Surge Protection Standards: An Overview of Applications

International standards organizations establish strict specifications for testing the effects of surges on electrical equipment. Transient surges are extremely diverse and can cause significant damage.
For standardization purposes, physical phenomena have been defined as standardized waves:

  • Voltage wave: 1.2/50-μs wave

  • Current waves: 8/20-μs wave and 10/350-μs wave

The technical characteristics of surge protective devices (SPDs) are governed by various country-specific and global standards.

Overview: Important Standards by Application Area

  • Low-voltage systems: IEC 61643-11 (International), EN 61643-11 (Europe), DIN EN 61643-11 (Germany), NF EN 61643-11 (France), UL 1449 (USA)

  • Photovoltaic systems: IEC 61643-31 (International), EN 61643-31 (Europe)

  • Telecommunications: IEC 61643-21 (International), EN 61643-21 (Europe), UL 497 A/B/E (USA), ITU-T Recommendations K11, K12, K17, K20, K21, K36

Standards for AC Applications (Alternating Current)

CITEL AC surge protection devices comply with all relevant safety standards to ensure reliable system operation. The AC standards are divided into three types of documents:

1. Product standards

These regulations define the test procedures for surge protection manufacturers:

  • International: IEC 61643-11

  • Europe: EN 61643-11

  • Germany: DIN EN 61643-11

  • USA: UL1449 (5th edition)

2. Installation standards

These guidelines govern the proper installation of AC surge protection devices:

  • International: IEC Guide 61643-12

  • Europe: CLC/TS 61643-12

  • Germany: DIN CLC/TS 61643-12

  • USA: IEEE C62-41

3. Standards for Product Selection

These documents govern the selection of the appropriate protective device in accordance with electrical regulations:

  • International: IEC 60364-4-443 and 5-534

  • Europe: HD 60364-4-443 and 5-534

  • Germany: DIN VDE 0100 (Parts 443 and 534)

  • USA: NEC Art. 280 & 285

Standards for DC and Photovoltaic (PV) Applications

The protection of PV systems against transient overvoltages is strictly regulated by law and standards. In addition to Supplement 5 of the lightning protection standard DIN EN 62305-3 (VDE 0185-305-3), specific application rules apply.

The Application Standard IEC 61643-32

The international standard IEC 61643-32 governs the selection and application of SPDs in photovoltaic installations. In Germany, national implementation is carried out via VDE V 0675-5-32 (replacing VDE V 0675-39-12).


The key provisions of IEC 61643-32 include:

  • Measures to increase system safety and system availability

  • Protection concepts for buildings with and without external lightning protection

  • Calculation and compliance with the separation distance

  • Use of surge protection in ground-mounted systems

  • Requirements for the DC and AC sides of the installation


Legal Requirement for Installing SPDs in PV Systems

The installation of surge protection devices is mandatory for photovoltaic systems. The standards clearly stipulate this:

  • IEC 61643-32 (text): “The installation of SPDs on the DC and AC sides of a PV installation is mandatory unless indicated otherwise by a risk assessment.”

  • Protection of data lines: “When SPDs are installed to protect the PV system, it is also necessary to protect any telecommunications and signaling circuits that are part of the PV system.”

  • DIN VDE 0100-712: This standard refers to Supplement 5 of DIN EN 62305-3. It stipulates: If DIN VDE 0100-443 requires surge protection for the AC side, it must also be installed on the DC side of the PV system.

  • Selection Guide: The informative Annex C of DIN VDE 0100-712 provides the exact minimum requirements for the proper selection of equipment for PV systems mounted on or attached to buildings.

References: IEC 61643-11; EN 61643-11; DIN EN 61643-11; NF EN 61643-11; UL 1449; IEC 61643-31; EN 61643-31; IEC 61643-21; EN 61643-21; UL 497 A/B/E; ITU-T Recommendations (K11, K12, K17, K20, K21, K36); DIN EN 62305-3 (VDE 0185-305-3); IEC 60364-4-443 and 5-534; NEC Art. 280 & 285.