The build step
Previous videos covered the cabling inside the shed, the schematic, and the bench testing on a temporary grid connection. This one is the permanent install: routing the three-phase Victron set into the meter cupboard so the house draws through it, with the AC-out 1 line returning to feed the existing earth-leakage breakers. End result: a working emergency-power path.
The warning Robbert leads with is the obvious one. This is high voltage in a live meter box. Don't do it if you're guessing. Find a certified installer.
Killing the system first
The shed end of the cable run gets disconnected from both directions, so nothing can be back-fed from the Victron side while he works in the cupboard. In the cupboard he kills the extra earth-leakage breaker and then the main switch. The whole house drops. He pulls a multimeter across every terminal he's about to touch to confirm there's actually no voltage. Safety first, always verify.
The new wiring path
Four wires come down from the main switch: one neutral and three phases. He removes them from the earth-leakage breakers and from the main switch. Those cables get replaced by the new feed from the Victron set.
Going outbound from the main switch:
| Direction | Path |
|---|---|
| House to shed | Main switch → extra 25 A earth-leakage breaker → 6 mm² cable → Victron AC-in |
| Shed to house | Victron AC-out 1 → 25 A breaker in shed → cable back to cupboard → existing earth-leakage breakers → groups |
So the original wiring between main switch and earth-leakage breakers gets cut. Now power leaves the main switch, runs to the shed, passes through the inverters, and comes back to feed exactly the same earth-leakage breakers. Earth was already on the common rail.
Five wires return from the shed: three phases, neutral, earth. The earth ties into the common rail (internally bonded, so the connection point doesn't matter). The grey, brown, and black phase wires go to the line terminals of the first, second, and third earth-leakage breakers respectively. The neutral connects to one breaker, and bridge bars between the three breakers carry it to the other two.
Tightening every screw
Before powering anything back up, every screw terminal gets re-torqued. On the main switch, the line side stays live, the load side has just been re-terminated and gets the extra tightening pass. Covers go back on. He keeps the front panel of the cupboard accessible so he can probe a couple of points after switch-on.
Powering up, step by step
Order matters. He starts with everything off: earth-leakage breakers down, solar disconnected, Multiplus units off. Then:
- Main switch on.
- Extra earth-leakage breaker on. Now the shed has grid voltage.
- In the shed, the second main switch in. Each Multiplus should now read grid voltage on AC-in.
He measures each phase. The three readings: 227 V, 225 V, 217 V.
- Multiplus units on. Wait for them to boot.
- Measure AC-out 1 on each unit: 222 V, 225 V, 221 V.
- Bring the return cable into play. The cable from AC-out 1 now carries voltage back into the cupboard. He measures the underside of each earth-leakage breaker: 220 V, 227 V, 223 V.
- Earth-leakage breakers on. The induction cooktop pulls a brief inrush, normal.
The whole house is now drawing through the Multiplus set.
Testing emergency power
The test is one switch. He drops the main switch in the cupboard. The grid voltage feeding AC-in disappears. The Multiplus set detects the loss, opens its internal contactors, and switches to island mode. The house keeps running. A piezo beeps in the cupboard to flag the grid loss, but lights stay on, appliances stay on.
Throws the main switch back. The Victron set re-synchronises and hands back to the grid.
What the energy log shows
Robbert pulls up the Home Wizard log afterwards. Most of the night is flat baseline consumption. Morning peaks as the house wakes up. Sunrise, the panels start exporting, around 2 kW back to the grid on a half-shaded winter day. Then a sharp drop to zero: that's when he was filming the emergency-power test and the main switch was off. The Home Wizard meter draws a diagonal line through that gap because it can't measure, but the actual export was zero, not interpolated.
Once the meter switches back on, the house pulls from the battery, not the grid. The VRM portal confirms it: 408 W in use, 16 W from the grid, the rest from the battery pack.
Where this fits
The set is now permanently in-line, but no automatic transfer switch yet. There's also no bypass breaker between grid and house, so if the Victron set fails entirely, the house goes dark until it's repaired or bypassed. The transfer switch and bypass are next.
Takeaways
- The simplest emergency-power install is series: grid → Victron → existing earth-leakage breakers. No transfer switch needed for the basic case.
- Power-up order is grid first, Multiplus units second, then return path, then breakers. Each step gets a multimeter check.
- The Victron set hands the house back to the grid the moment the grid voltage returns, no user action needed.
- The Home Wizard log lies during the test window. The VRM portal is the ground truth.
- Re-torque every screw before re-energising. Loose terminals are the dominant failure mode in a re-wired box.
