Design, Risk, and Efficacy While Testing to Standards - Tradeoffs for Surge Protective Device

Nationally Recognized Test Laboratories (NRTL) provide testing and standards for verifying the safety of electrical and electronic devices, however, it is almost impossible to anticipate all the misuse situations, lifetime wear-out conditions, and possible failure modes. Safety standards try to avoid dictating how a device should be designed and instead focus on the outcomes of defined tests. This paper discusses the issue of safe failure effects of Metal Oxide Varistors (MOV) as used in Relocatable Power Taps (RPT) for Transient Voltage Surge Suppression (TVSS) and whether the end user is getting the expected transient protection and product end-of-life hazard.