-★ 1. In order to understand this problem, let's first talk about the history of current transformers: in the early current transformers, the primary winding was not the current epoxy packaging and core-piercing structure, but the structure with winding and core-winding. In order to prevent high voltage from entering the secondary winding during breakdown, the regulations stipulate that the secondary winding must be grounded.

★ 2. The current transformer adopts a new technology-epoxy resin (secondary winding) sealing package, and the risk caused by breakdown is very low. But the regulation is the regulation, which must be observed, so when installing the current transformer, the secondary grounding must be done.