humming transfer switch
any advice on transfer switch humming all the time some times very loud..do they make a quite one???
Forum Discussion
Some transfer switches use AC to hold the coils. This can cause a hum because the AC power is always flowing in the coil at 60 Hz. Some better transfer switches use DC coils. This reduces hum since the coil power is DC. It does add some cost and complexity because now the switch incorporates a rectifier circuit to make the DC.
The quietest should be a switch with contacts that are mechanically held. This wouldn't involve any power flowing thru the coils except when the switch changes position. This type is commonly used in large generator transfer switches for buildings.
The quietest should be a switch with contacts that are mechanically held. This wouldn't involve any power flowing thru the coils except when the switch changes position. This type is commonly used in large generator transfer switches for buildings.
