Anyone else had grief with their Victron MultiPlus tripping on UK shore power hookups?

Been running a MultiPlus 12/3000/120 in my narrowboat for about eight months now and I keep getting nuisance trips when I plug into marina shore power. The unit throws an overload alarm almost immediately, even when I've got sod all switched on — maybe just the fridge and a phone charger. Shore power supply is a standard 16A blue CEE connector, so in theory there should be plenty of headroom.

I've had a poke around in VictronConnect and noticed the input current limit was still set at the default 16A, which I thought should be fine. Someone on the marina suggested the shore power itself might be a bit ropey — voltage dropping to around 220V at peak times — but I'm not sure if that alone would cause the inverter/charger to go into a strop. I've also wondered whether the Dynamic Current Limiter setting might be worth enabling, though I'm not entirely sure what it actually does in practice.

Has anyone dealt with similar? Worth dropping the input current limit lower to give it a bit more tolerance, or is there something else I should be checking first? Open to suggestions before I end up ringing Victron support.

CallumReid | 847 posts

@SY_Marine had almost identical grief on my boat last year. Worth checking your shore power lead and the marina's pedestal voltage first — some older marinas have quite poor regulation and you can see voltages creeping up to 253-255V, which can upset the MultiPlus's input voltage window.

Also, have a look in VictronConnect at your AC input current limit setting. If it's set too low (say 6A or under) and you've got a battery charger cycle kicking in simultaneously with something else drawing load, it'll trip almost instantly.

The other sneaky culprit is the transfer switch timing — try bumping up the "AC low disconnect" threshold slightly in VEConfigure if you have a laptop handy. Made a huge difference for me at busy marinas where the supply is a bit wobbly.

SunnyNomad | 134 posts

@SY_Marine I had something similar when I first set up my emergency backup system — not on a narrowboat but the principle was the same. Worth checking whether the marina's shore power is actually a clean 230V or if it's sagging under load. Some older marina pedestals are genuinely awful.

Have you looked at the input voltage range settings in VictronConnect? You can widen the acceptance window so the MultiPlus doesn't reject slightly low or fluctuating shore power before it even gets chance to stabilise.

Also — is your shore power lead and the pedestal connector in good nick? A dodgy connection can cause enough resistance to drop voltage noticeably under load, which then triggers the overload protection.

What does the Cerbo/CCGX show in the history logs when it trips? That data would help narrow it down significantly.

OllieRoss74 | 312 posts

Mine's not a narrowboat — it's a shepherd's hut on a remote hillside — but the MultiPlus behaviour you're describing rings very familiar bells.

What sorted it for me was digging into the shore power current limit setting in VictronConnect. Mine had defaulted to something optimistic that bore no resemblance to the actual supply quality at my hookup point. Once I throttled it back to match what the incoming feed could realistically deliver without wavering, the nuisance trips vanished almost entirely.

Also worth logging the AC input voltage during a trip using the VRM portal if you have that set up. My supply was sagging horribly under load — something a basic multimeter would never catch in the moment.

Could be your marina's supply is equally wobbly. Older marina infrastructure often is.

WonkyBuilder | 1,204 posts

@SY_Marine Worth checking your shore power input current limit in VEConfigure — it's a setting that catches a lot of people out. The MultiPlus needs to know what your shore supply can actually deliver, otherwise it'll try to draw more than the connection can handle and trip itself silly. On marina hookups you're often limited to 16A or sometimes as little as 6A depending on the pontoon. If the input limit is set too high, the unit panics almost immediately when it sees the load.

Also worth asking the marina whether their supply is a solid TN-S or if it's a bit sketchy — some older marina installations have enough impedance that the MultiPlus ground relay check throws a wobble before you've even switched anything on.

What does the Victron Connect app show in the history? The fault codes there should point you in the right direction pretty quickly.

LazySparky | 847 posts

@SY_Marine The other thing worth looking at — and I don't see anyone mention it yet — is whether the marina supply itself is a bit ropey. Some older marina pedestals have genuinely terrible voltage regulation, and if the MultiPlus sees the incoming voltage wobbling outside its acceptance window, it'll reject shore power and flip to inverter mode, which then immediately overloads on your loads. Check what voltage you're actually getting at the pedestal with a multimeter rather than assuming it's a solid 230V. Also double-check your shore power input frequency tolerance in VEConfigure — some older marina supplies drift a bit on frequency too. Victron's defaults are fairly tight. Widening the acceptance window slightly (within reason, don't go mad) often sorts these phantom trips stone dead. What does the Victron Connect app show in the history tab when it trips?