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matth76 avatar image
matth76 asked

What load capacity will I have with this solution

Morning everyone. Ive searched for an answer on this for a couple of days but not been able to find anything. Please can anyone tell me what kind of continuous KW discharge rate I can expect using a MultiPlus 2 48/5000/70-50, with my 7.6kw array, and with a 7kw PV inverter ( to handle my 2 strings) and the 5kva MultiPlus2 48/5000/70-50, along with two Pylontech-US5000 batteries (~9kwh), in a "grid parallel" setup, both when the grid is up and also what the continuous discharge rate is when theres a powercut?


During normal operation, when the loads are big and exceed the Multiplus2 capacity then I'm hoping in a grid parallel setup the mains grid will takeover to meet our surplus demand? Our peak loads in our house can reach 5 to 6kw in our house with 11kw max being reached when I did a test with all ovens, heat pump and appliances etc are going at same time, but generally 6kw would be our average peak loads for half an hour or so in evenings. My question is, when the grid is up and running, how much grid power will I be importing with our loads potentially reaching 6kw and what about our absolute max of 11kw or will my proposed solution meet most of those loads (assuming I have plenty of charge in my two batteries)? And the same question when there is a powercut?

What is the actual continuous kW discharge rate I can expect from my solution? And will I have a "power assist" ability where short peak load demands can be met and if so how much kW and for approximately how long, before the grid takes over?


Thank you for any help and info. I really appreciate it.

Matt

Multiplus-IIPylontechess discharginggrid parallel
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Jason - UK answered ·

@matth76 I have a simular set up to what you have stated above. With the equipment ihave, my average power factor is 0.9 so my Multiplus II GX 5kva 48v runs constant at about 4.4kW. We have adjusted our energy usage to reduce the peak loads to below 5kW. In the event of a power cut, its no different, I would only get at most 4.4kW continuous. The only time my PV array supplements my loads when not charging my batteries is at weekends when I am at home or in the summer. I have a 5.7kW PV array. You can have a look at my VRM portal on the below link. In the photos is a schematic of my system as well.

https://vrm.victronenergy.com/installation/171934/share/db6807bb


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matth76 answered ·

Thank you for your reply. If I got a third US5000 in the future would this raise the continuous discharge rate to even more than the 4.4kW, or is 4.4kW the maximum the Multiplus2 5000 can put out? Thanks again.

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Jason - UK avatar image Jason - UK commented ·

@matth76 Officaly the max continuous output is 4kW. Adding more batteries will not increase the output of the inverter. The product data sheets provide the information you require.

https://www.victronenergy.com/inverters-chargers/multiplus-ii

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matth76 avatar image matth76 Jason - UK commented ·

Thank you so much for your reply. I am having to get a PV inverter to handle the high voltage input of my two PV panel strings. I have a 7.6kw pv array. I am on single phase. I have been recommended a Fronius pv inverter as it integrates very well with Victron. My question is if I got a 6kw Fronius Primo PV inverter (which can handle up to 9kw PV generation input) would I lose potential energy production compared to if I got a larger 8.2kw PV inverter? I assume the PV inverter size doesn't make a difference to the ultimate discharge rate out of the Multiplus2 5000. Thank you again.

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Jason - UK avatar image Jason - UK matth76 commented ·
@matth76 yes, if you have a 7.6kW PV array but only a 6kW inverter, your max output would be 6kW as thats the inverter output. If you had a 8.2kW PV inverter, then your array max out be your maximum output - 7.6kW.

Officially you would need your PV array on the AC in side of the Multiplus as you have to stick to the rule of having your PV output no greater than the Multiplus can handle. 5kVA multi = 5kVa max PV output.

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matth76 avatar image matth76 Jason - UK commented ·

Thanks Jason. Would having two Multiplus II 48/5000s in parallel solve the problem of the factory 1.0 rule? And what would my max discharge rate be with having two Multiplus II 5000s in parallel - would it be up to 8.8kW (2*4.4) or would it be limited to the discharge rate of the PV inverter's max discharge rate, in this case 8.2kW, or would it always be 7.6kW, ie my array? Thank you again.

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