What is BS EN IEC 62271‑108 about? 
BS EN IEC 62271‑108 discusses high-voltage switchgear and r and controlgear. BS EN IEC 62271‑108 applies to high voltage alternating current disconnecting circuit breakers for operation at frequencies of 50 Hz and 60 Hz on systems having voltages above 52 kV.
BS EN IEC 62271‑108 covers single switching devices which perform the functions of both a circuit-breaker and a disconnector by means of contacts housed in a single enclosure, and in which the circuit-breaker contacts in the open position satisfy, or contribute to, the isolating requirements of the disconnector function.
BS EN IEC 62271‑108 details the requirements for a disconnecting circuit-breaker, identifying where these differ from the separate requirements of a discrete circuit-breaker and a disconnector.
Who is BS EN IEC 62271‑108 for?
BS EN IEC 62271‑108 on high voltage alternating current switchgear and controlgear is useful for:
- Manufacturers of circuit breakers for high-voltage AC
- Companies dealing with circuit breakers for high-voltage AC
- Retailers and suppliers of circuit breakers
Why should you use BS EN IEC 62271‑108?
As the voltage level is high the arcing produced during switching operation is also extremely high. The high-voltage switchgear deals with the voltage which is above 52kV.
Circuit-breaker is a mechanical switching device, capable of making, carrying, and breaking currents under normal circuit conditions and making, carrying for a specified time, and breaking currents under specified abnormal circuit conditions such as those of short circuits.
As a user of BS EN IEC 62271‑108, you will be provided with the guidance on transport, storage, installation, operation instructions, maintenance, safety, and influence of the product on the environment.
BS EN IEC 62271‑108 gives general rules and common safety requirements for high-voltage alternating current disconnecting circuit-breakers and provides you the essential constructional, performance, and test requirements to enable the design, evaluation, and safe operation of these circuit breakers.
BS EN IEC 62271‑108 ensures you the quality and safety of the components and performance of the product by testing and verifying the characteristics necessary for high-voltage alternating current disconnecting circuit-breakers. You can attain electrical protection from thermal and mechanical stresses due to operating overloads. 
With an efficient circuit breaker as per BS EN IEC 62271‑108, leakage of current can be detected, and operators can be guarded before any serious harm is done.
As a user of BS EN IEC 62271‑108, you will be able to establish a safe and reliable electric supply system in commercial or industrial facilities of varied sizes. In the event of a short-circuit or failure of the power system, efficient high-voltage alternating current disconnecting circuit-breakers will help eliminate damage to the equipment and prevent disruption to the end-user. The hazardous effects from excessive currents can also be mitigated with well-functioning circuit-breakers. Overall, adopting the global safety standards defined in BS EN IEC 62271‑108, can instil credibility and acceptance for your business.  
What’s changed since the last update?
BS EN IEC 62271‑108:2020 supersedes BS EN 62271‑108:2006, which is withdrawn. It includes:
- References have been reviewed, updated, and rated static terminal load and static terminal load test have been removed and a design requirement for static mechanical loads has been included
- Additional type tests for auxiliary and control circuits have been included and X-radiation test procedure for vacuum interrupters has been included
- Type test for testing of interlocking device and type test for testing of temporary mechanical locking devices have been included, specific requirements for making and breaking tests on class E2 disconnecting circuit-breakers have been removed
- BS EN IEC 62271‑108:2020 has been adapted to some of the changes introduced in IEC 62271-102:2018 and BS EN IEC 62271‑108:2020 has been restructured according to IEC 62271-1:2017
- BS EN IEC 62271‑108:2020 has been adapted to some of the changes introduced in IEC 62271-100
