Hitachi RAK-25NHA1 Instruction Manual page 15

Explanation of the sleep timer
The device will control the FAN SPEED and room temperature
automatically so as to be quiet and good for people's health.
NOTE
G If date or current time is not set, sleep timer can not be set.
If you set the sleep timer after the off-, on/off- or off/on-timer
G
has been set, the sleep timer becomes effective instead of
the off-, on/off- or off/on-timer set earlier.
G You can not set other timer during sleep timer operation.
After sleep timer time is up and when press sleep button
G
again, the sleep timer will be set as last setting.
G Sleep timer effective only once.
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