Galvanic USB isolator

Most of our nodes are POE powered; but are not galvanically isolated from the LAN (power).

It is common (to prevent rust) to run POE at negative voltages; so the 'plus' is somewhat near 0 Volt/earth; and the 'minus' is 40-60Volt below earth. But laptops and other USB devices tend to be wired the other way round.

So it is essential to use a USB condom/galvenic separator when it is connected both to Ethernet and USB.

As otherwise there is a voltage delta of 48 or 2x72V between your devices and earth.