Mitsubishi Electric MELSEC-A Series Manual page 242

[Countermeasures for preventing aluminum electrolytic capacitor characteristics deterioration]
Apply the rated voltage to the aluminum electrolytic capacitor for several hours to activate it. Or,
rotate products at the periodic inspection (in every 1 to 2 years).
[Reference]
The life of an aluminum electrolytic capacitor, even if not used, under a normal temperature
decreases approximately at 1/4 speed of the case when it is energized.
APPX
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