A rewireable UK plug has marked terminals for line (L), neutral (N) and protective earth (E or the earth symbol). Terminal markings and the product instructions govern the connections; a remembered left/right view can be reversed.

Any permitted plug inspection starts with the plug removed from the socket and kept disconnected. Do not open a moulded plug body or an appliance enclosure. Damage, overheating, an unidentified cable or uncertainty about the repair calls for appropriate help. Read Safe Isolation to distinguish disconnection from proof that unknown wiring is safe.