Humming from Progressive Industires EMS 50 amp system

Thanks for the replies. Good to know it isn't going to blow up the 5th wheel.
The hum is something that bothers my wife a lot more than me but it can be loud at times.
I will call PI sometime early next week as the unit is only about 6 months old and see what they suggest.
I like and will try the mouse pad idea this weekend to see what impact that has.
Great to have all you for resource folks. Get out and enjoy those units. Weather here in Oregon is darn near perfect!!
Thanks again for your help.