12 Apr PAT – What is the difference between two types of leakage current?
A Leakage current is a current that flows from live parts of a device, through isolation, to the ground. PAT meters provide the measurement of four types of leakage current:
Replacement leakage current: current is measured after applying voltage between shorted L and N and PE (Class I devices) or a probe in contact with the device housing (Class II);
Ground leakage current: only current flowing through PE conductor of the tested device is measured (the leakage through other routes is not measured);
Differential leakage current: the difference between current flowing through L conductor and the current flowing through N conductor is measured – taking into account all current leakage routes;
Touch leakage current: the leakage current is measured by taking into account human perception and response in accordance with PN-EN 60990 (internal resistance of the test probe = 2kΩ).
Detailed description of the above measurements is presented the guide entitled “Testing the safety of electrical equipment” available on our website.