My DIY adventure and imported batteries, looking for help with schematics

[Hendymen]

Dear Victron’s,

I have been reading along on this forum for a long time, so at the end of 2024 I and an acquaintance decided to install a home battery with inverters ourselves.

At the end of 2024, we placed an order in Asia for 20 pieces, 9.6KwH (48Vdc) wall-mounted batteries.

These were delivered at the end of January 2025.

After this, we placed an order in the Netherlands with a Victron dealer.

9* PMP482505010 (Victron multiplus-2 5000)
1* PMP482805000 (Victron multiplus-2 8000)
4* REL200200100 (Victron EM24 Ethernet)
10* LYN060102000 (Victron Lynx Distributor M8)
4* BPP900450100 (Victron Cerbo X ESS Controller)

The fuses come through a different channel.

We eventually want to make four setups, where three of the four setups are equipped with 3* Multiplus 5000 in combination with 5* battery and a setup with 1* Multiplus 8000 in combination with 5* battery.

We have also invested in quite a few meters of 50mm2 cable, cable eyes and a crimping tool. This is to make it all as neat as possible!

Now we have made a test setup and are running, this works properly!

Time for the real work! After some toil and sweating, we laid 2 thick 4*6mm2 YMvK axis cables from the meter cupboard to the garage on one of the four setups. The Solar inverter, Victron inverters and the batteries will be installed in the garage.

Now I have arrived at the electrical installation, but I would really like to have a verification from fellow Victrons!

I would love to hear what you think of the design and where there are points for improvement!

[MikeD (Mike)]

My main concern is this RCBO:

Fitted on the AC in of the inverters is not recommended. RCBO’s should be only on the outputs / Consumer boards, the cases of the inverters should be permanently bonded to earth. You are likely to get spurious tripping of an rcbo on the inverters AC in. This should be replaced with a standard over-current protection.

[owenb79 (Owen)]

My electrician installed the MultiPlus inverter from the main switchboard using a Residual Current Device (RCD). The switchboard has a neutral-earth bond. The output from the MultiPlus goes to a small consumer unit that has its own RCD, but there is no neutral-earth bond in that unit.

If there is a power cut, the anti-islanding device disconnects from the grid, and the MultiPlus inverter creates its own neutral-earth bond for the small consumer unit, ensuring that the RCDs still function. When we lose power, I do a quick check to make sure everything is still working, and I also have a power point that displays an LED indicator when it is protected.

The run from the main switchboard is over 20m through the roof. If a rat gets in there and eats the cable, there is no fault protection. You would need to ensure the cable is properly protected if you are going to use only overcurrent protection.