IEC TC 37B

IEC SC 37B – Components for Low-Voltage Surge Protection

IEC Subcommittee 37B (IEC SC 37B) develops International Standards for components used in low-voltage surge protection devices (SPDs).
These standards specify the safety, performance, testing, and reliability requirements for surge protection components designed to protect electrical and electronic equipment from transient overvoltages.

IEC SC 37B publications cover components such as metal oxide varistors (MOVs), gas discharge tubes (GDTs), transient voltage suppressor (TVS) diodes, spark gaps, and other protective elements.
The standards ensure effective protection against lightning-induced surges, switching transients, and other electrical disturbances.

List of Standard (IEC TC 37B):

1. IEC 61643-311:2013 Components for low-voltage surge protective devices – Part 311: Performance requirements and test circuits for gas discharge tubes (GDT)
2. IEC 61643-312:2013+COR1–2013 Components for low-voltage surge protective devices – Part 312: Selection and application principles for gas discharge tubes
3. IEC 61643-321–2001 Components for low-voltage surge protective devices – Part 321: Specifications for avalanche breakdown diode (ABD)
4. IEC 61643-331:2018 Components for low-voltage surge protection – Part 331: Performance requirements and test methods for metal oxide varistors (MOV)
5. IEC 61643-341:2001 Components for low-voltage surge protection – Part 341: Performance requirements and test circuits for thyristor surge suppressors (TSS)
6. IEC 61643-351:2016 Components for low-voltage surge protective devices – Part 351: Performance requirements and test methods for telecommunications and signalling network surge isolation transformers (SIT)
7. IEC 61643-352:2018 Components for low-voltage surge protection – Part 352: Selection and application principles for telecommunications and signalling network surge isolation transformers (SITs)