An electric cable intended for transmission of electric power.

An electric converter for converting an alternating current into a direct current.

A switchgear and controlgear bearing a set of switches for connecting and disconnecting the various circuits of an electrical system, as of a telegraph, telephone, etc.

A physical object that is a general term covering switching devices and their combination with associated control, measuring, protective and regulating equipment, also assemblies of such devices and equipment with associated interconnections, accessories, enclosures and supporting structures.

An ac power supply unit that maintains a continuous supply of electric power to the equipment it protects.

A circuit-breaker in which the contacts open and close within a highly evacuated envelope.

A physical object that consists of an electric motor and controller that is used to adjust the motor's operating speed.