Orion DC-DC Converters Non-isolated 24/12-70A fan seems to be running all the time, is that normal?

Had this exact curiosity with my Orion-Tr Smart 30A (isolated version, granted) when I first installed it in the motorhome. The fan behaviour on these Victron units can seem a bit odd until you dig into the specs.

On the non-isolated 24/12-70A specifically, that's pushing serious current — 70A at 12V output is 840W of conversion, and even at Victron's quoted ~96% efficiency you're still dissipating roughly 35W as heat internally. The fan running continuously under load is entirely expected behaviour.

The bit worth checking is whether it's running at full speed constantly versus just ticking over quietly. There's a difference:

• Gentle low-speed hum = thermal management doing its job, perfectly normal
• Full-blast rattling = possibly insufficient airflow around the unit, high ambient temperature, or it's being pushed near its limits continuously

A few things I'd investigate:

1. Mounting orientation — Victron recommend horizontal mounting for optimal airflow on these units
2. Ambient temperature — in a van or motorhome in summer it can get brutal in the habitation space
3. Actual load — are you genuinely pulling close to 70A output regularly? If so, the fan will work accordingly

Regarding your remote switch — worth knowing the remote connector on the non-isolated Orion is just a simple H-bridge enable/disable. It won't affect fan behaviour when the unit is actively converting. The fan is controlled purely by the internal thermal management, not the remote on/off state.

Would be curious what your actual load profile looks like. Anyone else running the 70A non-isolated version seeing the same thing?

@ExFirefighter42 Worth noting that the 70A non-isolated is quite a beast compared to your 30A isolated - it's shifting a fair chunk of current so the thermal management works harder. From what I've seen, the fan on the higher-amperage non-isolated units does tend to run more readily than on the smaller isolated versions.

Have a look in VictronConnect at your actual load percentage - if you're regularly pulling anywhere near full rated current, constant fan operation is entirely expected. The non-isolated units also tend to run warmer by design since they're missing the transformer that the isolated versions use.

Worth checking your installation too - if it's in a poorly ventilated locker the fan will work overtime trying to compensate. Give it a bit of breathing room and you might find it settles down considerably.

Good question for the non-isolated 70A specifically — that unit can push 840W at full tilt, so thermal management is more aggressive than on the smaller isolated versions.

From what I've read in the Victron documentation, the fan on the non-isolated 70A runs continuously once the unit is active (not just under load), whereas the smaller units tend to be more thermally reactive. It's by design rather than a fault.

Worth checking a couple of things methodically:

• Is the unit mounted with adequate airflow clearance (Victron recommend space above and below)?
• What's the ambient temperature in your install location?
• Are you seeing it in VictronConnect — does the unit show any temperature warnings?

I'm considering one of these for EV charging duties on my static, so I've been researching this fairly carefully. The continuous fan behaviour seems consistent across reports I've found online.

@GrumpySkipper @BlownFuse both on the money there. Running the 70A non-isolated on my narrowboat for about 18 months now and the fan behaviour genuinely surprised me at first.

What I've noticed is that mine spins up almost immediately once charging kicks in properly — even at modest loads. Had a chat with someone at Victron's UK distributor who explained the non-isolated units run warmer by design because there's no transformer isolating the heat path the same way.

Worth checking your VictronConnect app — you can see the unit's internal temperature in real time. If the fan's running constantly but temps look sensible (under 60°C or so), it's almost certainly just doing its job. Mine settles into a steady hum rather than cycling on and off, which is apparently perfectly normal for sustained high-current draws.

Only worry if it's running flat-out on a cool day with minimal load.

The fan on my van's Victron gear basically doubles as a white noise machine at this point — the 70A non-isolated runs warm by design, and Victron's thermal curve means the fan kicks in well before you'd expect trouble, not after. Check VictronConnect and you'll see the exact temperature threshold it's dancing around; if it's not throwing any alarms and your voltage output looks clean, the fan doing its thing is genuinely just the thing it does rather than a cry for help. Only time to panic is if it's screaming flat-out at low loads — that might suggest restricted airflow around the unit.