Installing a 3-phase Victron home battery: the preparations

Steps

1. 1

   Step 1: Planning the Layout and Wall Setup

   Before mounting any plates or units to the wall, I take time to measure and draw out everything on a sturdy white plate. This helps me see how much space I have left and ensures I do not place things too far apart when they can sit close together.

   Keeping the cables as short as possible reduces power loss in the wires and makes the whole system more efficient.

2. 2

   Step 2: Mounting the Backplate and Cable Ducts

   I screw the sturdy white plate firmly against the wall using strong bolts. At the top and corners, I leave screw holes to hang the heavy Victron MultiPlus units, which weigh about 30 kilograms each.

   For wiring, I use slotted wiring ducts measuring 40 by 60 millimeters. These ducts are thick enough to hold the 70 square millimeter power cables between the MultiPlus units and the busbars, and they allow me to easily route battery packs into the system.

   Warning

   The Victron MultiPlus units are very heavy at 30 kg each, so it is crucial to anchor them securely into the wall.

   What I used

   Item	Amount	Notes
   Wiring ducts	several	40x60 mm slotted cable ducts

3. 3

   Step 3: Installing the First MultiPlus Inverter

   I mount the first 5kVA MultiPlus II 48/5000 unit to the wall. I choose to screw the unit directly through the back plate into the wall for a sturdy and permanent installation, rather than using the included metal hanging bracket.

   Because the unit is so heavy, I temporarily remove the lid and machine cover to access the four screw holes on the back side. With some good help, we secure it tightly to the wall.

   Tip

   You can hang the MultiPlus using the included metal mounting bracket, but screwing it directly through the back plate provides a more permanent and sturdy installation.

   What I used

   Item	Amount	Notes
   Victron MultiPlus II 48/5000	1	5kVA inverter/charger

4. 4

   Step 4: Mounting the Cerbo GX Controller

   Next, I mount the Cerbo GX unit on the right side underneath the MultiPlus. The Cerbo acts as the brain of the entire battery system.

   Placing it here gives me room on the left for the busbars and easy connections to all the MultiPlus units, while keeping space clear for battery and display connections.

   What I used

   Item	Amount	Notes
   Victron Cerbo GX	1	System brain and controller

5. 5

   Step 5: Routing Main Power Cables from the Meter Cupboard

   I remove the old cable duct that was used only for lighting and a single wall socket in the shed, as I no longer need it. In its place, I install a thicker cable duct to run two 5-wire cables of 6 square millimeters from the meter cupboard to the storage room.

   The main power goes from the main switch in the meter cupboard, through the new cable trunking to the storage room, and back to the group box where I added three separate groups for the solar strings.

   What I used

   Item	Amount	Notes
   5-wire power cable	2	6 square millimeter cable

6. 6

   Step 6: Takeaways

   • Mount the backplate securely to support heavy 30 kg MultiPlus units.

   • Use slotted wiring ducts to easily route thick 70 square millimeter cables without drilling.

   • Screw the MultiPlus directly through the back plate into the wall for a permanent, sturdy hold.

   • Place the Cerbo GX brain where it has easy access to both inverter connections and busbars.

   • Upgrade old lighting cable ducts to thicker trunking to safely fit heavier 5-core power cables.