IEC 61643-31-2018 PDF

Full title and description

IEC 61643-31:2018 — Low-voltage surge protective devices - Part 31: Requirements and test methods for SPDs for photovoltaic installations. This international standard specifies performance, safety, marking and test methods for surge protective devices (SPDs) intended to be connected to the DC side of photovoltaic (PV) installations (rated up to 1 500 V DC) to protect against lightning and other transient overvoltages.

Abstract

This part of IEC 61643 defines electrical, mechanical and environmental requirements and standard test procedures for SPDs dedicated to PV applications (DC side of PV generators and of inverters). It addresses classes of tests (Class I / II / III), end-of-life behaviour, disconnectors and status indication, and excludes SPDs for PV systems with energy storage, portable SPDs and certain two‑port SPD designs. A corrigendum issued in 2022 is incorporated into published copies.

General information

• Status: Published / current (international standard; stability date indicated by IEC through 2026).
• Publication date: 10 January 2018 (IEC publication).
• Publisher: International Electrotechnical Commission (IEC).
• ICS / categories: 29.240.01, 29.240.10 (surge arresters / low-voltage surge protective devices).
• Edition / version: Edition 1.0 (2018). Corrigendum 1 published June 2022.
• Number of pages: 107 pages (main publication).

Scope

Applies to SPDs that contain at least one non-linear component and are intended to limit surge voltages and divert surge currents on the DC side of PV installations (string, combiner box and inverter DC inputs) with ratings up to 1 500 V DC. The standard sets required tests and ratings for permanent, fixed SPDs (disconnection or removal only with a tool). It does not cover SPDs for PV systems that include energy storage (batteries, capacitor banks), portable SPDs, nor certain two‑port SPDs that include specific series impedances (as referenced to IEC 61643-11).

Key topics and requirements

• Classification of SPDs and test classes (Class I, II, III) to simulate different lightning and transient scenarios.
• Electrical performance parameters: residual voltage/clamping behaviour, total discharge current, continuous current ratings and declared maximum discharge current where applicable.
• Safety and end-of-life requirements: disconnectors/thermal protection, clear fault indication and behaviour under overstress.
• Type, routine and acceptance tests: operating duty tests, dielectric withstand, insulation resistance, mechanical strength, environmental (damp heat, temperature cycling) and electromagnetic compatibility tests.
• Marking, documentation and installation information specific to PV applications (voltage rating, nominal current, type of SPD, intended installation point).
• Exclusions and special conditions: guidance on SPDs not suitable for PV systems with storage and limitations for two‑port SPDs.

Typical use and users

Used by photovoltaic system designers and specifiers, SPD and component manufacturers, testing laboratories, certification bodies, electrical installers and maintenance teams, and utilities or EPC contractors working on PV plants. It is referenced when selecting, testing and certifying DC surge protection modules for residential, commercial and utility-scale PV installations.

Related standards

Closely related to other parts of the IEC 61643 series, in particular IEC 61643-11 (SPDs for AC low-voltage power systems — requirements and test methods) and IEC 61643-21 (SPDs for telecommunications/signalling networks). It also references test technique standards such as IEC 62475 for high-current test definitions and other normative documents used for test setups and measurement methods. Regional/adopted versions exist (for example EN/IS adaptations).

Keywords

IEC 61643-31, surge protective device, SPD, photovoltaic, PV, DC, low-voltage, 1500 V DC, test methods, clamping voltage, discharge current, end-of-life, disconnectors, thermal protection.

FAQ

Q: What is this standard?

A: IEC 61643-31:2018 is an international standard that specifies requirements and test methods for surge protective devices intended for the DC side of photovoltaic installations (up to 1 500 V DC).

Q: What does it cover?

A: It covers performance characteristics, electrical and mechanical tests, environmental requirements, marking and safety requirements for permanently installed DC SPDs in PV systems. It includes tests simulating lightning and switching transients and defines end-of-life and fault behaviour; it excludes SPDs for PV systems with energy storage and certain two-port or portable designs.

Q: Who typically uses it?

A: PV system designers, SPD manufacturers, test labs and certification bodies, electrical contractors and plant operators use the standard to select, test and verify DC surge protection equipment for PV installations.

Q: Is it current or superseded?

A: The document was published in January 2018 (Edition 1.0) and a corrigendum was issued in June 2022; IEC lists a stability date indicating the publication will remain unchanged until at least 2026 unless reconfirmed, amended, withdrawn or revised. Users should check IEC communications for any future revisions.

Q: Is it part of a series?

A: Yes — it is Part 31 of the IEC 61643 series (Low-voltage surge protective devices). Other parts address SPDs for AC power systems (Part 11), telecommunications (Part 21) and additional application-specific requirements.

Q: What are the key keywords?

A: Photovoltaic, DC SPD, surge protection, low-voltage, 1500 V DC, clamping/residual voltage, total discharge current, end-of-life disconnect, test methods, IEC 61643 series.