Current transformer wiring principles and precautions for use

- Jul 06, 2020-

1. No open circuit is allowed. The secondary open circuit is easy to cause a safety accident, because the secondary open circuit will cause the iron core to overheat and induce a high voltage.

2. One point must be grounded. Once the current transformer is measured as high voltage, if there is one point to ground, the high voltage can be introduced into the earth, but pay attention to the two points of grounding, so as to avoid shunting.

3. The protection level and the measurement level cannot be connected wrongly. Once these two are connected wrongly, it may lead to insensitive relay protection and inaccurate energy measurement.

4. Unused windings need to be short-circuited, so as not to affect the measurement accuracy, but the current transformer has multiple taps. Unused taps need to be short-circuited.

Precautions for use of current transformer

1. Generally speaking, the connection of the current transformer is connected according to the reduced polarity, so the polarity connection should be correct. Once the connection is wrong, it will lead to inaccurate measurement and even short circuit.

2. In order to prevent the secondary winding from causing high-voltage electricity to enter the low-voltage side, damage the instrument and cause personal injury, a protective ground point should be set.

3. For transformers using energy measurement, if the secondary circuit is used, then no automatic device is required.