Victron Multiplus tripping on startup with my old washing machine — normal?

Old washing machines are basically just motors wrapped in false hope, and motors are the arch-nemesis of every inverter ever bolted to a narrowboat wall.

Your Multiplus is seeing a massive inrush current at startup — old-school washing machine motors can pull 6–8x their running current in that first half-second, so even a beefy Multiplus II 3000 will flinch if it's not configured right.

Few things worth checking:

• PowerAssist settings — if you've got shore power or a genny in the mix, make sure it's actually kicking in rather than leaving the inverter to cope solo
• AC input current limit — too low and it'll trip rather than draw extra
• Transfer switch delay — sometimes tightening this up helps with the initial surge
• UPS mode — some folks swear by toggling this on older appliances, others say it makes no difference

Also worth poking around in VE.Configure and checking your dynamic current limiter isn't being overly precious about it.

If your washing machine is genuinely ancient, it might be running an induction motor rather than a modern inverter-driven drum — those are genuinely spiteful at startup and no amount of fiddling will fully tame them.

Honestly, I replaced a 2003 Zanussi with a newer brushless-motor machine and my Multiplus stopped having what I can only describe as an existential crisis every Monday morning.

Anyone else had luck with the weak AC setting for this sort of thing? Feels like a dark art that nobody fully understands.

@BC_Boats is right about the inrush current, but worth quantifying it properly before assuming the Multiplus is undersized.

Old direct-drive washing machine motors can pull 6-8x rated current at startup — a 2kW machine potentially demands 12-16kW for those first few cycles. Your Multiplus has a configurable AC input current limit and also a transfer switch that's notoriously sensitive during motor startup transients.

Two things I'd check first:

• PowerAssist settings in VictronConnect — if it's enabled and configured too conservatively it'll trip before the motor even gets going
• "UPS function" toggle — disabling this can sometimes reduce transfer sensitivity

On my static caravan setup I run a Multiplus-II 3000 and had similar grief with a fridge compressor until I adjusted the dynamic current limiter settings via the VE.Configure software. Not glamorous, but it sorted it.

What's your battery bank capacity and current Multiplus model?

@BC_Boats nailed it — old direct-drive washing machine motors can pull 6–8× their running current on startup, so your Multiplus is basically having a cardiac arrest every spin cycle.

Check your inverter's PowerAssist settings in VictronConnect — bumping the transfer switch sensitivity can help, but honestly the real fix is enabling the "weak AC" input setting if you're shore-powered, or fitting a soft-starter (Eco-Worthy and others do them cheaply).

Had identical grief running a shepherd's hut laundry setup — solved it dead quick with a soft-starter inline, cost about £40, Multiplus hasn't flinched since. The Multiplus 2000VA can handle most machines once that inrush spike is tamed — don't let anyone talk you into unnecessarily upgrading to the 3000VA just yet.

Had this exact drama with a 1990s Hotpoint in the shepherd's hut — "soft start" setting in VictronConnect is your first port of call before you start throwing money at a bigger inverter.

@ExFarmer79 already grabbed the soft-start glory, but if that still doesn't crack it, a dedicated motor-start capacitor wired in-line sorted my ancient van-conversion spin cycle nightmare faster than you can say "warranty void."

@CotswoldDweller's capacitor suggestion is solid but honestly if you're running a pre-millennium washing machine off a Multiplus you're basically asking a Swiss watch to punch a bear — consider just oversizing the inverter rather than fighting physics with capacitors and crossed fingers.

My Multiplus-II 3000 handles my van's compressor fridge without drama precisely because I bought more inverter than I needed — inrush headroom is your friend.

Also worth checking: what's your battery C-rate? Even a correctly sized Multiplus will trip if the cells can't deliver the instantaneous current — old AGMs are notorious for this. Fogstar Drift LiFePO4 solved that problem for me overnight, quite literally.

Short version: soft start → battery check → upsize the inverter → or just buy a modern washing machine with an inverter motor and stop torturing yourself.