Device for testing main changing casing tube CT polar

The utility model discloses a device for measuring CT polarity of main transformer bushing, comprising an interface unit for connecting with CT of the measured main transformer bushing, a CT primary polarity measuring unit for measuring primary polarity of CT of the main transformer bushing, a CT secondary polarity measuring unit for measuring the secondary polarity of CT of the main transformer bushing, a power supplying unit for supplying power for CT primary polarity measuring and CT secondary polarity measuring, a polarity displaying unit for amplifying secondary induced current of CT polarity measuring to transform into visual signals to display. The utility model can visually and accurately display CT polarity measuring results, and effectively avoid arching problem generated during rise of battery voltage.