Is 60hz buzz noise normal?

I have a new NUC 54250WYK.

I set the minimum fan speed to 18% (in BIOS), and the fan is very quiet.

However, I hear a 60hz buzz if the NUC is 40cm from my ear in a silent room.

Is it normal for the 60hz buzz to be that loud?

This buzz is coming from the case (not the power brick).

If the fan runs with minimum speed set at 40%, the buzzing sound is masked by the louder fan noise.