Reliability Forum

Reliability Info & Resources for
The Power Electronics Industry.

Webinar Slide

Abstract: Usually, Power Supply Units (PSUs) are designed and certified for an Overvoltage Category II (OVC) environment.

This means that they are intended for connection to the AC mains supply voltage through a supply cable and wall socket outlets.

However, more and more PSUs are nowadays included in the distribution panel, tariff meter or other equipment connected directly to the distribution network, which means that they are used in a harsher environment.

This means that they are connected to supply voltages at a higher OVC level, mostly OVC III. Sometimes, they are used in transformer substations, which means that they need to comply with requirements for OVC IV.

Telecommunications equipment, including 4G and 5G, is installed predominantly outdoors, on masts, rooftops, or in shelters. Power supplies for such equipment are subjected to higher transients from OVC III or OVC IV mains.

To cover the global market, a PSU needs to be designed for higher level requirements, such as OVC III or IV, or additional protective means must be utilized with power supplies designed for OVC II.

Builds on successful previous joint EPSMA/PSMA webinar ‘Lifetime Prediction of Power Supplies’ this one is based on the OVC paper published by the EPSMA in November 2022.

Paul Lee will Provide the explanation of OVC terms and application, how to interpret relevant standards, provide details of requirements for power conversion products installed in different OVC areas and describe how to adapt a lower OVC category power supply for operation in higher OVC environments.

This webinar will be followed by a Q&A session

Presenter: Paul Lee is the manager of the European Power Supplies Manufacturers Association and freelance author of over 500 articles, white papers and blogs on power subjects, as well as a book on power supply design techniques: Power Supplies Explained. As a chartered engineer and with a degree in electronics, Lee has owned a power supply manufacturing company and later worked as a Director of Engineering for Murata Power Solutions in the UK. Lee lives in Oxfordshire UK, is an associate of the Royal Photographic Society and holds a UK amateur radio license.

See the presentation here

PSMA/EPSMA Webinar: Guidelines for Lifetime Specification of Power Converters
 
Abstract: This webinar is a summary of a paper published by the European Power Supplies Manufacturers’ Association on the subject of Specification of Lifetime of Power Converters. Firstly, terms are defined; lifetime, MTBF, MTTF, FITS, reliability. The difference between lifetime and reliability expressed as MTBF is emphasized with examples of how they can be very different. Factors affecting lifetime for key components are listed and explained, then failure mechanisms, stress factors and lifetime estimation calculation methodology described. The details for one component type are given, then summary information given for other key components. Conclusions and recommendations are given for the format used in data sheets for lifetime specification, to enable realistic comparisons between products.
 
Presenter: Paul Lee, European Power Supplies Manufacturers’ Association
Paul Lee is the manager of the European Power Supplies Manufacturers’ Association and a freelance author of over 400 articles and blogs on power subjects as well as a book on power supply design techniques: ‘Power Supplies Explained’. As a Chartered Engineer and with a degree in electronics, Lee previously worked as a Director of Engineering for Murata Power Solutions.