USB-C vs mains powered
A product powered over USB-C runs on safety extra-low voltage, which puts it outside the Low Voltage Directive: it needs EMC testing and RoHS, and that is roughly €1,400 and three weeks. Put a mains inlet in the same box and you add LVD, EN 62368-1, creepage and clearance distances, and a test programme closer to €3,800 and six weeks.
USB-C, on everything we can. It is not only cheaper to certify — it removes the highest-consequence failure mode from a housing designed by a generator. Nothing we ship puts mains inside a plastic box that somebody configured in a browser.
| Criterion | USB-C powered | Mains powered |
|---|---|---|
| Regulatory route | EMC + RoHS | LVD + EMC + RoHS |
| Indicative test cost | ~€1,400 | ~€3,800 |
| Lead time to a declaration | 3 weeks | 6 weeks |
| Enclosure consequences | None beyond normal practice | Creepage and clearance, fire enclosure, strain relief |
| Available power | Up to 240 W with PD 3.1, in practice 60–100 W | Whatever you need |
| User experience | The cable they already own | A brick and a proprietary barrel jack |
| Field failures | Cable, replaceable by the user | Power supply, an RMA |
Where the 50 V line actually sits
The Low Voltage Directive applies from 50 V AC or 75 V DC upwards. Below that you are in SELV territory and the directive simply does not apply — not "applies more lightly", does not apply. That single threshold is the largest cost step in small consumer electronics, and it is decided by a connector choice made on day one.
What stays is the EMC Directive, and RoHS, and the general safety obligation under the GPSR. Those apply to everything, including the passive parts of your product, and they are not optional because your device is small.
When mains is still right
Anything that needs more than about 100 W continuously, anything that has to run unattended without a wall wart, and anything built into a wall or a cabinet. A ceiling luminaire on USB-C is an engineering joke.
If you do go mains, the decision cascades: a fire enclosure rating, creepage distances that set minimum wall geometry, strain relief that must survive a defined pull test, and an assembly where the mains section is physically separated. That is a housing designed around a power section, not a power section fitted into a housing — which is why our generator does not offer it.