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Quattro and Enphase

Hi - I'm new to this site and all things ESS! Warning - Long Post - Sorry

I want to set up a UPS for our home (in NSW Australia) using a Quattro 5kva and 48v AGM battery string (240 - 300ah - haven't decided on batteries yet). We have a 3.15kw (approx) Enphase S270 PV setup already - works great.

I believe that the basic system could be set up in parallel and the PV would cut out when grid goes down, but while the grid is up excess PV would be available to charge the batteries before export.

However, I've been told by a local installer that the system could be setup AC coupled so that during a blackout the PV would still work but exporting excess (when grid is up) would be disabled - that's fine by me.

Enphase in their documents say frequency shifting is fine but not to rely on it as they can sometimes change the parameters and therefore could cause system damage. They suggest using a Voltage Controlled Relay as well. My question is - Does anyone know how and where this device would go in the system and how it works? And in Australia is the AC coupling method suggested permitted?

Cheers and thanks for any info that can be given.

ESSvictron products
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6 Answers
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Bassman answered ·

Hi Boekel, Thanks, getting somewhere now. Ok, the PV Assistant only operates when the inverter is active and using the programmable relay. However when the grid is active, does the relay still control the pv inverters?


Cheers

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No it does not, because it is only active when the grid is not available ('when AC1 not available for 10 seconds)

Please take note that I forgot to set a second programmable relay to turn of the relay again, I'l edit my post so please read it again.

Boekel avatar image
Boekel answered ·

As you want to use the system as a UPS, and are using AGM batteries (wich ar perfect for UPS systems), you don't want to use ESS, as that continuously cycles the batteries a little bit, and you need a valid grid code with ESS.

I think you only need the pv inverter assistant:
https://www.victronenergy.com/live/assistants:pv-inverter-support

And if you want extra measures to shutdown the pv inverter, you can use one of the relays coupled to this input of the pv inverter you mentioned, like this:


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Bassman answered ·

Thanks Paul B.

I don't want the system frequency too far above norm. I accept what Enphase say:- A VCR and from further research, a current limiter on the Enphase output on Quattro AC 1 - Out to switch off PV quickly when the batteries can no longer accept excess PV.

Does the Quattro have a built in current limiter so that a VCR can configured this way?

The reason(s) for exploring this are that a) I want to know what's going on, and b) in the area I live there isn't much local Victron support or too much local knowledge etc.

Cheers

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Paul B avatar image
Paul B answered ·

How you setup the hz shut off is up to you, but the quattro can ONLY control the Freq when there is NO grid

there is also another post reply by Boekel that uses a different set of Assistants so look at the as well

by @Boekel

You don't want to use ESS, read this for configuring wat you want to do:

https://www.victronenergy.com/live/assistants:ignore_ac_input_using_the_generator_assistant

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Bassman avatar image
Bassman answered ·

Paul 8 -Thanks for reply. Does this mean that to overcome any Enphase remotely changing the setting of the S270 micros put the frequency shift high enough to ensure the micros switch off anyway? Also, while the grid is on, I'll want to charge the batteries from the most available source - grid or solar. I don't intend to generally use the batteries too much, maybe for a couple of hours after sundown - quite happy using the grid!. The main use would be for UPS for a few hours of load shedding etc - expecting more grid failure in the near future.

Cheers


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Paul B avatar image
Paul B answered ·

Hi The Enphase would be connected to the AC 1 OUT on the Quattro, however you must also setup the ESS assistant as this controls the Frequancy which will have to match the Enphase unit

ie reduce PV 51Hz reduce PV to Min 53hz turn off the PV 54hz NOW be careful with the OFF frequancy as the Enphase may say higher than 54 so then I would set the ESS to 54.1

Note the Hz figures mentioned are indicative and will be different depending of inverter used

as you can use the Quattro to discharge the batteries at night and then to recharge them first during the day and then also ONLY from solar then it maybe best to by Lithium Phosphate batteries as you may end up cycling them mush more than you expect and the life time of them is exceptional.


Also its a good idea to read up on the below

https://www.victronenergy.com/live/ess:design-installation-manual

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