Sonel PAT-806-IT, User Manual

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PAT-806-IT
– USER MANUAL
41
Connect the mains plug of the tested device into the test socket
of the meter. The test consists in measuring the difference in
currents flowing in the L and N conductors. In addition, it is
possible to carry out the measurement with the probe connect-
ed to
R
ISO
- socket.
Settings and the measurement are as in 4.5.1.
Notes:
During the measurement in the test socket the voltage of mains is present.
During the measurement of a faulty device, RCD switch may be triggered off.
- Differential leakage current is measured as a difference between L current and N current (L and L
for IT). This measurement takes into account not only PE leakage current, but also leakage currents
caused by other earthed elements - e.g. water pipe. The disadvantage of this measurement is the in-
fluence of the common current value (flowing to the tested device through line L and returning
through line N) on the accuracy of the measurement. If this current is high, the measurement will be
less accurate (as described in the technical data) than the measurement of PE leakage current.
- Tested device must be turned on.
- In the half-time of the measurement, the meter automatically changes the polarity of the test socket
and as a result it displays the value of higher leakage current.
- The result of measurement may be affected by the presence of external fields and by the current
used by the device.
Note:
The differential method of leakage current measurement is permitted by EN 60974-4
standard as an alternative for measuring the primary leakage current performed during
periodic tests of welding equipment.