The time out setting denotes the amount of time a client can remain idle before being disconnected. Idle is considered as not sending/receiving data and issuing no commands for the specified amount of time as listed below.
FTP/FTPS/SFTP – 3 Minutes
WebApp – 15 Minutes
Can time out settings be adjusted?
FTP/FTPS/SFTP - No these cannot be adjusted.
WebApp - Yes, but up to 60 minutes only and will affect all users. Submit a support request if you would like to have the default value increased for your site.