Ricoh C231 Service Manual page 682

General Notes on this Feature
NOTE: 1) The durability of the PSU is improved compared to previous models.
2) The 100V machine does not have this mechanism, because voltages
more than 220 V will not occur.
3) The machine keeps a record, and you can check the data with SP 8-9
Data printout – Power failure. Refer to section 5-9-3.
4) Collect the logging data with the PSU board when it is needed for
investigation.
5) When the user turns the main power switch off, the machine detects this
as a 'momentary voltage drop' and a 'low voltage', and adds this to the
log for these two error types.
SM
ABNORMAL VOLTAGE PROTECTION
6-51 C267