IEC 62368-1 and Pluggable Mains Powered Equipment Surge Protection

March 6, 2019
2:25  -  3:05 pm

Most countries are forecast to have replaced the IEC 60950-1 safety standard with IEC 62368-1 by mid-2020. Here, the USA and Canada are ahead of the pack by setting a mid-2019 date. The IEC 62368-1 mains port surge protection function of pluggable mains-powered equipment is unique in that it requires a metal-oxide varistor (MOV) to have a series gas discharge tube (GDT). The presentation explains what are the aggressive IEC 62368-1 component test requirements that the MOV and GDT must meet. The GDT must meet a high voltage insulation withstand (no sparkover) voltage (> 2 kV) together with creepage and clearance distances. The MOV or MOV and GDT combination must survive or fail without causing a hazard during a series of temporary overvoltage (TOV) stress tests. Based on the IEC 62368-1 requirements, various protection circuit design examples and component values are given.

Learning points:

  • IEC 62368-1 overview
  • Perceived MOV hazards and necessary safeguards
  • Pluggable mains-powered equipment surge protection function
    • GDT tests and parameters
    • MOV or MOV and GDT combination tests and parameters
  • Protection circuit design examples.