BS EN 61643-31:2019

What is BS EN 61643‑31 on Surge protective devices about? 

BS EN 61643‑31 is the 31st part of an international multi-series standard that focuses on low-voltage surge protective devices.  

BS EN 61643‑31 is applicable to Surge Protective Devices (SPDs), intended for surge protection against indirect and direct effects of lightning or other transient over-voltages. These devices are designed to be connected to the DC side of photovoltaic installations rated up to 1500 V DC. 

BS EN 61643‑31 gives devices that contain at least one non-linear component and are intended to limit surge voltages and divert surge currents. It also establishes performance characteristics, safety requirements, standard methods for testing, and ratings. 

Note 1: SPDs complying with BS EN 61643‑31 are exclusively dedicated to being installed on the DC side of photovoltaic generators and the DC side of inverters. 

Note 2: SPDs for PV systems with energy storage (e. g. batteries, capacitor banks) are not covered in BS EN 61643‑31. 

Note 3: SPDs compliant with BS EN 61643‑31 are designed to be permanently connected where connection and disconnection of fixed SPDs can only be done using a tool. 

Note 4: BS EN 61643‑31 does not apply to portable SPDs.  

Who is BS EN 61643‑31 on Surge protective devices for? 

BS EN 61643‑31 on surge protective devices is useful for: 

• Manufacturers and suppliers of surge protective devices 
• Dealers and distributors of surge protective devices 
• Designers of photovoltaic panels and surge protective devices  
• Services/ certification providers for photovoltaic panels and surge protective devices 

Why should you use BS EN 61643‑31 on Surge protective devices? 

Removable radiators are helpful for increasing the surface area for dissipating heat of the oil for the cooling purpose of the power transformer. 

BS EN 61643‑31 addresses safety and performance tests for surge protective devices (SPDs) to be installed on the DC side of photovoltaic installations. It helps you to protect photovoltaic panels against induced and direct lightning effects. 

BS EN 61643‑31 also gives the users, the tests that should be taken into account while installing photovoltaic panels and generators that help them to behave like current generators. These tests could help you make sure that their output current depends on the incident light intensity and temperature, and their short-circuit current is slightly higher than the operating output current.  

What’s changed since the last update? 

BS EN 61643‑31:2019 supersedes BS EN 50539‑11:2013+A1:2014, which is withdrawn. The main changes with respect to EN 50539-11:2013 are the complete restructuring and improvement of the test procedures and test sequences.