Comment Re:Depends on what you mean by "problems" (Score 1) 307
Yeah we had some UPS's with line filters but they only helped a bit. Ironically it was the higher quality power supplies that were the worst, at the time there were changing regulations about power factor correction and all the new-style PFC circuits were the first to explode.
I think it was a fairly unique situation, there was some weird student designed high power laser stuff on the same circuit. If you put an oscilloscope across mains, you could see visible distortion. No filter is going to do much about that.