You can enter how long the machine must be idle (the maximum setting is 90 Mins and the default setting is 15 Mins) before it enters Sleep Mode. The timer will restart if any operation is carried out on the machine.
If a wireless network is enabled, the machine will not enter Sleep mode. To disable the wireless network, press

,
Network and then
WLAN. Swipe up or down, or press

or

and then press
WLAN Enable and
Off.
1 | Press  . |
2 | Press General Setup. |
3 | Press Ecology. |
4 | Press Sleep Time. |
5 | Enter the length of time the machine will be idle before entering Sleep Mode. |
6 | Press  . |