Precautions when Miniature Current Transformer is connected 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. Choose the appropriate variation according to the current to be measured, otherwise the error 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 is not allowed to be disconnected. When the Miniature Current Transformer works normally, the secondary side is approximately short-circuited. If it is suddenly turned on, the excitation electromotive force suddenly changes from a small value to a large value, and the magnetic flux in the iron core exhibits a severely saturated flat top. Therefore, when the magnetic flux passes through zero, the secondary winding will generate a high peak wave, the value of which can reach thousands of volts or even tens of volts, which has a great impact on the safety of crisis handlers and the insulation performance of instruments.

In addition, an open circuit on the secondary side will generate hundreds of volts of voltage on E2, and if you touch it, it will cause an electric shock accident. Therefore, the secondary side of the Miniature Current Transformer is provided with a short circuit switch to prevent the primary side from being disconnected. During use, once the secondary side is disconnected, the circuit load should be removed immediately and then stopped. Once everything is processed it can be reused.

When installing the protective Miniature Current Transformer, the protection of the primary protection device should be removed as much as possible. area to be set. If there are two sets of current transformers and the location allows, they should be placed on both sides of the circuit breaker so that the circuit breaker is within the cross protection range.

In order to reduce the damage of the internal fault of the generator, a current transformer for automatic adjustment of the excitation device should be installed on the output side of the generator stator winding. To facilitate analysis and detect internal faults before the generator is incorporated into the system, the Miniature Current Transformer for measuring instruments should be installed at the neutral point of the generator.