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koos147 avatar image
koos147 asked

Product advice ESS

Good day,

I am looking for some advice.

The backstory,

I live in a house with a single phase 35A main fuse. when it pops, i need to wait for somebody from the power company to replace it. Asked if they could replace it with a modern breaker (automatic) (still 35A) but they said that the cable to my house isn't compatible.

Apart from that we have fluctuating power. by law everything from 207 to 257 volt is acceptable. For more sensitive devices, i use a UPS. This ups needs to step in multiple times a day. and the planning for grid improvement are 2029. so more and more grid issues will appear in the future.

I don't have solar panels, since i didn't want to contribute to the problem.

Now is my plan to install a breaker directly after the utility meter. 32A to limit the change that the 35A fuse will pop. After this a bypass switch will route to another building (yep need to replace the current cable since it can't handle the power) here a mulitplus or quatro (or another great idea) will handle everything. the primary output will route back to the bypass switch in the consumer unit. and from here everything stays the same.

Currently the 35A is enough. we heat and cook on gas so no heavy power usage.
for future usage this could become a problem.

Not related to the question itself. but to defend the extra cost of a higher capacity device.

Upgrading this gives 2 options. 3x35A cost around €600. i have no devices needing 3 phase. but can split the load over the phases.
Higher capacity is beyond my bank account (they need to dig a trench to the near by power distribution point. lay down a new cable etc)


Long story short. i need a really large ups.

It would be nice if i can use the power assist function to use a higher load.

What does the datasheet means with peak load. is it for seconds, or can it handle this for the duration of the battery?


Also the solar panels can support the system. that should be no problem. since i can limit the export, i am not contributing to the grid problems.


For extended outages (currently not so many) i have a small generator (2300 watt)

the quatro has a seperate connection for this. when not in use, is this save to touch? (the outlet will be outside, low enough for children to touch the pins for example the picture bellow)


1713536663712.png


Is it also possible to use a Multiplus, and make some sort of input selector to switch to generator input (There should also be some settings change for example zero export & limit input)


Our ground connection is a Pen earth. so we don't need another one when disconnected from the grid.


Was also thinking to seperate the charger and inverter so i alsways have a clean output. but i think this will be inefficient an increase my monthly bill to much.

Any idea's advice or thinks i forgot?

Multiplus-IIESSQuattro-II
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Alexandra avatar image Alexandra ♦ commented ·

@koos147

Draw your power flow as a picture. Then post.

Yes the input 2 will be safe if you use a quattro and the generator input plug. It disconnects its internal relay. (Shown in a block diagram in the manual.)

Your breaker (after the fuse) will need to be significantly smaller than the 35A fuse to break before the fuse blows. A fuse tends to blow right on the rating a breaker has a trip curve and can trip much later than its 35A rating. So to save the fuse, that plan will not work.

Rate your loads in the inverters nominals rating not its peak. Peak is there for mistakes and pump starts.

If you are blowing 35A fuses then you are already pulling over 8kVa of power. (35x230v) Minimum inverter I would recommend is a 10kVa for your use.

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Duivert NL avatar image
Duivert NL answered ·

its best to contact you local victron dealer for help on designing a setup!

But with a big enough multiplus 2 or multiple in parralel, solar and enough battery capacity this can work fine for you


Multiplus can assist grid and can be setup not to feed back to grid


Read this for some more info:

https://www.victronenergy.com/media/pg/Energy_Storage_System/en/index-en.html

En in het nederlands:

https://www.victronenergy.com/media/pg/Energy_Storage_System/nl/index-nl.html

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koos147 avatar image
koos147 answered ·

@Alexandra

It took some time before i had access to Visio again. (Was somewhat disappointed about the availible stencels)

The dotted blue lines are connected. and the earth is missing for simplicity (but will be connected)

The 4 Relays represent the bypass switch (and are all switching as one)

electric.png


The change that we need a generator is small. most outages are well bellow 4 hours.

If the cost will be to high, i will find another solution (for example attach a battery charger to keep the battery filled during extended outage)

As alrady told, there is a penn earth so that should be enough even during a outage.


The datasheet is a litle bit confusing.

If the max imput is 32A (32*230=7360) and the "Cont. output power at 25 °C" 2400 is the total available power while the grid is present and the battery is full.. 9760 watt? or is the total 2400 watt?

Is it correct that only the GX version has a network connection?
I want to use this to let the home automation disable stuff based on the battery capacity (when running in inverter mode)

The story with the fuse is. that thing is really old. an no one can guaranty that it still can handle the rated amps. the utility company is really bad, and can take up to a day before they replace it (with a huge bill in the end) so if i can prevent peak load in the first place. (i normally never use this amount of power, but it is technical possible to do it)



@duivert I will let someone check my design before ordering. however i want to understand it first.

Thanks for the link. didn't know there was a Dutch version :)


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Alexandra avatar image Alexandra ♦ commented ·
Yeah. Imagine the disappointment buying expensive design program and still have to build components.... (Also looking at you autocad electrical..)

The inverters can add their inverting power to the grid input if the set up is done right. So peak can be total amps incoming plus inverting (At 25°C)

Yes the GX is the only thing connected to the internet, everything else passes information to the GX.

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Duivert NL avatar image Duivert NL commented ·

Yes the gx device controls the system, either a build in gx or a separate cerbo gx

(You dont need both) and has a connection to internet (vrm)


Max input on an multiplus 2 3000 for example means: the transfer switch is capable of max 32A straight from grid

With power assist it can deliver an extra 2400VA, so max output is then 9760W

In inverter only mode the max is 2400va


in your case i would suggest to limit power in to 25A to not blow the grid fuse, so a maximum of about 8100W is possible


With a single multiplus 2 5000 you will have more power, keep in mind that you also will need more batterys, and double if 2 multiplus in parallel


With a 35A grid fuse, 32A is to high, there needs to be a step in between for selectivity, that means 25A is the max on the input side of your house

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jeroen-kuijf avatar image
jeroen-kuijf answered ·

Good afternoon,

See this link,

https://www.victronenergy.com/upload/documents/SLD-Multiplus-II-AC-PV-and-grid-backup-2019-05-2-(1).pdf

Here you can see very basic how to setup your system with a multi, the generator can be connected with a Victron Filax, OR, when using a Quattro then you can connect the generator to the second input.

In the Multi or Quattro you can set the incoming amps from the grid and/or generator to the value you want, grid 35A, you set 34A and then it will stay between 33 and 34A, AND if you want to take more power, the batteries will automatically deliver more (power assist).

In case of no grid, the batteries will continue to deliver power, AND the generator will start automatically, all in the program of the inverter, multi or quattro.

You cannot run the generator and the grid at the same time.

You see on the output a Fronius inverter with solar panels, yes, the inverter can also charge the batteries from the output and of course from the grid or generator.

The inverter can be set as and ESS (delivery to the grid) but can also be set not to deliver to the grid and only charge the batteries and also only deliver power from them instead of the grid.

It can also be set to raise the 50Hz frequency when the batteries are full and with a MY-PV heating coil in your warm water, heat the warm water with surplus solar energy.

Read this from Victron, https://www.victronenergy.com/upload/documents/Energy_Storage_System/6292-ESS_design_and_installation_manual-pdf-en.pdf its a design advise instruction.

With regards, Jeroen.

See my system, https://vrm.victronenergy.com/installation/48664 , only with a laptop, not cellphone its to see!

P.S. Je spreekt Nederlands begreep ik?

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