Since the setting value, integrated value (electric energy (consumption, regeneration), reactive energy, periodic electric energy, pulse count and operating time) is stored into nonvolatile memory, it will not be lost.
It will integrate the last value (before power failure) after recovering.
Since momentary value (current, voltage, electric power, reactive energy, apparent power, power factor, frequency, harmonics　current and harmonics voltage) will be updated per data updating cycle, the value before power failure is not stored.