What should be paid attention to when connecting miniature current transformers in series

The wiring of the miniature current transformer should follow the series principle: the primary winding should be connected in series with the circuit under test, and the secondary winding should be connected in series with all instrument loads. Appropriate changes should be selected based on the measured current, otherwise errors will increase. At the same time, the secondary side must be grounded to prevent damage to the insulation when the primary side is pressed into the secondary low voltage side, resulting in personal and equipment accidents.

The secondary side cannot be disconnected. When the miniature current transformer is working normally, the secondary side is approximately short-circuited.

When the equipment maintains the miniature current transformer, the protection of the primary maintenance equipment should be cancelled as much as possible. If there are two sets of current transformers and the orientation is acceptable, they should be placed on both sides of the circuit breaker so that the circuit breaker is within the cross maintenance range.

In order to reduce the damage caused by the internal fault of the generator, the current transformer used to automatically adjust the excitation equipment should be installed on the output side of the generator stator winding. In order to facilitate analysis and find internal faults before incorporating the generator into the system, the miniature current transformer used for the measuring instrument should be installed on the neutral point of the generator.