Al E-Cap

[giulias]

I'm looking for someone with direct experience on Al Electrolytic Capacitor on high temperature (85°C case) application. Suppliers provide info on load life, I'd like to understand better how much I can trust suppliers guarentee life categories and which are the guideline to select E-Cap for a good reliability application
thank you in advance
giulia

 

[OperaHouse]

Been a few years since I did an investigation on a product that only lasted about a year that had 85C caps in it operating at elevated temperatures. A number (every one of them in fact)of these had failed in the same time period The formula is in most catalogs and (if I still remember) 85C is for 4,000 hours. A fact that many people ignore. Given that this device was in 24 hour operation and knowing the operating temperature, the formula for how long it would last was right on the money. I love it when formulas work! The failure mode was the capacitance would go to almost zero.

 

[jims99]

If you really plan to opearate the electrolytic cap at 85 C, make sure you always specify a much higher rating such as 105C or better 125C. Also, use "computer grade" types that have lower leakage current and have lower ESR (equiv-series-res) to minimize self-heating effects. They may cost more, but's it's worth it.
Unfortunately, the failures occur over time (months or years) so simple bench tests won't pick prone to failure.

Jim

 

[nismofan]

My company is looking at using the name brand "Surge" capacitor aka "Lelon". Does anyone has any experience with this capacitor name brand?

 

[ScottyUK]

We have had excellent results from Evox-Rifa's PEH-169 105[°]C series in high temperature, high ripple current applications. Ambient was approx 70[°]C, life was better than predicted. It's a job or two ago - sorry I can't be much more specific.



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