How to install the residual current transformer?

1. Choose a suitable installation location
Easy to maintain: The residual current transformer should be installed in a place that is easy to maintain and as far away from strong magnetic fields as possible.
Close to the protection device: It is usually installed on the output side of the current transformer, close to the protection device, so that faults can be discovered in time and measures can be taken.
Installation method: The transformer can be directly hung on the cable or fixed in the distribution box.
2. Threading method
Distinguish the lines: Before threading, the phase line, N line and PE line in the power grid should be distinguished.
Phase line and N line: The phase line and N line must pass through the residual current transformer together, and the PE line cannot pass through the transformer.
Avoid false operation: If the N line does not pass through the transformer together with the phase line, once the three-phase load is unbalanced, current will flow through the N line, and the detector will detect the current signal, that is, false operation will occur.
N lines in different circuits: N lines between different circuits must not be connected at multiple points or grounded repeatedly, otherwise it will cause false operation.
3. Installation steps
Circular residual current transformer:
Take out the residual current transformer and unscrew the screws of the residual current transformer.
Pass the three phase wires and the neutral wire of the measured circuit through the residual current transformer at the same time and in the same direction (it must be four wires and pass through in the same direction).
Close the residual current transformer and tighten the screws. Both screws must be tightened.
Fix the residual current transformer.
Open-type residual current transformer:
Pass the phase wire and the neutral wire of the measured circuit through the residual current transformer at the same time and in the same direction.
Close the residual current transformer until you hear the sound of the buckle snapping.
4. Wiring precautions
Wiring accuracy: Ensure the polarity of the primary winding and the secondary winding is correct to avoid wrong connection.
Grounding wire: The grounding wire of the residual current transformer should be reliably connected, and the grounding resistance should meet national standards.
Secondary side is strictly prohibited from being open: The secondary side of the residual current transformer is strictly prohibited from being open.
5. Debugging and maintenance
Check the wiring: Check whether the wiring of the residual current transformer is correct. After confirming that it is correct, conduct a power-on test.
Verification: Use standard test instruments to verify the residual current transformer to ensure its accuracy.
Simulate faults: Simulate residual current faults to check whether the residual current transformer can operate in a timely and accurate manner.
Regular inspection: Regularly check the operating status of the residual current transformer to ensure its normal operation.