How is leak current measured?

QWhy can leak current be measured by clamping two power supply lines?


If there is no leak current, the magnetic flux generated around the conductive wire from the power supply and the magnetic flux of the current in the returning wire cancel each other out, causing the clamp leak current meter to indicate a reading of 0. However, if there is a leak on the load side of the clamped conductor, there will be a difference between the magnetic flux of the outgoing current and the returning current, and the magnetic flux corresponding to this difference will be the current that is leaking on the load side. Similar leak current measurement can be performed for a 3-phase circuit by clamping all three wires at once.

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Hioki offers two types of instruments for measuring leakage current