When I first got my expensive machine my electrician told me about the serge protectors that also have a battery back-up feature. This is helpful if you happen to be embroidering but more importantly it helps protect from the damage caused by a brown out. I believe that can be as damaging as a serge. They run about $50 I think but given the price of so many machines it seems worthwhile. I've just had to replace mine after about 12 years +/-.