From the bloggers at RV Travel.
I have replaced the Ground Fault Interrupter in my Class A motorhome and the new one hums when the inverter is on. Do you know why? —Denise D.
My immediate thought is that the new one simply does not know the words! Or it might have something to do with an internal line balance-detecting transformer (more likely). This, of course, is assuming no modifications were made to the wiring at the inverter itself.
To read the full story by RV Travel, click here.