" only count if they are permanently connected?

 

[wattmatters]

Does "grid connected" only count if they are permanently connected?

I'd have thought that would apply to generation source which has the potential to energise the grid.

 

[MondoTV]

I'd have thought that would apply to generation source which has the potential to energise the grid.

Might be misunderstanding - you are allowed to connect the Multiplus II 48V's to a generation source on the input. You are not allowed to connect the input to the grid (currently). That's my understanding. That *may* be changing if that firmware note above is accurate and Victron have applied for the appropriate CEC approval. But no one should base a purchasing decision on what may happen.

 

[wattmatters]

Might be misunderstanding - you are allowed to connect the Multiplus II 48V's to a generation source on the input. You are not allowed to connect the input to the grid (currently). That's my understanding. That *may* be changing if that firmware note above is accurate and Victron have applied for the appropriate CEC approval. But no one should base a purchasing decision on what may happen.

That's a bit of a confusing description.

What do you mean by "input", input to the grid or input to the inverter? For some devices they are one and the same thing. If the connection to the grid has the potential to energise the grid, then that is the concern.

My inverter has an AC input but presents as a load only, it cannot energise the grid.

 

[MondoTV]

Referring to the AC input side of the inverter - atm it's classified as Generator input only and has the restriction of not being able to feed back to the grid.

 

[wattmatters]

Referring to the AC input side of the inverter - atm it's classified as Generator input only and has the restriction of not being able to feed back to the grid.

I think we have crossed lines. I'm not talking about what it is is/not permitted but rather what it is capable of.

Some inverter AC inputs are incapable of energising the circuit is supplying them. For them power can only flow in one direction and they can only ever present as a load. As far as the grid is concerned these are no different to a fridge or a hair dryer.

Others however have an AC input which is capable of being bidirectional. It may well be possible in the inverter's settings for it to be set not do so, however it has the capability of energising the grid.

 

[MondoTV]

I think we have crossed lines. I'm not talking about what it is is/not permitted but rather what it is capable of.

Some inverter AC inputs are incapable of energising the circuit is supplying them. For them power can only flow in one direction and they can only ever present as a load. As far as the grid is concerned these are no different to a fridge or a hair dryer.

Others however have an AC input which is capable of being bidirectional. It may well be possible in the inverter's settings for it to be set not do so, however it has the capability of energising the grid.

The Victron Inverters have a grid input which is passed through on one of the outputs (output 2) which it can still supplement with battery/generator power. If the input is disconnected the inverter goes into island mode (UPS) and only supplies the main AC output (call it essential loads). I think Victron must have had some difficulty with AS2077-2020 as they currently only have the approval mentioned in previous posts. If I had to guess I'd say it was an issue with the new frequency shift requirements being able to remotely throttle the output of the inverter when feeding back to the grid. Just a total guess. I'm not sure why that precluded them from connecting to the grid with no export - as they have an inbuilt anti-islanding relay - maybe it was just the easy path to get an approval.

 

[Bop]

The most common solution to all this is already found in many rural homes- simply having 'most' of the house set up to being on a changeover/transfer switch with 'generator input' (all rural sparkies are quite familiar with doing this, and the regs and gear to do so is commonplace, legally compliant and already fitted to many rural houses because of frequent blackouts in rural areas...)

Then simply adding a completely separate 'standalone' hybrid/offgrid inverter running off the battery bank in offgrid mode, that feeds that generator input...

By simply leaving the 'changeover switch' in the generator position, you have your house totally legally running in 'offgrid' mode, and should you need to revert to the mains power, it is as simple as 'flicking the switch'... (indeed it is possible to even have it fall back to the mains automatically by using a ATS, but effectively 'running in reverse' ie monitoring the inverters output instead of the mains grid power, and should it fail, then switch the house to the 'generator' input (which in this case would be fed from the mains grid) thus restoring power to the house from the mains grid should the offgrid inverter fail for any reason
...
Much simpler, and totally legal (and much easier to get past an inspection lol- it is just a 'power failure generator input' that happens to run 24/7 once the inspection is done...)

;-)

This also 100% guarantees no export ever (unlike some 'software' controlled systems) and is very easy to get done... (you could even if you wanted to, have a separate AS/NZ standards compliant gridtie installation on the 'mains side' of the system to offset the connection fees etc for maintaining the mains grid connection- that would just be a 'standard' gridtie setup (but would not be available for charging the battery bank)

Effectively the 'offgrid system' becomes the 'emergency generator' but happens to run 24/7...

(a lot of the compliance issues is cost related- getting certification is BIG $$$$- and unless they have the market share to justify that cost, it becomes a simple economic exercise- if it is going to take 10 years of sales to recover the cost of certification, then it simply becomes a 'yeah but nah' to the beancounters...)

