Voltage tester for testing operation voltage between lines of IT system for transporting electric current to operate electric motor of e.g. electric motor car, has coupler arranged between lines and coupling source voltage between lines

摘要

The tester has a display (2) arranged between lines (3, 4) of an electrical low-voltage network, and displaying an operation voltage between the lines. A coupler (1) i.e. inductive coupler such as transmitter, is arranged between the lines parallel to the display and couples a source voltage between the lines. An alternating current (AC) voltage source is connected with the coupler, and galvanically decoupled from the network for producing the source voltage. The voltage source includes a signal generator for producing a voltage signal e.g. square-wave voltage signal (7). An independent claim is also included for a method for testing an electrical network for absence of voltage.