JDZ-35Q Casting Resin Epoxy Resin Indoor High Voltage Transformer

Voltage transformer(PT) and current Transformer(CT) are important electrical equipment of power system. They are responsible for the separation between high and low voltage systems and the conversion of high voltage to low voltage. Whether the wiring is correct or not is of great importance to the normal work of the equipment such as protection, measurement and monitoring. In the new installation PT, CT operation or replacement PT, CT secondary cable, the polarity test method to verify the correctness of PT and CT wiring, has been the necessary work procedures for relay protection staff.

o avoid polarity substitution is to find the "same name" of the input and output of the Transformer. The specific method is "point polarity". An example of how to point polarity is given here. The method is to connect the finger type multimeter to the secondary output winding of the transformer, and the multimeter hits the DC voltage gear. Then the negative pole of a dry battery is fixed to the primary output wire of the current Transformer. Using the positive pole of the dry battery to "point" the primary input wire of the current Transformer, so that a +(positive) pulse current will be generated in the primary circuit of the transformer; At the same time, observe which direction the needle of the pointer multimeter is "offset". If the needle of the multimeter is shifted from 0 to right, the needle is "turned back", which means that the "primary input end" of the current Transformer connected to the normal terminal of the finger type multimeter is not the same as the "secondary input end", which is called "reverse polarity" or "addition polarity".