Precautions for use of current transformer

- Jul 20, 2020-

1. The polarity connection must be correct. Current transformers are generally marked with reduced polarity. If the polarity is not connected correctly, it will affect the measurement. Even when multiple current transformers are connected in parallel on the same line, it will cause a short circuit accident.

2. The secondary circuit shall be provided with a protective earth point and be reliably connected. In order to prevent the high voltage from entering the low voltage side after the insulation breakdown between the primary and secondary windings, which endangers the safety of the person and the instrument, the secondary side of the current transformer should be provided with a protective grounding point. Only one grounding point is allowed to be connected. The box terminal of the device is grounded.

3. The secondary winding is not allowed to open during operation. Otherwise it will cause the following serious consequences:

(1) High voltage appears on the secondary side, endangering the safety of the person and the instrument;

(2) Overheating may damage the winding;

(3) Increase the measurement error.

4. The secondary circuit of the current transformer used for energy measurement should not be connected to relay protection devices and automatic devices to prevent mutual influence.