Norelco shavers should be cleaned after every use; for Norelco rotary head shavers, lift off the razor's head assembly, and then brush out the razor chamber and the cutters. Every couple of months, remove the combs and cutters from the retaining plate, brush away any hair, soak them in cleaner and then lubricate them before returning them to the shaver.
Lubricating the cutter and the metal surfaces of the screen after cleaning is important. A lubricant such as Shaver Saver by Remington can be sprayed on the shaver while it is running to lubricate it. Around once a year, replace the shaver screen and cutter, or more often if the razor is used daily.