If we are leaving for holidays I usually always unplug my machines but I do have my Bernina 820 plugged into a surge protector. My DH insisted on one Very expensive Surge Protector for our 50" tv & my Bernina is worth WAY more than his tv. Our house got hit by lightning about 4 years ago & blew out our phone lines but not the electricity & I had never given thought to my sewing machine until my dealer asked me if my machine was okay. Since then, surge protector it is, even though I unplug my machines if a storm is coming. Why risk ruining our machines?