1. The secondary side of the voltage transformer must have a grounding point. This is mainly for safety reasons. When the insulation between the primary and secondary windings is broken by high voltage, the high voltage on the primary side will hit the secondary side, and the grounding on the secondary side will ensure the safety of personnel and equipment. In addition, the phase voltage can be supplied to the insulation monitoring device by grounding.
2. The secondary side of the current transformer should have a little grounding. Since the primary side of the high-voltage current transformer is high voltage, when high-voltage breakdown occurs due to insulation damage between the two coils, the high voltage will enter the low voltage. If the secondary coil is grounded at one point, the high voltage will be introduced into the ground to keep the secondary coil at ground potential, thus ensuring the safety of the person and equipment.https://www.ctsensorducer.com/