SPECIAL FEATURE
CIRCUIT PROTECTION & SWITCHGEAR
10 YEARS OF A BLUEPRINT FOR BEST PRACTICE Sean Smith, Managing Director of Michael Smith Switchgear, looks at the standards relating to low voltage switchgear.
I
t’s quite rare that issues arise with low voltage switchgear assemblies. When they do, it can be years after installation – and the consequences can be catastrophic. Increased load and prematurely ageing materials can cause under-rated components and poorly-designed assemblies to overheat and catch fire. That’s why, 10 years ago, BS EN 61439 became compulsory and superseded BS EN 60439. This was updated for the manufacture of low voltage switchgear and control gear assemblies. It redefined the minimum standard of how assemblies are designed, constructed and installed. In one fell swoop, the standard brought new order, safety and reliability to the design, manufacture and assembly of low voltage switchgear and control gear assemblies. BS EN 61439 removed loopholes from the withdrawn standard that had been used by the majority of the switchgear industry over the preceding years. The removal of Partial Type Tested Assemblies (PTTAs) from the standard – and a change in wording and description to the compulsory Design and Routine Verifications of all Assemblies – would make for a more consistent and safe LV switchboard marketplace. At least it would have done, had it been consistently and universally applied over the last decade.
Legal implications
Adherence with BS EN 61439 is necessary in order to meet wider legal safety obligations. This means it also limits the risk of potential liabilities in the future. For example, the Electricity at Work Act may become applicable once an assembly is in service. As BEAMA notes, this means that – in the event of an incident involving risk of injury or death – the Health and Safety Executive (HSE) will almost certainly become involved. If the HSE then determines that the fault was because of poor design or workmanship, the assembly manufacturer is implicated. Responsibility is generally not time barred, and those found to have broken the law face large fines or even prison.
gewiss.com 52 | September 2024
Circuit Protection & Switchgear (MSSL).indd 52
On a more straightforward commercial level, manufacturers making overblown or false claims about the performance of low voltage switchgear assemblies may fall foul of trade and consumer laws – potentially years after installation. Applying the applicable standard (BS EN 61439) to all assemblies helps to reduce the risk of both eventualities. It offers a level of defence against unforeseen accidents and gives users quality assurance. Demonstrating compliance with BS EN 61439 is not an absolute defence in all circumstances, but it is a good starting point and in most cases could be sufficient.
Breaking it down
So, what is in the standard? BS EN 61439 sets out a stage-by-stage guide to safety and performance requirements relating to low voltage switchgear and control gear assemblies used in industrial, residential and commercial settings. It covers specific requirements relating to assemblies, distribution boards, usage on construction sites and in public networks, and busbar trunking. Taken together it provides a way of testing the performance of either bespoke or standard assemblies. BS7671:2018 IET Wiring Regulations (18th Edition) defines a low voltage switchgear and controller assembly as: Combination of one or more low voltage switching devices together with associated control, measuring, signalling, protective, regulating equipment, with all the internal electrical and mechanical interconnection and structural parts (see BS EN 61439-1).
Blueprint for best practices
The result is that BS EN 61439 removes uncertainty for those building and fitting low voltage switchgear assemblies into the wider electrical system. As such, it offers a best practice blueprint, which provides a clear and detailed roadmap for manufacturers and installers for a standardised, safe assembly. When making their procurement decisions, users don’t often specify that their assemblies need to be compliant with BS EN 61439. It is often assumed. However, it’s an extremely effective method for all parties to avoid any difficult conversations in the future. There are
a vast range of verifications to be carried out and full compliance to the standard should be checked by the purchaser or end user. In summary, installing a switchboard that does not fully comply with BS EN 61439 breaches BS7671:2018 (18th Edition) Wiring Regulations for the installation.
Adherence with BS EN 61439 is necessary in order to meet wider legal safety obligations
Flexible solution
By adhering to the BS EN 61439 standard, manufacturers can ensure that their assemblies are legally compliant and safe for use. The quality assurance provides all parties with peace of mind, knowing that the low voltage switchgear assemblies they depend on to protect their electrical system are built to the latest standards of safety and performance. For assembly manufacturers, BS EN 61439 is flexible enough to allow creative solutions to bespoke client requests. No two switchboards are the same. Therefore, BS EN 61439 has enough flexibility to enable bespoke designs tailored to specific applications and requirements, which also fully comply and adhere to the standard. Taken together, it all means that – whether it’s a small commercial building or a large data centre – bespoke low voltage switchgear assemblies can be designed and built without compromising on safety or reliability. And we all know that adaptability is crucial in an evolving electrical landscape, where one-size-fits-all solutions rarely cut it. Michael Smith Switchgear, mssl.uk.com
Custom modular power solutions, scan to build now! electricalcontractingnews.com
@ElecConNews
/electricalcontractingnews
@ecn_magazine
electrical-contracting-news-ecn
28/08/2024 09:50