power consumers the power consumption falls from p l to p 1 if the machine is not operated following the expiration of a further predefined time interval t 2 t 1 then a second energy cost saving step begins at a time t 2 with this second step further power consumers such as units and control components are switched off this is a group of power consumers having a longer start up time t h2 where t h2 gt t h1 of for example more than 2 minutes as a result of switching off this group of power consumers the power consumption falls from p 1 to p 2 if the machine is not operated following the expiration of a further predefined time interval t 3 t 2 then a third stage of the energy cost saving begins at a time t 3 apart from the central unit of the computer 35 all of the power consumers are switched off the power consumption p 3 lt p 2 is at a minimum if the machine is started up again at a time t 4 under time control or as a result of an operator input then all of the power consumers which were still in operation between the times t 0 and t 1 are now powered as necessitated by.