Victron Multiplus keeps cutting out when the washing machine kicks in

Had exactly this with my Multiplus 24/3000 on the boat last summer. The washing machine motor startup surge was tripping the overload protection — even though the continuous draw was well within spec.

A few things worth checking:

Transfer switch delay — if you're on shore power some of the time, make sure the transfer is clean. Sometimes a hesitation there coincides badly with motor startup.

DC side voltage sag — this is the one most people miss. The inverter might be perfectly healthy but if your battery cables have any meaningful resistance, the inrush current causes a voltage dip that the BMS interprets as a low-voltage event and disconnects. Had this with my Fogstar cells before I replaced the 35mm² cabling with 70mm².

PowerAssist settings — if you've got shore power or a generator in the mix, check your PowerAssist threshold in VEConfigure. Sometimes it's set too conservatively and the unit cuts before it can assist properly.

What size Multiplus are you running, and is it the 12V, 24V, or 48V variant? The 12V versions are more susceptible to this because the current figures get enormous at lower voltages. A 2kW surge on 12V is 166A+ before you account for inverter efficiency.

Also worth logging with the Victron Connect app or a Cerbo GX if you have one — the event log often tells you exactly why it cut out (overload, low DC voltage, high temperature, etc.). That narrows it down instantly rather than guessing.

What does yours show in the history tab?

Classic surge problem. The Multiplus is rated for continuous load but washing machine motors can pull 3-5x their running watts on startup — your 3000VA unit might be seeing 6000W+ for that split second.

Few things worth trying:

• Check your AC output cable sizing — undersized cables cause voltage sag which makes the inverter work harder during surge
• In VictronConnect, look at the overload trip threshold — you can sometimes tweak the PowerAssist settings
• Soft-start devices exist for washing machines, reduces that inrush spike massively

Also worth checking your battery cable lengths and connections to the inverter — any resistance there and the voltage drop during surge is brutal. I had similar grief with my garden office setup before I realised my battery terminals were slightly corroded.

What battery bank are you running? 24V with how many Ah? Makes a difference to how well it handles surge.

Had this exact issue with my static caravan setup. The fix that worked for me was adjusting the UPS function in VEConfigure — there's an AC input current limit setting that can cause the unit to hesitate before the transfer, which compounds the surge problem.

Also worth checking your battery cable gauge and connections. If there's any resistance there, the voltage sags just enough during the surge to trigger protection. I was losing nearly 0.5V across poorly crimped terminals — more than it sounds when you're hitting a motor startup spike.

@QuietTrekker is right about the 3-5x surge, but the Multiplus 24/3000 should handle it if everything else is solid. What's your battery bank capacity and cable run length, @Squib82? That'd help narrow it down.

@RetiredPlumber curious what you landed on for the UPS setting — made a difference on mine too when I had similar on the tiny house build.

One thing worth trying first though: check your AC input current limit in VEConfig. If it's set too conservatively, the Multiplus starts pulling from battery to compensate and then trips when the surge hits on already-depleted cells.

Also worth looking at PowerAssist — if that's not enabled, you're relying solely on the inverter to handle that startup spike.

My 24/3000 handles a spin cycle fine now after tweaking those two settings. Didn't need to upsize anything.

Really useful thread this. Just to add — have you checked your DC side as well? On my 24V system I found the battery cables were slightly undersized, which meant voltage was sagging badly under surge loads, making the Multiplus think it was hitting its limits sooner than it actually was. Worth measuring voltage at the battery terminals and at the inverter input simultaneously when the machine kicks in — if there's more than about 0.5V difference you've got a cable or connection problem amplifying the issue. Also @RetiredPlumber's VEConfigure point is solid, but make sure you've got the latest firmware before fiddling with those settings, as some older versions had quirks with the overload response timing. Sometimes the simplest wins are proper cable sizing and torqued connections before touching software.

@Squib82 worth checking your PowerAssist settings too — if you've got shore power connected it can buffer the surge draw rather than the inverter taking the full hit alone.

Also on a 24V system those startup spikes can be brutal. My EV charger does similar when it initialises. Bumping the dynamic current limiter in VEConfigure helped me no end.

What's your battery setup? If the cells can't deliver the surge current fast enough the Multiplus will trip before it even gets chance to react properly. Fogstar 24V lithium handled it way better than my old AGMs ever did.

Good spot from @LutonNomad on PowerAssist — that's often the overlooked one.

One thing nobody's mentioned yet: check your transfer switch settings in VE.Configure. There's a "dynamic current limiter" option that helps the Multiplus handle non-linear loads like washing machine motors more gracefully during startup.

Also worth knowing — the 24/3000 has a surge rating of around 6000W for a short period, but if your battery cables have any meaningful resistance, you'll lose headroom fast. @GeorgeSmith97 was heading somewhere useful before getting cut off there.

What battery chemistry are you running? LiFePO4 with a BMS that has aggressive surge cutoff can look identical to an inverter overload issue but is actually the BMS pulling the plug first. Worth ruling out with a clamp meter on the DC side during a startup cycle.