Due to the tremendous in-rush current required to start a 50 h.p. electric motor just as the contacor closes in you can actually hear the current going through the contactor (buzzing sound). You are hearing the actaul alternting of the current at 60 Hz. Very cool.
Sincerely,
Mike K.
Professional Traffic Light Collector & Restoration Specialist
That video is from Joe; it was primarily shown in the '04 Siren Contest. I must say that the video is great, great enough to have had me voting for it as my favorite video in the '04 Siren Contest! Speaking of a Siren Contest, does anybody have any saved on their systems?