BipedalPrimate
New Member
- Joined
- Mar 25, 2022
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Let us all know how it goes.
I'm still learning here so could have this all back to frontNo real progress.
Contacted a local sparky & provided all the circuit diagrams but they balked at me doing the DC side.
Another fly in the ointment is that the Victron Multis are not approved by the CEC to feed in to the grid. So will have to replan based on the Fronius PV being on the AC In of the Multis & include a Victron Energy Meter.
Next plan is to pay a Licensed Electrical Inspector for some consulting work to review the design. Hopefully that will provide some confidence to a electrician to do the work.
Ghosty - what did your 'chap' (the mate of a mate ) advise?I have a chap coming in a week who is a mate of a mate who recently closed a battery / solar business just to make sure I can do what I want.
Grakat,is the solution to put the Fronius on the AC in side and then have the Fronius sitting between the Multiplus and the grid.
Yes this is similar to what I am thinking, except for figuring out the grid protection relay. There may also be an ~40m cable run between the Fronius and the Victron gear as the house will most probably get the grid connected stuff while the 14m x 14m shed and awning gets the offgrid gear.Grakat,
Something like this?
View attachment 140376
There is some doubt whether a Grid Protection Relay would be required - but I think it would be.
Fronius Smart Meter tells Fronius Inverter to up/down regulate PV production to maximise 5kw grid feed in limit, .
Fronius inverter reports PV production to Cerbo.
Victron Energy Meter detects current flow from/to grid and (if Cerbo ESS is set up correctly) tells Multiplus to invert from battery when loads exceed PV production or charge battery if PV production exceeds loads.
Otherwise, excess PV above Multiplus invert/charge demand is fed back to grid.
Disadvantage is there will be no PV production with PV inverter on AC In when grid fails so it depends on how reliable your grid is.
Advantage is you are not constrained by the Victron 1:1 rule when PV is on AC In.
"AS/NZS 4777.2:2020 was written/developed with a new clause/Appendix for stand-alone inverters that can connect to the grid and draw power from the grid and but not export.
multiple mode inverter
inverter that operates in more than one mode, for example having grid-interactive functionality when grid voltage is present and in stand-alone mode when the grid is de-energized or disconnected
A stand-alone inverter is not a multiple mode inverter that may operate in stand-alone mode.
I agree although there has been no advice from Victron nor CEC as to what is preventing registration.both that CEC response and the entire CEC registration are off the mark.
I think the main issue is not that the inverter itself is compliant but rather that Victron have not made any application to the CEC for approval for this inverter to interact with the grid. In my opinion the CEC is a body that really should be given a new mandate as they seem to offer opinions in some areas that conflict with established standards. Their interpretation of ELV vs the standard is a case in point.New guy here (please be gentle).
I was under the impression a Multiplus II certainly "can" export (ESS mode 2 and 3) and thus very much interact with the grid.
Making it a "multiple mode inverter" under AS/NZS 4777.2:2020
Meeting CEC's "Multiple Mode Inverter - Battery Only" requires "AS/NZS 4777.2:2020" instead of "AS/NZS 4777.2:2020 APPENDIX M" (which, as you mentioned, it already has via SAA181339).
Not just that, but AS/NZS 4777.2:2020 also explicitly states:
To my ignorant eyes, both that CEC response and the entire CEC registration are off the mark.
Given those (publicly stated) requirements Multiplus II would qualify for CEC registration as "Multiple Mode Inverter - Battery Only".
Does it not have the right "flavour" of "AS/NZS 4777.2:2020" required for CEC's "Multiple Mode Inverter - Battery Only"? Or a finer point of such certification?
It seems unlikely that the wrong "type" was applied for with CEC (but I've seen stranger things).
