humming transfer switch
any advice on transfer switch humming all the time some times very loud..do they make a quite one???
Forum Discussion
Iron laminations. Coated with silicon layer (not silicone). They can resonate. For years GM alternators with 7-pair rotor poles were famous for this. The hummmmmm can actually loosen lamination rivets over a long period of time. Large tramsformers used for transmission lines can sometimes be heard for a hundred feet amd they are submerged in oil. Nevertheless any increase in noise is cause for a rapidly scheduled inspection IMHO :)
