Victron Orion 30A keeps cutting out when engine gets warm — any ideas?

Had the exact same issue on my narrowboat last summer — drove me absolutely mad for weeks before I tracked it down.

First thing to check is your input voltage. When the engine warms up, alternator output can actually drop slightly on older engines, and if you're running other loads at the same time (bilge pump, navigation lights, fridge), you might be dipping below the Orion's minimum input threshold. It'll cut out as a protection measure and you'll never know unless you're watching a multimeter.

Second thing — and this caught me out — check your cable runs and connections. Heat causes resistance to increase, so a connection that's borderline fine when cold becomes a problem once everything's been running 20 minutes. I had a slightly dodgy crimp on the input side that only showed up warm. Thermal imaging on a phone attachment actually spotted it in the end.

Worth also checking:

• Ventilation around the unit itself (mine was tucked in a poorly ventilated locker)
• Whether the engine alternator has an external regulator or is stock — some older marinised engines run the alternator voltage all over the place
• Firmware on the unit if you haven't already, Victron pushed some updates that addressed cut-out behaviour

What engine are you running? And is the Orion isolated or non-isolated? That might change the diagnosis a bit. Others on here will likely have more specific ideas — there's a few narrowboaters and van lifers who've been through similar.

@RobBennett93 good shout on the input voltage, but before assuming it's the alternator I'd check your cable gauge first.

The Orion 30A can pull close to 400W on the input side — at 12V that's over 30A through whatever's feeding it. If your cabling is marginal, voltage drop under load rises as the engine bay heats up (higher resistance with temperature). What looks fine cold suddenly triggers the Orion's low-voltage cutoff when warm.

I had exactly this chasing my tail on the shepherd's hut setup before I realised the previous owner had run 6mm² where 10mm² was needed for that run length.

Also worth connecting a laptop to the Orion via VE.Direct and logging the input voltage in real-time. Victron's VictronConnect will show you exactly when it's cutting and what the input voltage was doing — takes the guesswork out entirely.

Good points from both of you, but worth checking one more thing nobody's mentioned yet: ambient temperature around the unit itself.

The Orion-Tr Smart has thermal protection and will shut down if it gets too hot — and it's a common one to miss because the timing matches perfectly with the engine warming up, making you think it's an alternator or cable issue.

Mine's in a tiny cabinet in my cabin build and I had exactly this. Moved it somewhere with better airflow, problem gone.

Check the Victron Connect app — it logs the fault reason. If you see #33 Input voltage out of range that's the alternator/cable issue the others mentioned. If you see a temperature fault code, that's your answer right there.

Don't go chasing cable gauges until you've actually read what the unit's telling you.

@PeakExplorer that ambient temp point is massive — had my Orion tucked behind the engine bay bulkhead on the van and it was throttling constantly in summer. Moved it to a ventilated spot under the bed and problem basically vanished.

Also worth checking: is your input protection threshold set correctly in VictronConnect? The Orion-Tr Smart lets you tweak the "input voltage lockout" — some people accidentally have it set too high and it trips as soon as voltage dips even slightly under load.

Had mine set wrong for months, convinced it was a wiring issue. Five minutes in the app sorted it.

Check the history tab too — it'll show you exactly how many times it's cut out and what triggered it. Victron's logging is actually decent for diagnosing this stuff.

@WezFrost mine did exactly the same until I velcroed a £4 USB fan to the bracket — the Victron Connect app showed thermals dropping 15°C and it's not cut out since, which is either genius-level engineering or a damning indictment of where I mounted it originally.