WORKPLACE SAFETY E


lectric shock and electrically caused fire related to the use of electrical products cause thousands of injuries and even deaths around the world each year, whether because of poor design, inadequate maintenance, or unintended use.


Electrical safety testing is carried out to evaluate the potential risks of electrical shocks and fire when products are used. It helps manufacturers to:


Achieve compliance with relevant regulation and standards in different global markets.


Discover and eliminate any problems in the product early on.


Avoid expensive product recalls.


Reduce the risk of expensive litigation should a product cause injury.


Meet customer demands to demonstrate dedication to safety.


Generally, safety standards, whether you are applying the Low Voltage Directive for CE/UKCA marking, or at a higher level for international approval (e.g. CB scheme, NRTL Certification or other Global Market Access requirements) require some type of testing. IEC, EN or NRTL approval is required when the relevant standard requires third-party evidence of compliance in the form of certification and/or an accredited test report. In general, IEC covers most of the world, EN covers EU requirements, NRTL covers North American requirements.


The key principles of safety, against which a product would be tested, are generally considered as:


Electric shock hazards Energy hazards Heat and fire hazards Mechanical hazards Chemical hazards Radiation hazards


Having an accredited product safety test report, with appropriate certification helps manufacturers to achieve compliance with regulation and requirements in various global markets. It may also help them to discover any problems in the product early on and avoid expensive product recalls. Also,


ELECTRICAL SAFETY TESTING CONSIDERATIONS


the risk of expensive litigation should a product cause injury is reduced.


Each test standard for a specific product type provides guidance as to how its requirements are met, with relevant testing and compliance criteria, documentation, and product marking requirements. It is important to note that safety standards require compliance under normal, abnormal (foreseeable misuse, such as covering of ventilation openings, paper jams, stalled motors, etc) and single fault conditions. Some of the tests might damage a sample, but this does not necessarily mean a non-compliance!


PREPARATION


As manufacturers are under pressure to maintain quality, minimising the costs and time associated with electrical testing is vital. It is therefore important to be properly prepared before products are sent to the test laboratory.


The product test laboratory sees many different and often innovative designs each year and may not be familiar with your product, so you must brief them fully on the design, intended use, and operation in advance of testing. In general, this will include:


1.Brief description of operation (including temperature, humidity and whether in a clean, dry or wet and/or dirty environment)


2.Marketing material (e.g. product datasheets); schematic diagrams, block diagrams, PCB & component layouts & constructional drawings


3.Parts lists/BOMs 4.User, installation & service manuals


5.Specifications/details/approval documentation for safety critical components (e.g. batteries, enclosure plastics, PCB material, etc.)


These are all key items which will enable the preparation of an accurate test programme. If adequate information is not available prior to the start of testing, it is likely that delays and further costs could be incurred.


IN THE TEST LABORATORY


Working samples must be able to be operated at full load. The laboratory will confirm the number of samples required, and will confirm whether they should be potted, open enclosures or sealed etc. They may also require representative loads for some outputs.


14 SUMMER 2025 | INDUSTRIAL COMPLIANCE


By Dennis Butcher, senior engineer at TÜV SÜD


They will also need some safety critical components for strip-down and measurements, such as unpotted/unvarnished transformers, alongside components which are likely to be damaged during fault testing and which can be easily replaced in the laboratory, such as fuses and leaded components.


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