Under normal working conditions, according to my country's power design principles, the current on the neutral line should be equal to the current on the live line to maintain the balance of the circuit. This means that under normal operating conditions, the current on the neutral line should be close to zero. But in real life, there are not that many cases where the current on the neutral line is close to zero.
However, in actual situations, due to factors such as leakage of electrical equipment and imperfect circuits, there may be a small amount of leakage current on the neutral line. According to the standards of the International Electrotechnical Commission (IEC), the leakage current limit on the neutral line is usually below a few milliamperes (mA).
Specifically, for home and office environments, it is generally accepted that the leakage current on the neutral line should be less than 5 milliamps (mA). This is to ensure the safety of the circuit and prevent electric shock and other electrical failures.
However, it should be noted that if the current on the neutral line significantly exceeds the normal range, it may be caused by circuit failure, equipment damage, line short circuit, etc. In this case, timely inspection and repair should be carried out to ensure the safe operation of the circuit.
