Anyone else had grief with a Victron Multiplus 2 tripping on an inductive load? Washing machine specifically

So I've finally got my off-grid setup reasonably sorted — 8kWh of BYD lithium, a 3kVA Victron Multiplus 2, and about 2.4kW of panels through a SmartSolar 150/45 MPPT. It's been mostly brilliant, but I keep getting nuisance trips whenever the washing machine (a Bosch Series 4, roughly 2200W rated) hits its spin cycle. The inverter just cuts out with an overload fault, even though the continuous rating should comfortably cover it.

I've had a poke around in VE.Config and I can see there's an overload trip delay setting, but I'm nervous about just cranking it up without understanding what I'm actually doing. The Multiplus 2 is supposed to handle brief peaks well above its rated output — I thought that was half the point of it. Currently sitting on the factory defaults for pretty much everything apart from the charge current limits.

Has anyone dealt with this specifically with inductive motor loads? I'm wondering whether it's a wiring impedance issue (I've got about 2.5m of 35mm² cable between the inverter and the battery), the BYD BMS being a bit conservative on discharge peaks, or whether the inverter itself just doesn't like this particular washing machine. Any pointers would be genuinely useful before I start randomly fiddling with settings.

RobButler | 847 posts

@AlisonHughes sounds like you've hit the classic inductive surge problem. Washing machines are notorious for it — the motor startup current can spike to 5-6x the running current for a fraction of a second, which the Multiplus interprets as a fault.

First thing I'd try is going into VEConfigure and bumping up the AC input current limit and checking your UPS function settings. More importantly, look at the dynamic current limiter option — enabling that can really help with motor loads.

Also worth checking your battery's own BMS isn't pulling the plug first. Sometimes what looks like an inverter trip is actually the BYD cutting out momentarily due to a high current draw.

What firmware version are you running? There were some improvements to surge handling in later releases.

BoatPaddy | 1,203 posts

@AlisonHughes the Multiplus 2 3kVA has a 6kVA surge rating which sounds generous until your washing machine drum decides to do its impression of a jet engine at 1400rpm spin — had exactly this on my van conversion with a Miele and nearly launched the inverter through the roof 😅

Two things that actually fixed it for me:

• VE.Configure → crank the "AC input current limit" and check your UPS function isn't fighting you
• Set PowerAssist to let the MPPT chip in during peak surge

Also worth checking your BYD BMS isn't throttling discharge amps — if it's seeing the surge as a fault it'll fold before the Multiplus even blinks. What's your DC cable run length? Undersized cabling causes more phantom trips than people realise.

Davo24 | 312 posts

Had exactly this on my boat setup — Multiplus 2 5kVA and even that occasionally grumbled at a front-loader on a fast spin cycle.

Few things worth checking:

• Go into VEConfigure and look at your AC input current limit — if it's set conservatively it can throttle the inverter's surge headroom
• Check your dynamic current limiter setting is enabled
• Battery cable resistance matters more than people think — undersized or long DC runs will drop voltage under surge and trigger the protection

Also worth seeing if the machine has an eco or low-spin mode — dropping from 1400rpm to 1200rpm made a genuine difference for me.

@RobButler is right about inductive loads being nasty but the Multiplus 2 should handle a washing machine — I'd suspect a config or wiring issue before assuming it's a hardware limitation.

VanLee | 23 posts

Running a van conversion here so no washing machine grief personally, but I did trip my Multiplus 2 (2kVA) on a cheap angle grinder during the build — same principle I imagine.

One thing nobody's mentioned: have you checked the PowerAssist settings in VEConfigure? There's a scope to tweak the AC input current limit and assistive behaviour which might give you a bit more headroom during that startup surge.

Also worth asking — what's your battery cable sizing and fuse setup like? I found a slightly undersized cable run was contributing to voltage sag on mine, which made surge trips more likely even when the inverter should have coped fine.

@BoatPaddy makes a good point about the surge rating being less heroic in practice than on paper.

NotAnElectrician48 | 847 posts

@AlisonHughes worth checking your VEConfigure settings if you haven't already — specifically the AC input current limit and the PowerAssist settings. I had similar grief with a chest freezer compressor kicking in and found that tweaking the dynamic current limiter made a noticeable difference.

Also, some washing machines are worse offenders than others for inrush current. Older direct-drive motors are brutal. If yours has an economy or reduced spin setting, trying that occasionally can help as the motor ramps up less aggressively.

One other thing — what's your battery state of charge when it trips? If the BYD pack is below around 20% the Multiplus gets a bit more precious about surge headroom in my experience. Might be worth logging it through VRM to spot a pattern.