How do transients originate?
Over 80% of voltage spikes and impulses are caused by equipment inside yours or neighboring facilities. The starting and stopping of electric motors such as those used in automated systems and manufacturing (i.e., machine tools, elevators, HVAC, etc.) can create a continuous stream of 250V to 3000V transients. DC drives, variable speed AC drives, and DC power supply switching are other sources of transients and electrical noise. Transients may occur either in repeatable fashion or as random impulses. Repeatable transients, such as commutation voltage spikes, inductive load switching, etc., are more easily observed, defined and suppressed. Random transients are more elusive. They occur at unpredictable times, at remote locations and require installation of monitoring instruments to detect their occurrence. Frequently, random transient problems arise from the power source feeding the circuit. These transients create the most concern because it is difficult to define their amplitude, dura
