Assessing the Reliability of MEAN WELL Power Supplies
MEAN WELL was established in 1982 and has gained a global reputation for the design and manufacture of superior quality and high cost-performance power supplies.
With switch-mode power supplies, the number of components used in the design can be anything from dozens to hundreds, depending on the power output and topology.
Of course, each component is designed in due to necessity.
Ensuring a long service life and assessing reliability are priorities in the power supply industry.
There are two parameters that are usually cited in product data sheets that enable you to assess the anticipated service life and reliability of a power supply.
- Meantime Between Failure (MTBF)
In this blog post we discuss both the MTBF and the lifecycle parameters
MTBF and Lifecycle are not a guarantee of how long a single power supply will last. Rather, the give an average expectation.
Lifecycle is determined by measuring the temperature rise of the electrolytic capacitors under their maximum operating temperature under a full load to estimate the approximate life of the power supply.
This is usually expressed in the data sheet in 1000’s of hours.
Mean Time Between Failure
The calculation to derive the MTBF data is more involved than that to determine the Lifecycle value. MTBF can be calculated using two different methodologies: "part count" and "stress analysis".
The standards MIL-HDBK-217F Notice 2 and TELCORDIA SR/TR-332(Bellcore) are commonly used to calculate MTBF and you will see these referenced in most MEAN WELL data sheets.
MIL-HDBK-217F is a United States military standard, and TELCORDIA SR/TR-332(Bellcore) is a commercial regulation.
The only difference is that they are derived from differential equations.
The MTBF equation for electrical component failure rate contains many variations, including quality factor, environment factor, basic failure factor…etc.
The advancements in the design of components and the processes used to manufacture them results in better quality and stability.
Therefore, if a power supply is updated to use a newer component of a higher quality, it is possible to adjust the pQ parameter in the above equation to enhance the MTBF value of the power supply.
To ensure the relevance of the MTBF, MEAN WELL uses the below table to establish which pQ factor should be used in the above MTBF equation.
The continuous pursuit of innovation and optimisation is an ongoing mission for MEAN WELL. As a result, MEAN WELL’s quality is continuously evolving as newer components and suppliers are selected.
This is why you will see many power supplies offered by MEAN WELL with warranty periods of 5 years or longer.
For further information on MEAN WELL power supplies, please do not hesitate to contact MEAN WELL Australia.