We are an installer from the Netherlands and recently started working with Victron. Many of our clients want their entire 3-phase home to remain powered off-grid in case of a power failure. However, they don’t want to replace their entire main AC switchboard. This presents a few challenges:
According to Dutch regulations, the entire AC switchboard must be disconnectable from all power sources with a single operation.
There is often not enough space to install both an on-grid switchboard and a separate off-grid switchboard.
With these challenges in mind, we have developed three possible solutions. My preference is for Solutions 1 and 2, allowing the client to choose based on preference or the available space in their switchboard.
Victron Setup
At the Victron inverters, we typically use the following setup (not showing switch-disconnectors):
Solution 2: 8-Pole Main Switch + Changeover Switch
This setup is similar to Solution 1 but includes a changeover switch. The changeover switch allows for manual switching in case of a Victron system failure or during maintenance.
Solution 3: Changeover Switch as the Main Grid Switch
In this approach, the changeover switch serves as the main grid switch:
Switch left → Powers Victron AC-in and closes the 4-pole relay, allowing Victron AC-Out1 to supply the house.
Switch off → Opens the relay, shutting off the entire switchboard.
Switch right → Directly powers the house from the grid, bypassing the Victron system in case of failure or maintenance (relay is still switched off).
Why not place the entire house on multiplus ac out (3ph) with the current switchboard and just place a small distributor (abb 12 unit 1 row small box) with mainswitch and fuse for multiplusses?
Maintenance is hardly ever needed, didnt need to for the last 2 years
Updating should also never been done on a running system, unless new features are needed
In the Netherlands is according regulation no need to have 1 switch to switch off all groups:
In de nen1010:2020 is er in woningen geen verplichting meer om in één beweging de installatie volledig spanningsloos te maken
So please point where you got your info.
Further be carefull using a switch to go from Victron supply to Grid supply. Reason: the “0” needs to switch at same time as L1, L2 and L3 otherwise there could be an overvoltage due to short absence of “0”.
I put a big note on my switch to first turn off all groups before switching.
Hey! Thanks for the response.
You are right that it is not per se a strict rule, more of a guideline. Please see NPR5310:2024 section 4.10.2. It is advised that a switchboard can be switched off by one switch isolator.
Indeed, the correct way of switching from off-grid to on-grid is by first switching each individual breaker → then switch the change-over → then switch on each individual breaker.
But with current installations using battery backup 2 main switches will be used due to amount of available space (my case). However, the ABB switch is a good choice.
And…Victron is also a good choice.
We have used the hager change-over switch in the past. When a switchboard is all hager we use that one, when a switchboard is all ABB we use the ABB one.
Here we can just reuse the existing main switch, and add a new main switch next to it for the off-grid side. Inside the NPR5310:2024 section 4.10.2 exception 1 it explicitly states that two main switch isolators are allowed when there are two cables supplying the switchboard.
This also adds a feature that the client can force the system into off-grid mode by just switching off the on-grid main switch isolator.