I think you are spot on, and to this point, it will be a tall order to get any qualified electrician to sign off on the inverter knowing this (if it is not approved). Difficult - but I guess not impossible - again open to interpretation if you add 3rd party devices. The sparky doesn't want to be left stuck holding the ball. The Victron Multiplus II supports islanding mode when configured properly. The grid protection relay is advisable for a misconfigured system. Guaranteed someone would go to jail if they got the back feed bit wrong and electrocuted someone further up the line. It's probably the bit that matters the most.I think the main issue is not that the inverter itself is compliant but rather that Victron have not made any application to the CEC for approval for this inverter to interact with the grid. In my opinion the CEC is a body that really should be given a new mandate as they seem to offer opinions in some areas that conflict with established standards. Their interpretation of ELV vs the standard is a case in point.
I have given thought about the back feeding, and I do think that there is a bit of hype in regard to back feeding. For example, i have a 230V connection which comes direct from my Pole Transformer, and then the primary side of the PT is connected to an 11KV supply. I'm happy to be corrected if I am wrong in this regard, but I'm not thinking a Multiplus running at 230V would make very much 11000K on the primary side if it back fed the grid in an outage situation. The Multiplus would probably have its own significant emotional event and trip on over current as in essence I tried to power the grid from my Multiplus.I think you are spot on, and to this point, it will be a tall order to get any qualified electrician to sign off on the inverter knowing this (if it is not approved). Difficult - but I guess not impossible - again open to interpretation if you add 3rd party devices. The sparky doesn't want to be left stuck holding the ball. The Victron Multiplus II supports islanding mode when configured properly. The grid protection relay is advisable for a misconfigured system. Guaranteed someone would go to jail if they got the back feed bit wrong and electrocuted someone further up the line. It's probably the bit that matters the most.
Multiplus II has two internal relays that disconnect the grid circuit in the event of grid falling out specs for the Grid Code selected so probably not a problem.I have given thought about the back feeding, and I do think that there is a bit of hype in regard to back feeding. For example, i have a 230V connection which comes direct from my Pole Transformer, and then the primary side of the PT is connected to an 11KV supply. I'm happy to be corrected if I am wrong in this regard, but I'm not thinking a Multiplus running at 230V would make very much 11000K on the primary side if it back fed the grid in an outage situation. The Multiplus would probably have its own significant emotional event and trip on over current as in essence I tried to power the grid from my Multiplus.
As the Multiplus is not allowed to see the grid here in Australia I will most likely put a changeover relay on the grid side of the Multiplus. That will then be compliant with our codes.
From what I can tell from regulations, that would work BUT:Would a sparky be willing to add a dedicated circuit (frankly I could wire it myself if it weren't for the regulations) to a 3 or 4 appliances from a diy battery (through a separate switch box).
I'm very interested in this setup. I was wondering if you ever progressed?
Still the same issue .... is it within 'the (stupid) regulations' and even if its a 50/50, can you find someone to sign off on it and ratify it with the electrical wholesaler in your area. Getting a multiplus to work on the grid is not hard; it's all those regs.Just wondering. Take this idea to the extreme:
Add a new switch box. Have 1 circuit that is tied Solar - Grid with feedback as per a normal house setup with existing solar (what I currently have). Except that switch box only has 1 output - one plug (plus perhaps one connection to an automatic transfer switch if possible). From that plug, you can charge the multiplus.
The multiples now feeds the old switch box, which feeds the house.
(Perhaps separate charging device and inverter as you suggest)
The sparky has to do almost no wiring. It's a quick job, single day at most (install one switch box and one plug, re-route solar and grid feed through the new switch box). Maybe a sparky can find time for a shorter job. Ideally, they would be to add an automatic transfer switch, so it can choose to power home from the grid if there is a problem with the inverter.
I have managed to at least get a quote for the installation that includes inspector approving.Still the same issue .... is it within 'the (stupid) regulations' and even if its a 50/50, can you find someone to sign off on it and ratify it with the electrical wholesaler in your area. Getting a multiplus to work on the grid is not hard; it's all those regs.