... certain loads,fiuorescent lights,motor speed controls,light dimmers.Over-Voltage:Long duration(milliseconds,seconds,minutes,hours or days)rise in ... connected equipment receices a surge of electricity at an over-voltage level,which can be cery damaging(see above).What causes it ... to any piece of equipment connected to the incoming line,the telphone line itsdlf may even be damaged or destroted in sevre ...