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gero-schomaker avatar image
gero-schomaker asked

Phoenix Smart 12/3000 Installation (RCD, cables, fuses)

Hi!

I wonder if somebody can help me with some questions regarding the installation of the Victron Phoenix Smart 12/3000.

First, I am not sure which type of RCD I require. Is a 2 pole, 16A & 30 mA RCD like this one appropriate?

My second question relates to the cross-section of the cables and the size of the fuses. The manual recommends 95mm² cables and 400A fuses. However, these cables are really rigid and heavy, and I wonder if 70mm² cables with 300A fuses would not also do the trick?

I would be very happy to hear about your opinions.

Cheers,
Gero

Phoenix InverterGenerator
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3 Answers
markus avatar image
markus answered ·

The question about the right RCD is not easy to answer. This depends on your local rules and regulations.

Some local rules say, you have to use a DC capable RCD (TypeB) but this type is much more expensive.

It is best to ask your Victron Installer for that, he/she should know the local rules and regulations for your region.


The second question is easy: use recommended cross sections and fuses like stated in the manual. You have to think about Peak Power capabilities of your inverter...


Best Regards,

Markus

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gero-schomaker avatar image gero-schomaker commented ·

Thanks for the reply, Markus!

I am based in Germany and am guessing that the regulations here are probably on the strict side and might require a type B RCD. To be sure, I will look for a Victron installer in my region and ask them, as you suggest.

Interestingly, I just realized I should be able to use 2 x 50mm² cables, since my Phoenix Smart 12/3000 has two plus and two minus connectors. That is not mentioned in the manual, and there seem to be other versions of this inverter with only one pole each.

I realized this when reading this post about the Multiplus 12/3000:
https://community.victronenergy.com/questions/13247/multiplus-123000120-battery-cable-fuse-size.html

If I use 2 x 50mm² cables instead of 95mm², would I still connect them to one 400A fuse, or would I use two 200A fuses?


Thank you! :)

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markus avatar image markus ♦♦ gero-schomaker commented ·

It is perfectly OK to use 2x50mm2 instead of 1x95mm2

The fuses are there to protect the cables, so it makes good sense to use 2x200A fuses to protect each cable run independently.

Markus

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gero-schomaker avatar image gero-schomaker markus ♦♦ commented ·

Thanks! That's great, since 50mm² cables are much easier to install in the setup I have. And protecting each cable with a fuse separately sounds logical, I will do that!

One last question, mainly out of curiosity:
I have three 100ah LiFepo4 batteries with a combined maximum discharge current of 300A. I am also planning to use appliances with no more than around 2200W at a time. Is the theoretical peak power of the inverter still relevant in this scenario?

Cheers,
Gero

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markus avatar image markus ♦♦ gero-schomaker commented ·

„ Is the theoretical peak power of the inverter still relevant in this scenario?“

For a correctly installed system, indeed it is.
The system should be installed to perform under its max. power without issues.

Maybe you will have some other appliances in future and might forget about, that you undersized something.

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gero-schomaker avatar image gero-schomaker markus ♦♦ commented ·

That is a good point. I might add another battery and/or use other or several appliances in the future. Thanks!

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waldemar avatar image
waldemar answered ·

Heyhey.

Also got this inverter. Was trying to fit 95mm² cables but they do not even go through the openings! Only by removing the plastic thingy was I able to fit the cable. Is this intended?
Also the DC grounding cable, which only has one bolt instead of two, does it also need to fit a 95mm² cable? Because the bolt is a bit lower than the battery terminals. This results in the cable lug being directly in the way of fitting the cable through the cable opening. So basically there is no way to fit it through the opening unless I make the whole bigger or use a smaller cable size.

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robin-wessel avatar image
robin-wessel answered ·

I noticed the same thing as I'm in the process of specifying a system. I'm wondering if the recommendation for 2X95 mm cables is a mistake. Reason why is the same power Multiplus inverters require only 2 X 50mm cables. Example Phoenix 24/5000 requires 2 X 95 mm but the Multiplus II and Quattros 24/5000 only requires 2 X 50 mm.

Why does the same power inverter require cables that are twice as large as Victron's equivalent inverter/charger versions?

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