Olivetti D-COPIA 300MF Operation Manual page 71

Basic Operation
Make sure that the indicator is off.
In case of not using the machine for extended period of time
CAUTION:
If the machine will not be used for hours (overnight, etc.), turn
the main power switch off. If it will not be used for an extended period of
time (vacations, etc.), remove the power plug from the outlet for safety
purposes.
CAUTION:
Do not turn the main power switch off when the optional fax
kit is installed. If you turn the main power switch off, you cannot receive
FAX messages.
OPERATION GUIDE 3-3