 

[wattmatters]

I run like the above - with a manual transfer switch pretty much permanently left in in generator/off-grid supply position, the power for which comes from my AIO inverter.

But I do feed my AIO with grid power from a dedicated (non-backed up circuit) for pass through to loads when I want that (which is most days, as my grid PV is supplying the energy). At night it flips over to run from the battery. It has no capability to back feed the grid through the AIO's AC input - the AIO only acts as a load.

If I add a truckload more PV onto the off-grid AIO then I probably wouldn't need to pass through grid power so often. I have the extra PV there to go up but dealing with a few matters before I get round to doing that.

 

[Bop]

Although the standard 15A single phase connector commonly used on 'portable' generators has only a 3600W limit, by having a 3 phase input socket and transfer switch used instead (with all three phases joined at the inverters mains output) you are now up to 32A per phase, giving a grand total of 23kW of legal and safe offgrid supply to the house... few systems would max that out... (and again, nothing an electrician couldn't do, using commonly available- and legal- off the shelf components...)

Any electrician will happily wire a house (even a single phase one) with a 3 phase 'emergency generator input wall plug', splitting the various single phase loads across all three phases- at the inverter end its '3 phase wall outlet' is wired the same ie the single phase output of the inverter is connected to all three phase connectors in the outlet...

This is connected at the inverter output, with its single phase output wired to all three Active outputs... (you could even plug a 3 phase diesel genpack into the generator input instead lol- would work just fine...)

- plug in your 3 phase extension cord and bingo- a legal and safe up to 23kW single phase system

(less common but available are the 50A versions which would allow up to 36kW)
That's one hell of an offgrid system.....
As far as inspections go, it stops at that input socket... an electrical inspector doesn't care what happens beyond that- it is simply a 'generator input'- you just happen to be using a sun powered generator instead of a diesel or petrol powered one
;-)

 

[wattmatters]

Apologies, just realised following is not specifically about Victron and regulatory issues but is following on from the discussion on permitted wiring methods.

Although the standard 15A single phase connector commonly used on 'portable' generators has only a 3600W limit, by having a 3 phase input socket and transfer switch used instead (with all three phases joined at the inverters mains output) you are now up to 32A per phase, giving a grand total of 23kW of legal and safe offgrid supply to the house

I hadn't thought about using a 32A x 3-phase cable/plug/power inlet tied together at the AIO's output. But it's a great idea.

I have one limiting factor however which prevents me from doing that, which I'll get to later.

I have the same Hager 63A x 3-phase transfer switch as that pic above but have the three phases on the generator/off-grid supply side tied together in the transfer switch to operate as a single phase output. That was what my original sparky did some years back when we originally set it up. At the time I had a single phase petrol generator and no off-grid AIO solar/battery to use as backup (still have the generator - a Yamaha EF3000iSE).

My transfer switch on the generator input side is supplied via a single phase 32 A cable/plug/power inlet. I have an adapter cord so a 15 A generator outlet can at least supply power via the 32 A power inlet if ever that was needed. The grid side of the switch is powered by the regular 3-phase grid supply.

My 8 kW AIO's output is connected to a single phase 32 A socket/cord which plugs into the transfer switch's 32 A generator power inlet.

I confined myself to an 8 kW AIO since I was using a 32A single phase connection, but an 11 kW or 12 kW single phase AIO using a 3-phase supply cable would be much better as we occasionally sail close to exceeding the 8 kW capacity, and have tripped the AIO's overload once or twice. I'm supplying two occupied dwellings and a large outbuilding, so it's a juggling act at times. I can reasonable manage our loads but not the cottage.

My problem comes when using the system in grid pass through mode (which is roughly half the time) as I have a 32 A per phase mains supply limit.

Since my AIO's AC input is single phase, it's grid supply comes from a single phase. So even if the AIO could supply 12 kW on the output side, I cannot draw more than 32 A (~7.5 kW) for any extended period when operating in grid-pass through mode.

It sucks as my main supply fuses are 63 A but I was required by the distributor to install a 3 x 32 A mains supply circuit breaker.

Still, I sorta wish I'd got the 11 kW version of my AIO so I could ride through the occasional brief draws > 8 kW, as a breaker is not going to trip immediately. 11 kW (very rare) would take about a minute to trip a regular 32 A breaker. Most forays would be more like 8-9 kW and not last for long and a breaker is going to let that go for quite a while.

It wasn't an issue when my elderly Mum lived in the cottage, but she has since passed and it's now occupied by a young couple who tend to have higher power demands. I have some load shedding automations but even those can't help if they are not part of the load.

If my main supply breaker was 3 x 63 A then I'd go for this solution. That restriction makes it very tricky.